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Wildland firefighters are exposed to metal(loid)s released during wildfires through vegetation combustion, which also promotes remobilization of accumulated anthropogenic metal(loid)s. Studies biomonitoring metal(loid)s exposure promoted exclusively by wildfire suppression activities are lacking. This work aimed to characterize, for the first time, the impact of real-life wildland firefighting operations on urinary levels of priority pollutant metal(loid)s [14 included in ATSDR, 11 in USEPA, and 4 in Human Biomonitoring for Europe Initiative priority lists] in firefighters. Spot urines were sampled pre-exposure (105 non-smokers, 76 smokers) and post-exposure to firefighting activities (20 non-smokers, 25 smokers); among those, paired samples were collected from 14 non-smoking and 24 smoking firefighters. Smokers displayed significantly higher baseline levels of zinc (28 %), lithium (29 %), cadmium (55 %), rubidium (13 %), and copper (20 %) than non-smokers. Following wildfire suppression, the concentration of the WHO potentially toxic metal(loid)s rose from 2 % to 3 % in smokers and 2 % to 5 % in non-smokers (up to 4 % for all firefighters and up to 5 % in paired samples). Levels of nickel (33-53 %), antimony (45-56 %), and cesium (40-47 %) increased significantly post-exposure in non-smokers (in all firefighters and in paired samples), whose urinary concentrations were generally more impacted by wildfire emissions than those of smokers. Arsenic (80 %) displayed the only significant increase post-exposure in smokers, being the best discriminant of exposure to wildfire emissions in these subjects. Significant positive correlations were found for age and/or career length with cadmium, lead, barium, strontium, and mercury, and for body mass index with arsenic. The reference/guidance values were exceeded for arsenic, zinc, cesium, nickel, antimony, cadmium, lead, thallium, mercury, copper, and cobalt in 1-90 % of firefighters suggesting augmented health risks due to wildfire combating and emphasizing the need of mitigation strategies. This study also provides biomonitoring data to help setting reference values for the occupationally exposed part of population., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Aim: The aim of this study was to evaluate the occupational radiation exposure of staff during endoscopic retrograde cholangiopancreatography (ERCP), with a focus on individuals closest to the radiation source, and to identify potential increases in exposure to hands and eye lenses. Patient radiation exposure during ERCP was also assessed., Materials and Methods: Staff organ doses were monitored using a Philips Allura Xper FD 20 fluoroscopy system, during 24 ERCP procedures for a period of 7 months. Staff doses were measured using thermoluminescence dosemeters and electronic personal dosemeters, and patient effective doses were simulated and calculated., Results: Physicians' annual organ doses ranged from 0.2 to 1.6 mSv for shoulders, 0.1 to 0.4 mSv for eye lenses, and 0.3 to 1.6 mSv for fingers. The annual organ dose of the nursing staff ranged from 0.08 to 2.4 mSv for shoulders, 0.02 to 2.3 mSv for eye lenses, and 1.2 to 5.3 mSv for fingers. The effective dose to patients ranged from 0.009 to 0.46 mSv., Conclusion: Staff doses were within safe limits, but patient doses were high, emphasizing the need for improved radiation protection., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Electromagnetic compatibility testing plays an important role in the type testing of radiation protection dosemeters in view of technical developments and the associated increase in electromagnetic fields. Lately, the use of inductive charging devices has grown as a user-friendly type of charging mobile-phones. In this article, we investigate their impact on active personal dosemeters (APD). The measurements show a substantial additional dose reading of up to several tens of mSv when exposed to the field of an inductive charger for 20 s. According to the widely used Qi standard, the charging devices operate at frequencies of between 87 kHz and 205 kHz for power transfers between 5 W and 30 W. These parameters fall outside the scope of type-testing standards for APD. An update of the standards might therefore be necessary., (Creative Commons Attribution license.)

Previous studies have observed the use of complex industrial chemicals in beauty products. However, occupational exposure of beauty practitioners to various chemicals has not been sufficiently assessed. Our study recruited 37 female nail technicians from 28 nail salons in South China and investigated the abundances and profiles of more than 60 industrial chemicals or their metabolites in indoor dust, hand wipes, and urine of nail technicians. Thirty female college students were also recruited for comparison. The results revealed broad exposure of nail technicians to 42 target chemicals or their metabolites, with mono-phthalate esters (mono-PAEs) exhibiting the highest concentrations (median 284 ng/mL), followed by parabens (median 57.9 ng/mL) and antioxidants (median 19.6 ng/mL) in urine. The urinary concentrations of mono-PAEs, parabens, triclosan (TCS) and triclocarban of nail technicians were significantly higher than those of college students. Pre-shift and post-shift urine did not exhibit significant differences for most chemicals, likely reflecting continuous and long-term exposure. Hand wipe levels of TCS and 2,6-di-tert-butyl-4-methylpheno were significantly associated with urinary levels of these chemicals or their metabolites, while such a pattern was not observed between dust and urinary levels. This highlights the influence of dermal contact or hand-to-mouth transfer on the intake of these chemicals. Collectively, our pilot study demonstrates the occupational exposure of nail technicians to industrial chemicals in beauty products and calls for vigilant self-protection measures to mitigate exposure risks in beauty practitioners., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Cyclic methylsiloxanes (CMSs), widely found in wastewater treatment plants (WWTPs), are potentially hazardous to the environment and human health. In this study, the environmental behavior and human exposure risks of three CMSs (D4-D6) were evaluated in WWTPs located in Beijing and Kunming, Yunnan province. D5 had the highest concentrations in air, water, and sludge, with seasonal variation that consisted of a high concentration in summer and low concentration in winter. The CMS concentrations in air were 3-4-fold higher in the A 2 /O (Anaerobic-Anoxic-Oxic) treatment units than in the other units. CMS emissions to air, soil, and water from the Beijing WWTP were in the ranges of 3.4 × 10 4 -5.0 × 10 4  kg·a -1 , 4.5 × 10 2 -7.5 × 10 2  kg·a -1 , and 2.5 × 10 2 -2.9 × 10 2  kg·a -1 , constituting 98 %, 1.3 %, and 0.7 % of the total emissions, respectively. Total daily inhalation exposure doses of CMSs (ADD inh,CMSs ) associated with four different jobs in WWTPs showed that wastewater treatment technicians had the highest ADD inh,CMSs (51 μg/kg/day), indicating that these people had the highest occupational exposure risk in WWTPs. Therefore, this study identified that atmospheric emission was the main environmental fate of CMSs in WWTPs, and provide a basis for the improvement of WWTP process and risk management decisions. ENVIRONMENTAL IMPLICATION: Assessing the environmental fate and occupational exposure risk of cyclic methylsiloxanes (CMSs) found in wastewater treatment plants (WWTPs) is crucial. This is the first study to identify that atmospheric emission was the main environmental fate of CMSs in WWTPs, especially D5; the inhalation exposure doses of CMSs were all significantly higher in the occupational population working in WWTPs. The results described in our study will help enhance the understanding of current knowledge base of environmental fate and exposure risk of CMSs in WWTPs, and provide a basis for the improvement of WWTP process and risk management decisions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The International Commission on Radiological Protection recommended a significant reduction of the equivalent dose limit for the eye lens. Reportedly, medical staff in charge of diagnostic imaging procedures may exceed the new dose limits for the eye lens. The use of dosimeters dedicated to the eye lens remains low, and dosimeters for the neck region were often used to assess eye lens doses. However, measurements by neck badges may overestimate or underestimate the recommended eye lens doses because the height of the neck differs from that of the eye. This study aimed to evaluate the air dose distribution in the vertical plane to understand the difference between neck and eye doses. H*(10) in the height of the eye position was 52.8% lower than that in the height of the neck position in the under-table position. Thus, the equivalent eye lens dose evaluated using a neck badge dosimeter may be overestimated., (© The Author(s) 2024. Published by Oxford University Press.)

This paper summarises key findings of United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2020/2021 Report on the evaluations of medical and occupational exposures to ionising radiation. Medical exposure remains by far the largest human-made source of radiation exposure of the population. In the period 2009-18, about 4.2 billion medical radiological examinations were performed annually, resulting in an effective dose per caput of 0.57 mSv. The worldwide annual number of workers exposed to natural and human-made sources of ionising radiation is estimated to be ~24 million in the period 2010-14. About 52% of those were employed in the sectors that involve exposure to natural sources of radiation. The annual effective dose was estimated to be around 2.0 mSv for workers exposed to natural sources (excluding radon exposure in workplaces other than mines) and 0.5 mSv for workers exposed to human-made sources. It is important to motivate United Nations Member States to fully participate in UNSCEAR's global surveys on radiation exposure. Future surveys will be relevant and useful and adapted to changing data sources and uses of radiation across the world., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

To become registered radiation worker as radiographer, nuclear medicine (NM) technologist, or radiotherapist in Australian health system, a 4-y bachelor's degree, or a 2-y master's degree in medical imaging (MI), NM, or radiation therapy (RT) approved by the Australian Health Practitioner Regulation Agency is required. During their supervised clinical practice period, it is crucial to monitor students' occupational radiation dose as their annual dose limit is 1 mSv y-1 unlike regular occupational dose of 20 mSv y-1. In this study, the distribution and trend of occupational dose among over 300 radiography, NM, and radiotherapy student practitioners per year in an Australian university are analyzed over a period of 10 y (2013-22). The overall average annual effective dose was well below the dose limit set for the students. Among the three streams-MI, NM, and RT-NM students had the highest annual dose., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Workplace hazards are produced in the process of quarrying stones and include heavy metals like Lead, Cadmium, Nickel, etc. These hazards are harmful to the workers whenever they accumulate above the maximum permissible level in the quarries., Objectives: This study assessed the Lead level in dust samples and housekeeping practices in stone quarries in Gusau., Methods: A cross-sectional study was conducted among 307 quarry workers in Gusau between July and August 2022. The respondents were selected by a two-stage sampling technique. Data was collected using an interviewer-administered questionnaire (ODK). Heavy metal analysis was conducted in the National Research Institute for Chemical Technology Zaria. Data was presented in tables and graphs. Ethical clearance was obtained from the Health Research Ethics Committee of the Ministry of Health Zamfara State., Results: The Lead levels in dust samples in Lalan, Damba, and Samaru quarry work and administrative areas were 0.30, 0.31; 0.09, <0.01; 0.01, 0.04 (mg/kg) respectively [t=0.10, (p=0.92)] and all were below the maximum permissible level (100mg/kg). Only two-thirds, 209 (68.1%) of the respondents take a bath always, about one-third 92 (30.0%) bath sometimes, while six (1.9%) respondents never take a bath before and after work. Almost all the respondents 302 (98.4%) had never used a uniform in the quarry. Only one-sixth, 47 (15.3%) of the respondents avoid food or drink at work areas., Conclusions: This study revealed tolerable levels of lead but poor housekeeping practices in the quarries in Gusau. The quarry employers should ensure periodic training and education of the workers on good housekeeping practices in the quarries., Competing Interests: The Authors declare that no competing interest exists, (Copyright © 2024 by West African Journal of Medicine.)

Objectives: Vascular and interventional radiology procedures are characterized by high exposure of personnel to ionizing radiation. This study assessed the exposure of medical personnel to ionizing radiation during vascular radiology and mechanical thrombectomy procedures., Material and Methods: During vascular radiology procedures, the exposure of 4 groups of workers participating in the procedures was analyzed, i.e., the main operating physician, an assistant physician, a sterile nurse, and a nurse. Measurements of exposure to ionizing radiation were performed using thermoluminescent dosimetry., Results: The registered effective dose during 1 treatment in individual groups is, respectively: mean (M) ± standard deviation (SD) 75±15 μSv, 24±5 μSv, 13±3 μSv, and 8±2 μSv. During mechanical thrombectomy, the operating physician receives an effective dose of M±SD 9±2 μSv. The equivalent doses for the lenses for the operating physician and the doctor assisting during vascular radiology procedures are M±SD 1419±285 μSv and 987±198 μSv, respectively, and for the hands, including the left and right hands, M±SD 4605±930 μSv, 1420±284 μSv, 1898±380 μSv, 1371±274 μSv., Conclusions: If the principles of optimizing radiological protection are not applied during vascular radiology procedures, the permissible dose limits and operational limits equivalent to doses to lenses and hands may be exceeded. Exposure during vascular radiology procedures is comparable to exposure during nuclear medicine procedures in terms of the use of glucose labeled with radioactive fluorine. Int J Occup Med Environ Health. 2024;37(4):403-10., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Given the convenience of using plastics, addressing the growing concerns about their hazardous health effects is imperative. Consequently, a comprehensive risk assessment is necessary to gauge the potential harm microplastics pose. With its urgent call to action, this study aimed to investigate the indoor source and abundance of microplastics in private dental units during routine professional activities. The current analyzed microplastic quantity variations based on morphological characteristics, seasonal fluctuations and polymer-types. The polymer hazard index (PHI) was calculated to evaluate the significant human health risks posed to dental professionals by inhalation of microplastics. Dust samples were collected using a clean brush and steel pan from various flat and horizontal surfaces within each dental unit. The study found that clinical dental units had fewer microplastics (587 ± 184.9 MPs/g/day) than teaching hospitals (1083.80 ± 133.7MPs/g/day), with comparatively more abundance in winter (31 %). ATR-FTIR analysis determined polyethylene terephthalate to be a more abundant polymer (39 %). This study also found an average inhalation microplastic intake risk of 20.23 MP/g/day and 5259.85 MP/g/year for clinical and 29.45 MP/g/day and 765.12 MP/g/year for teaching hospital dental units. Female dental professionals have 1.1 times more microplastic inhalation risks than male dental professionals. According to PHI findings, overall minor to medium polymer risk was determined. In conclusion, this evidence-based research underscores the urgent need for a shift towards more sustainable practices in the dental healthcare sector. Dental professionals should prioritize using non-plastic material protective equipment and a proper ventilation system to reduce exposure to these particles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: The research investigates the occupational eye lens dose of interventional cardiologists and examines several methodologies for measuring eye lens doses, including direct methods using Hp(3) dosimeters and indirect methods using surrogate dosimeters. Moreover, the study scrutinizes factors impacting the evaluation of eye lens dose, making a substantial contribution to the field within Sri Lanka., Methodology: Twelve interventional cardiologists underwent monitoring for eye lens doses utilizing both direct (Hp(3)) and indirect (Hp(10) and Hp(0.07)) measurements. Annual equivalent occupational eye lens doses were computed for each practitioner, and an analysis was carried out to compare direct and surrogate dosimeter readings, examining over/underestimation. Additionally, the research explored factors influencing eye lens doses among cardiologists., Results: This study highlighted a critical need for enhanced protective measures, particularly due to the highest annual occupational equivalent eye lens dose recorded at 34 ± 4.1 mSv exceeding the annual dose limit. The study revealed robust correlations (R 2 =0.99) between direct readings and surrogate dosimeters. However, the indirect measurements marginally underestimated the direct Hp(3) dose values. Factors such as patient Body Mass Index, Air Kerma, Dose Area Product, Fluoroscopy Time, and operator height significantly impacted eye lens dose (p<0.0001). However, years of experience exhibited no significant association with eye lens dose among operators., Conclusion: This study emphasized the pivotal role in evaluating equivalent eye lens doses for interventional cardiologists in Sri Lanka, along with the viability of indirect measurements in estimating Hp(3) eye lens radiation doses in the absence of dedicated eye dosimeters., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Associazione Italiana di Fisica Medica e Sanitaria. Published by Elsevier Ltd. All rights reserved.)

Polycylic Aromatic Hydrocarbons (PAHs) are produced during the incomplete burning of organic materials. PAH sources include vehicle exhaust, tobacco smoke and waste incineration. Environmental and occupational exposures to PAHs are known to occur. Cancer is a significant endpoint of PAH exposure and several occupations associated with high PAH exposure have been classified by IARC as carcinogenic to humans (Group 1). Pyrene is a common component of PAH mixtures and metabolism of pyrene leads to the excretion of 1-hydroxypyrene glucuronide (1-OHPyrG) in urine. Laboratory measurement of urinary 1-OHPyrG is employed in occupational and environmental biomonitoring programmes. The production of an anti-1-OHPyrG monoclonal antibody would allow the development of a PAH biomonitoring ELISA facilitating large scale laboratory screening and routine testing. The development of a lateral flow immunoassay and the production of a field test (point of use test) would greatly increase the value of biomonitoring. A novel Lateral Flow has been developed which employs an anti-1-OHPyrG sheep monoclonal antibody (Mab) to capture the PAH metabolite. The captured metabolite is visualised through a second Mab raised against the Mab-1-OHPyrG immune complex. This sandwich assay provides a positive correlation between the assay signal and biomarker concentration. A Smartphone camera allows signal measurement and a carefully considered 'app' provides result interpretation and data analysis. Results are provided in an exposed/not-exposed format. Performance of the lateral flow was confirmed through a comparative study and field trial. The development of a lateral flow test provides "real-time" analysis to occupational health professionals. On-site screening allows the immediate confirmation of safe working practice, provides immediate reassurance to those involved in potentially hazardous activities and greatly increases the efficacy of biomonitoring., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lathan Ball reports financial support was provided by Bioventix plc. Lathan Ball reports a relationship with Bioventix plc that includes: consulting or advisory and travel reimbursement. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2024 Elsevier B.V. All rights reserved.)

Overexposure of sewage workers to bioaerosol released from wastewater treatment plants (WWTPs) can cause serious infections, but practical method for controlling their health risk is lacking. In this study, reverse quantitative microbial risk assessment was used to estimate the daily critical exposure time (CET) of sewage workers exposing to Staphylococcus aureus bioaerosol emitted by three emission sources facilities in a WWTP based on either U.S. EPA or WHO benchmark, and sensitivity analysis was conducted to analyze the influence of various parameters on the outcomes of CET. The results showed that the CET of females was always 1.12-1.29 times that of males. In addition, the CET after wearing face masks was 28.28-52.37 times as long as before. The working time can be determined based on the CET results of male workers wearing face masks exposed to the inverted-umbrella aeration tank (14.73-550.98 min for U.S. EPA benchmark and 55.07-1972.24 min for WHO benchmark). In each scenario, the variable parameter exposure concentration (ec) always showed the most influence on the CET results. After wearing the face masks, the removal fraction by employing face masks also had a significant effect on the results, only second to ec. Therefore, the wearing of face mask is the most convenient and effective measure to prolong the CET. Furthermore, practical methods to reducing bioaerosol concentration in WWTPs exposure are also necessary to extend CET and safeguard worker health. This study enriches the application range of reverse quantitative microbial risk assessment framework and provides theoretical support for stakeholders to establish reasonable working time threshold guidelines, and practical method and novel perspective to protect the on-site health risks of sewage workers exposing to various facilities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: This study has been aimed to investigate factors associated with elevated blood lead levels (BLLs) across different percentiles in individuals employed in the petroleum industry and residents of Kirkuk City . In addition, to provide evidence-based approaches to mitigate exposure risks and safeguard vulnerable populations., Methods: The study involved 357 participants and utilized quantile regression to examine BLL in petroleum industry workers and Kirkuk residents., Results: Median BLLs were higher among workers (17.5 μg/dL) compared to residents in the city (9.9 μg/dL) and suburbs (7.4 μg/dL). Factors such as smoking, outdoor work, and lower education were associated with elevated BLLs, as confirmed by quantile regression., Conclusions: This study found higher BLLs in petroleum workers compared to Kirkuk residents, associated with smoking, outdoor work, and lower education. The results emphasize the need for targeted interventions and policies to mitigate lead exposure risks in this industrial region., Competing Interests: Conflict of interest: None declared., (Copyright © 2024 American College of Occupational and Environmental Medicine.)

Objective: The aim of the study is to explore the feasibility of using nonvibration-exposed organ-related indices as vibration-induced white finger (VWF) diagnostic biomarkers., Methods: Individuals were selected from a factory in China using the judgment sampling method. They were divided into control (con), non-VWF, and VWF groups according to the presence/absence of exposure to hand-transmitted vibration and VWF. Blood samples were collected for ELISA tests., Results: Analysis of receiver operating characteristic curves was done on six indicators to assess their diagnostic sensitivity for VWF. Area under the receiver operating characteristic curve for insulin was 0.909 and was 0.923 for aspartate aminotransferase., Conclusions: Insulin and aspartate aminotransferase could be used as indices for the diagnosis of hand-arm vibration syndrome., Competing Interests: Yang, Zhou, F. Zeng, Wu, Y. Zeng, and Chen have no relationships/conditions/circumstances that present potential conflict of interest., (Copyright © 2024 American College of Occupational and Environmental Medicine.)

Purpose: Excessive paper dust during paper production may harm the workers' respiratory health. We wanted to assess the inhalable paper dust levels and its determinants among paper industry workers., Methods: A study was conducted in Ethiopia to assess the level of personal inhalable paper dust exposure among four paper mills. A total of 150 samples were collected using the IOM sampler attached to Side Kick Casella pumps at a flow rate of 2 L/min. The samples were analyzed in Nemko Norlab, Norway. Linear mixed-effect models were applied to identify determinants of inhalable paper dust., Results: The geometric mean of personal inhalable paper dust was 3.3 mg/m 3 with 80% of the measurements exceeding the Swedish occupational exposure limit (OEL) of 2 mg/m 3 . The linear mixed-effects model showed that the level of dust was 28% higher when using high-speed than when using low-speed rewinding machines, while paper mills with an average of more than four machines per job group had 22% higher exposure than paper mills with a lower number of machines. Furthermore, working in packing and preparation was associated with higher dust exposure than in other areas., Conclusions: The dust exposure levels were above the Swedish OEL for 80% of the samples. This indicates that preventive measures should be established in the industry. The exposure model identified high-speed rewinding machines, a high number of machines, and work in preparation and packing as associated with high levels of paper dust exposure., Competing Interests: Declarations Ethical approval Ethical clearance was obtained from the Institutional Review Board of the College of Health Science Addis Ababa University number 079/22/SPH and from the Regional Committee for Research Ethics South East Norway, number 2022/521268. After the purpose and the importance of their participation were explained informed consent was taken from each study participant. Privacy and confidentiality of information given by each participant were kept properly and personal identifiers were removed. Conflict of interest The authors declare that they have no competing interests., (© 2024. The Author(s).)

To investigate the mediating effect of oxidative stress on the relationships between low-concentration benzene, toluene, and xylene (BTX) exposure and blood pressure in workers. A cross-sectional study involving 841 workers from a petroleum refining enterprise in Hainan, China, was conducted. Among the workers, 615 workers were exposed to low-concentration BTX, and 216 workers were in the control group. S-phenylmercapturic acid (S-PMA), hippuric acid (HA), and methyl hippuric acid (MHA, including the three isomers 2-MHA, 3-MHA, and 4-MHA) were measured in the urine of workers via high-performance liquid chromatography‒tandem triple quadrupole mass spectrometry to assess the internal BTX burden. Oxidative stress markers, blood pressure, and their correlations were analysed in both the exposed and control groups of workers. Mediation analysis was used to investigate the potential role of oxidative stress in the relationship between BTX exposure and blood pressure. The concentrations of BTX at the sampling points in the enterprise were all below the limits stipulated in China's national occupational health criteria: occupational exposure limits for hazardous agents. With respect to the internal burden of BTX, the concentrations of the benzene metabolite S-PMA, the toluene metabolite HA, and the xylene metabolites 3-MHA and 4-MHA in the urine samples in the exposure group were greater than those in the control group (P < 0.05). The correlation analysis results revealed that the concentration of the benzene metabolite S-PMA in workers' urine was positively correlated with diastolic blood pressure (DBP) (r = 0.265, P < 0.05). Compared with those in the control group, DBP was greater (β = 1.363, 95% CI 0.088 -2.639), serum superoxide dismutase (SOD) activity was lower (β = - 0.037, 95% CI - 0.060 to - 0.013), and the serum malondialdehyde (MDA) concentration was greater (β = 0.066, 95% CI 0.022-0.110) in the exposure group. Partial correlation analysis revealed a positive correlation between DBP and MDA (r s = 0.115, P < 0.01). The results of the mediation analysis indicated that MDA was a complete mediator between low BTX exposure and DBP (P < 0.05). Occupational exposure to low concentrations of BTX elevates blood pressure and oxidative stress among workers. A positive correlation between DBP and MDA was observed, with MDA acting as a complete mediator between low-concentration BTX exposure and DBP elevation., (© 2024. The Author(s).)

Heavy metal contamination from occupational sources is a cause for concern due to its potential accumulation in the environment and the body of living organisms, which leads to long-term toxic effects. There is limited evidence on the concentration of heavy metals in the body fluids of welding workers. This study aimed to measure the concentration of nickel (Ni) and chromium (Cr) as two main toxic heavy metals in the urine samples of welders and determine the potential relationship of various environmental factors on their concentration levels. This study was conducted in Iran in 2022-2023. Eighty-five urine samples were collected from the studied welding workers. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of Ni and Cr. Data related to socio-demographic characteristics (education level, income, work experience, age, and body mass index (BMI)), lifestyle profile (consumption of seafood and canned food, smoking, physical activity), type of ventilation and preventive devices at work, and suffering from underlying diseases (cardiovascular and high blood pressure) were collected using valid questionnaires. Ni and Cr were present in 100% of urine samples with mean concentrations of (1.09 ± 0.294) and (11.45 ± 16.751) µg/g creatinine, respectively. A significant correlation was observed between the mean concentration of Ni and Cr with the level of education, income, work experience, age, consumption of seafood and canned food, smoking, type of ventilation and preventive devices, and underlying diseases (p-value < 0.05). Also, there was no significant difference between Ni concentration and physical activity and Cr concentration with BMI. Lifestyle determinants and not using preventive devices are important predictors of urinary heavy metals in welding workers. Therefore, more research is required to determine the adverse effects of long-term exposure to these heavy metals., (© 2024. The Author(s).)

A toxicokinetic model of the pyrethroid insecticide lambda-cyhalothrin (LCT) was developed to relate absorbed doses to urinary cis-3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylic acid (CFMP) metabolite levels used as a biomarker of exposure. The model then served to reconstruct absorbed doses in agricultural workers and their probability of exceeding the EFSA Acceptable occupational Exposure Level (AOEL). The toxicokinetic model was able to reproduce the temporal profiles of CFMP in the urine of operators spraying pesticides using the optimized model parameters (adjusted to human volunteer data). Modeling also showed that simulation of an inadvertent oral exposure mainly was the exposure scenario giving the best fit to CFMP urinary time-course data in applicators. With the dermal model parameters optimized from data in volunteers, simulation of a dermal exposure in applicators did not allow to reproduce the observed peak excretions and urinary metabolite levels; extremely high applied dermal doses would be required but still simulated dermal penetration rate would remain too slow. Simulation of an inhalation exposure allowed to reproduce the observed time-courses, but with unrealistic air concentrations. For applicators with the highest urinary concentrations, there was a probability of exceeding the AOEL at some points during the biomonitoring period [>50% probability of exceeding for 27% of 24-h samples]; for non-applicator workers the probability of exceeding the AOEL value was very low [corresponding value of 5%]. Furthermore, the median [95% CI] estimates of 10 000 Monte Carlo simulations led to a biological reference value corresponding to the AOEL of 116 [113-119] ng/kg bw/d and 7.5 [7.3-7.7] μg/L. Overall, 7% of applicators and 1% of workers performing weeding and strawberry picking had a probability of exceeding this biological reference value. As a next step, it would be interesting to apply these methods to multiple exposure to various contaminants., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Côté, Bouchard. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: A hospital-based cross-sectional case-control study was conducted to investigate the association between exposure through various pesticide residues detected in the plasma and serum 8-OHdG levels among farmers and non-farmers diagnosed with leukaemia, lymphoma and breast cancers and compare the same with healthy controls with no cancer and no exposure., Methodology: The present study was conducted among the farmers and non-farmers visiting a regional tertiary cancer care hospital in Hyderabad, Telangana State, India. Data were collected by administering a pre-tested questionnaire through an interview followed by the collection of blood samples which were analyzed for pesticide residues using LC-MS/MS while the serum levels of 8-OHdG were measured using ELISA. Data were analyzed using SPSS 24., Results: The pesticide residues detected were chlorpyrifos, dimethoate, malathion, phosalone, and quinalphos which were approved and recommended for their use on the crops that were cultivated by the farmers in their plasma samples along with banned pesticide residues like monocrotophos, diazinon, and dichlorvos among farmers diagnosed with all three types of cancers while the non-farmers and healthy controls were not detected with any such residues. In addition, farmers diagnosed with leukemia had higher levels of all the pesticide residues in their plasma than those diagnosed with lymphoma and breast cancers. Further, a significant difference was also observed between profenofos residues in plasma and serum 8-OHdG levels., Conclusion: In the present study, though the farmers diagnosed with three types of cancers were detected with various types of pesticide residues analysed, only residues of profenofos showed a significant difference with serum levels of 8-OHdG suggesting the need for an in-depth follow up molecular studies in a larger cohort to assess the possible association between 8-OHdG levels with the pesticide residues among the exposed., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Pandiyan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: To evaluate the risk of major chemical exposure positions in copper and nickel smelting enterprises, and provide a basis for risk assessment and prevention control measures. Methods: From September to October 2023, two copper nickel ore smelting enterprises in Xinjiang Uygur Autonomous Region were selected as the research objects. Relevant information on chemicals was collected through occupational hazard field investigations. Qualitative analysis and exposure index methods were used in GBZ/T 298-2017 "Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazardous Factors in the Workplace" to conduct risk assessments on the main chemical exposure positions. The qualitative risk assessment results were checked for consistency using the Weighted Kappa coefficient. Results: The positions with high risk of exposure to hazardous chemicals in copper nickel smelting enterprises are saponification positions exposed to hydrochloric acid in refining processes, black nickel positions exposed to sodium hydroxide, and tail suction positions. The consistency between the two occupational health risk assessment results is poor (Kappa=0.14) . Conclusion: The amount of major hazardous chemicals in copper-nickel smelting enterprises is large, and the occupational health risks caused by exposure are complex and diverse, so the effects of chronic occupational health should be strengthened.

Objective: To analyze and understand the level of occupational external radiation personal dose of radiation workers in a hospital, and provide a reference for radiation protection. Methods: In May 2023, the personal dose monitoring data of all radiation workers in the hospital from 2018 to 2022 were collected, and their occupational external radiation exposure levels were analyzed and evaluated. All radiation workers were divided into radiation diagnosis, radiotherapy, interventional radiology, and nuclear medicine according to their occupational categories. Results: A total of 1626 person-times were monitored from 2018 to 2022, and the average annual effective dose per person (0.13-0.36 mSV) was lower than the national limit of 20 mSv. The average annual dose of nuclear medicine was the highest (0.36 mSv), and interventional radiology was lower (0.13 mSv). The average annual dose of individuals was the highest in 2020 (0.24 mSv) . Conclusion: The average annual effective dose per person of radiation workers in this hospital is lower than the national standard, and it is still necessary to strengthen the inspection of the wearing of personal dosimeters and the using of protective equipment for radiation workers.

The International Commission on Radiological Protection (ICRP) has developed the reference Human Respiratory Tract Model (HRTM), detailed in ICRP Publications 66 and 130, to estimate the deposition and clearance of inhaled radionuclides. These models utilize reference anatomical and physiological parameters for particle deposition (PD). Biokinetic models further estimate retention and excretion of internalized particulates, aiding the derivation of inhalation dose coefficients (DC). This study aimed to assess variability in deterministic 131 I biokinetic and dosimetry models through stochastic analysis using the updated HRTM from ICRP Publication 130. The complexities of the ICRP PD model were reconstructed into a new, independent computational model. Comparison with reference data for total PD fractions for reference worker, solely a nose breather, covering activity median aerodynamic diameters from 0.3 μ m to 20 μ m, showed a 1.04% relative and 0.7% absolute difference, demonstrating good agreement with ICRP deposition fractions. The deterministic DC module was reconstructed in Python and expanded for stochastic analysis, systematically expanding deposition components from HRTM and assigning probability distribution functions to uncertain parameters. These were integrated into an in-house stochastic radiological exposure dose calculator, utilizing latin hypercube sampling. A case of an occupational radionuclide intake was explored, in which biodistribution and committed effective DC (CEDC) were computed for 131 I type F, considering a lognormal particle size distribution with a median of 5 μ m. Results showed the published ICRP reference CEDC marginally exceeds the 75th percentile of observed samples, with log-gamma distribution as the best-fit probability distribution. A Random Forest regression model with SHapley Additive exPlanations was employed for sensitivity analysis to predict feature importance. The analysis identified the HRTM particle transport rates scaling factor, followed by the aerodynamic deposition efficiency in the alveolar interstitial region as the most impactful parameters. This study offers a unique stochastic approach on inhaled particulate metabolism, enhancing radiation consequence management, medical countermeasures, and dose reconstruction for epidemiological studies., (Creative Commons Attribution license.)

In order to understand the organophosphate flame retardants (OPFRs) pollution and evaluate the inhalation exposure risk in formal e-waste recycling facilities, the air concentrations, particle size distribution and gas-particle partitioning of OPFRs in four typical workshops were investigated. The total Σ 15 OPFR concentrations inside workshops were in the range of 64.7-682 ng/m 3 , with 5.80-23.4 ng/m 3 in gas phase and 58.8-658 ng/m 3 in particle phase. Triphenyl phosphate (TPHP) and tris(2-chloroisopropyl) phosphate (TCIPP) were main analogs, both of which contributed to 49.0-85.7% of total OPFRs. In the waste printed circuit boards thermal treatment workshop, the OPFRs concentration was the highest, and particle-bound OPFRs mainly distributed in 0.7-1.1 μm particles. The proportions of TPHP in different size particles increased as the decrease of particle size, while TCIPP presented an opposite trend. The gas-particle partitioning of OPFR analogs was dominated by absorption process, and did not reach equilibrium state due to continuous emission of OPFRs from the recycling activities. The deposition fluxes of OPFRs in respiratory tract were 65.7-639 ng/h, and the estimated daily intake doses of OPFRs were 8.52-76.9 ng/(kg·day) in four workshops. Inhalation exposure was an important exposure pathway for e-waste recycling workers, and deposition fluxes of size-segregated OPFRs were mainly in head airways region., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Jie Guo reports financial support was provided by National Natural Science Foundation of China. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Comprehensive volatile organic compounds (VOCs) emission control is imperative to decreasing occupational health risks and environmental impact of the packaging and printing industries. In this work, we investigated the VOCs emission characteristics and concentrations of individual contaminants generated by the packaging and printing industries, with regard to various categories, processes, and geographic regions. VOCs emissions, ozone formation potential (OFP), and associated health risks were assessed at 10 representative packaging and printing firms across several cities in Shandong Province, China. Plastic packaging enterprises had the greatest levels of unorganized VOCs emissions, consisting predominantly of oxygenated volatile organic compounds (OVOCs), followed by alkanes and halocarbons. From metal and paper packaging enterprises, OVOCs, alkanes, and aromatics were significant components of unorganized VOCs emissions. Aromatics, halocarbons, and OVOCs contributed significantly to OFP in workshops. The potential carcinogenic risk associated with VOCs in the packaging and printing industries was not significant. However, according to the findings in this study, the workshop environment may provide a comparatively elevated non-carcinogenic risk attributable to ethyl acetate, isopropanol, acrolein, 1,1,2-Trichloroethane, 1,2-Dichloropropane, and naphthalene exposure. In particular, the endocrine-disrupting and genetic toxic effects caused by benzene, toluene, styrene, and naphthalene should not be overlooked. Thus, it is essential to provide precedence to the working environment conditions of workshop laborers, while also undertaking scientific and systematic measures to mitigate the detrimental impacts of VOCs on the environment and human welfare., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The presence of BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) compounds in beauty salons has raised concerns about potential health risks. This study aimed to measure the levels of BTEX compounds in the air of beauty salons in Lahijan, Iran and assess the associated health risks. Air samples were collected from 15 beauty salons, and the concentrations of BTEX compounds were measured according to 1501 NIOSH standard method. The results showed that the mean concentrations of benzene (20.62 µg/m 3 ), toluene (18.3 µg/m 3 ), ethylbenzene (38.36 µg/m 3 ), and O and P-xylene (27.35, 23.6 µg/m 3 ) were above the recommended levels. The indoor to outdoor ratios for benzene, toluene, ethylbenzene, O and P-xylene were 3.04, 2.36, 3.75, 4.89, and 6.54, respectively. Also, the toluene/benzene (T/B) ratio in indoor and outdoor was 20.9 and 2.68 respectively. Almost half of the technicians (49.12%) reported adverse health effects, including joint pain, itchy eyes and nose, and respiratory allergies. The IARC guideline suggests that there is a potential risk of cancer development for individuals in all salons with LCR values exceeding 10 -6 , but the HQ index values indicate no non-carcinogenic risk. The findings suggest that beauty salon workers and customers are at risk of developing health problems from exposure to BTEX compounds. Effective risk management strategies, such as proper ventilation, use of personal protective equipment, and substitution of harmful chemicals with safer alternatives, to minimize exposure and protect the health of salon workers and customers recommended., (© 2024. The Author(s).)

According to NASA's plans, a human travel to the Moon is planned by the end of 2025 with the Artemis II mission, and humans should land on the Moon again in 2026. Exposure to space radiation is one of the main risks for the crew members; while for these short missions the doses from galactic cosmic rays would be relatively low, the possible occurrence of an intense solar particle event (SPE) represents a major concern, especially considering that in 2025 the Sun activity will be at its peak. Quantifying the amount and the effects of such exposure is therefore crucial, to identify shielding conditions that allow respecting the dose limits established by the various space agencies. By exploiting an interface between the BIANCA biophysical model and the FLUKA Monte Carlo radiation transport code, in this work we implemented a male and a female voxel phantom and we calculated absorbed doses and Gy-Eq doses in the various tissues/organs, as well as effective doses, following exposure to the August 1972 SPE, the most intense event of the modern era. The calculations were performed respect the organ dose limits for 30 d missions. A detailed comparison between male and female doses was then carried out, also considering that the Artemis II crew will include a woman. The results showed that female doses tend to be higher than male doses, especially with light shielding. This should be taken into account in mission design, also considering that, in a typical lunar mission, up to 15% of time may be spent in extra-vehicular activities, and thus with light shielding. More generally, this work outlines the importance of performing separate calculations for male and female astronauts when dealing with radiation doses and effects., (Creative Commons Attribution license.)

Rodent inhalation studies indicate styrene is a mouse lung-specific carcinogen. Mode-of-action (MOA) analyses indicate that the lung tumors cannot be excluded as weakly quantitatively relevant to humans due to shared oxidative metabolites detected in rodents and humans. However, styrene also is not genotoxic following in vivo dosing. The objective of this review was to characterize occupational and general population cancer risks by conservatively assuming mouse lung tumors were relevant to humans but operating by a non-genotoxic MOA. Inhalation cancer values reference concentrations for respective occupational and general population exposures (RfC car-occup and RfC car-genpop ) were derived from initial benchmark dose (BMD) modeling of mouse inhalation tumor dose-response data. An overall lowest BMDL 10 of 4.7 ppm was modeled for lung tumors, which was further duration- and dose-adjusted by physiologically based pharmacokinetic (PBPK) modeling to derive RfC car-occup/genpop values of 6.2 ppm and 0.8 ppm, respectively. With the exception of open-mold fiber reinforced composite workers not using personal protective equipment (PPE), the RfC car-occup/genpop values are greater than typical occupational and general population human exposures, thus indicating styrene exposures represent a low potential for human lung cancer risk. Consistent with this conclusion, a review of styrene occupational epidemiology did not support a conclusion of an association between styrene exposure and lung cancer occurrence, and further supports a conclusion that the conservatively derived RfC car-occup is lung cancer protective.

Background: In Brazil, gas stations are not self-service; attendants fill fuel tanks, leading to chronic exposure to BTEX (benzene, toluene, ethylbenzene, and xylenes), which can cause bone marrow degeneration and immunosuppression. This systematic review highlights recent advances in biomonitoring gas station workers (GSW)., Methods: We searched PubMed, Medline, and Cochrane databases for articles in English, French, Portuguese, and Spanish from 2014 to April 30, 2024, using multiple search terms., Results: A total of 1,086 articles were identified, 322 were analyzed, and 13 were included in the final review. We highlighted recent technologies in GSW biomonitoring, such as immunophenotyping, molecular cytogenetics (FISH), and measuring miRNAs and inflammatory markers via ELISA. We also explored the link between benzene exposure and immunosuppression and suggested a potential association with chronic inflammation.  Conclusion: GSWs face significant health risks and require continuous clinical monitoring, even in the absence of overt disease. Effect biomarkers may indicate early biological responses to benzene toxicity and highlight potential health risks. However, there is no universally accepted gold standard for assessing these biomarkers.

An occupational health study was conducted inside reinforced-concrete earth-covered munitions storage magazines (ECMs) at Fort Wingate Depot Activity (FWDA), a former military facility near Gallup, New Mexico. A two-phased approach was used: (1) HEPA vacuuming of bulk dust and (2) wipe sample verification post-vacuuming. Site-specific occupational health criteria were derived to evaluate potential risk from inhalation of bulk dust (Phase 1) and dermal contact of residual dust (Phase 2). In Phase 1, no explosives detections exceeded site-specific screening criteria. Any explosives detected, with or without criteria were carried forward into Phase 2. In Phase 2, no exceedances were noted for detected explosives with criterion. Using structure/reactivity characteristics within the explosives category, surrogates were assigned to the six (6) explosives without occupational health screening criteria. Based upon structural similarities within the analysis category, assignments of surrogates to explosives without criteria did not adversely impact the study conclusions. In Phase 1, lead was detected in bulk dust in all 35 igloos and all detections exceeded the applicable criterion for commercial/industrial workers. In Phase 2, all lead detections in wipe samples were below the wipe screening criteria. Study results indicated the ECM interiors posed no unacceptable dermal occupational risk for explosives or lead residues following bulk dust removal. High-efficiency particulate air (HEPA) filter vacuuming of interior bulk dust in ECMs at FWDA reduced occupational risk/hazard for exposure via inhalation and dermal contact for commercial/industrial worker activities under worst-case exposure conditions. Both phases of this sampling design are widely applicable, provided the site-specific assumptions made for this study are evaluated for suitability to another specific application and adjusted if needed.

Exposure to biosolids in human waste handling occupations is associated with a risk for illness due to microbial infections. Although several years of exposure to biosolids might be hypothesized to be a prophylaxis against infection, the risks associated with infections from antibiotic-resistant organisms can also be a potential concern. Therefore, this study aimed to conduct a screening level risk assessment by deriving occupational exposure limits (OELs) characterizing the risks of adverse health effects among workers in human waste handling occupations with a focus on exposure to two pharmaceuticals commonly found in biosolids: ciprofloxacin (CIP) and azithromycin (AZ). Epidemiological and exposure studies of workers exposed to biosolids were identified through searches of major scientific databases. Screening OELs (sOELs) for these antibiotics were derived using a standardized methodology. The airborne concentrations of CIP and AZ antibiotics were determined using an exposure factors approach. The health-based exposure limits (i.e., sOELs) and the acceptable daily exposure (ADE) values for both of these antibiotics were derived as 80 μg/m 3 and 12 μg/kg-day, respectively. An exposure factor approach suggested that inhalation route exposures to CIP and AZ are well below the sOELs and ADE daily doses, and likely too low to cause direct adverse health effects through antibiotic inhalation. A critical review of epidemiological studies on different occupations handling biosolids showed that the workers in industries with potential biosolids exposure have experienced an increased incidence of microbial-exposure-related illness. The health effects seen in the workers have been attributed to bacterial, viral, and protozoan infections. To the extent that bacteria are the pathogen of concern, it is not clear whether these bacteria are resistant to antibiotics commonly found in biosolids. It is also unclear whether the presence of antibiotics or antibiotic-resistant bacteria increases the susceptibility of these workers. Additional studies will provide more definitive estimates of inhalation and dermal exposures to CIP and AZ and could verify the exposure estimates in this study based on the literature and common exposure factors.

Non-medical masks such as disposable non-medical, commercially produced cloth, and homemade masks are not regulated like surgical masks. Their performance, in terms of filtration efficiency and breathability, is variable and unreliable. This research provides a quantitative evaluation of various non-medical masks, assesses their fabrics' potential for the reduction of transmission of bioaerosols such as the SARS-CoV-2 virus, and compares them to surgical masks and N95 filtering facepiece respirators. Using a testing line with a NaCl challenge aerosol, four types of commercial reusable cloth masks, two types of disposable non-medical masks, three types of surgical or N95 masks, and seven types of commonly available materials were tested individually and in combinations. The testing line and procedure were adapted from the ASTM F2299-03: Standard Test Method for Determining the Initial Efficiency of Materials Used in Medical Face Masks to Penetration by Particulates Using Latex Spheres testing method used for testing surgical masks. Filtration efficiencies at 0.15 µm particle diameter at a face velocity of 25 cm/sec for commercial cloth masks, disposable non-medical masks, surgical masks, commercial mask combinations, and homemade combinations ranged from 16-29%, 39-76%, 91-97%, 51-95%, and 45-94%, respectively. The pressure drop results for the different masks and material combinations were all under 3 mm H 2 O/cm 2 except for one material configuration. This study builds on other research that looks at individual materials and masks by testing combinations alongside the individual masks and materials. With proper layering, household materials can achieve the filtration efficiency and low pressure drop requirements of surgical masks. The filtration capabilities of disposable and cloth mask fabrics vary considerably meaning that they are not a reliable or consistent facemask option, regardless of fit.

Exposure to chlorine dioxide by staff working in a gnotobiotic mouse facility at an Australian research institute was measured to determine whether current controls were sufficient to ensure their exposure remains below the current Australian workplace exposure standard. A combination of workplace surveys, interviews with workers, and personal sampling was undertaken to understand the workplace, identify higher-risk tasks, and measure the concentration of chlorine dioxide in the air where the workers conduct routine tasks involving the use of a chlorine dioxide-based disinfectant. Personal sampling utilized the validated Occupational Safety and Health Administration (OSHA) method ID-202, with minor alterations. The tasks identified as being associated with higher airborne exposure to chlorine dioxide were the use of an atomizer to fill isolator ports with aerosolized disinfectant and the use of a disinfectant dunk tank to submerge and surface decontaminate objects. The current work practices in the gnotobiotic facility were found to be compliant with the current 8-hr time-weighted average (TWA) limit of 0.1 ppm (0.28 mg/m 3 ) but were not compliant with the 15-min short-term exposure limit (STEL) of 0.3 ppm (0.83 mg/m 3 ). Improvements in exposure controls, such as implementing the use of a fume cupboard (hood) or other local ventilation when activating the disinfectant solution and improving the utilization of respiratory protective equipment, are therefore required to meet the STEL, but it is recommended that such improvements are also aimed at meeting the proposed Peak limitation of 0.1 ppm that is expected to soon be adopted by Safe Work Australia, replacing the current TWA-8hr and STEL exposure standards.

Wildfires can negatively impact the health and well-being of wildland firefighters through a variety of exposure pathways. Many studies have measured acute health effects from occupational exposure to pollutants in wildfire smoke; however, research specifically examining cancer risks from exposure to carcinogens is limited. This review aimed to better understand cancer risk in this occupation by assessing the existing evidence of exposures and summarizing measured concentrations of carcinogens among wildland firefighters. A systematic search was conducted to identify scientific papers using the following databases: Medline(OVID), Embase(OVID), PsycINFO(OVID), Cochrane Library, CINAHL(EBSCOHost), EconLit(EBSCOHost), Scopus, Agricultural and Environmental Science Collect(ProQuest), and NIOSHTIC-2. Forty-nine papers were identified that met eligibility criteria. Across the papers, 31 carcinogens were identified and quantified using a variety of assessment methods. Papers measured particulate matter ( N  = 26), polycyclic aromatic hydrocarbons ( N  = 12), volatile organic compounds ( N  = 14), crystalline silica ( N  = 5), black carbon ( N  = 4), asbestos ( N  = 3), radionuclides ( N  = 7), and metals ( N  = 2). Most papers measured inhalation exposures through traditional air sampling methods, but a subset of exposures to polycyclic aromatic hydrocarbons ( N  = 8), as well as heavy metals ( N  = 1), were measured through urinary biomarkers and naphthalene was measured using dermal wipe samples ( N  = 2). Although the heterogeneity of exposure assessment methods made direct comparison of concentrations difficult, the papers provide consistent evidence that wildland firefighters are regularly exposed to carcinogens. All wildland fire personnel should continue to implement recommended mitigation strategies and support new mitigations to reduce exposure to carcinogens on the job.

The skin is complex with multiple layers serving protective, regulatory, and detective functions. The skin hosts chemicals originating from consumption, synthesis, and the environment. Skin chemicals can provide insight into one's daily routine or their level of safety in a work environment. The goal of this study was to investigate the utility of noninvasive skin swabs to detect drugs in a pharmacy setting and to determine whether drugs are transferred to the skin of pharmacy staff. To answer this question, skin swabs were collected from healthy pharmacy staff workers and healthy non-pharmacy individuals and analyzed via untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS). Drugs were annotated through library matching against the GNPS community spectral library. We then used questionnaire data to exclude medications that participants took orally or applied topically and focused on the drugs participants were exposed to in the work setting. Overall, pharmacy staff had a higher number and variety of medications on their skin as compared with healthy individuals who did not work in a pharmacy. In addition, we identified some chemicals such as N,N-Diethyl-metatoluamide on a large number of subjects in both experimental and control groups, indicating environmental exposure to this compound may be ubiquitous and long-lasting., (© 2024 The Author(s). Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

The recycling of e-waste can lead to the release of organic chemicals when materials containing additives are subjected to dismantling and grinding. In this context, the exposure of workers from a Catalonian e-waste facility to flame retardants and plasticizers (including organophosphate esters (OPEs), polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs) and dechloranes) was assessed using T-shirts and wristbands as passive samplers. The study area includes an area exclusively dedicated to cathodic ray-tube (CRT) TVs dismantling, and a grinding area where the rest of e-waste is ground. All the families of compounds were detected in both T-shirts and wristbands, with the highest concentration levels corresponding to OPEs, followed by PBDEs, NBFRs, and dechloranes. The CRT area presented higher concentration levels than the grinding area. The compounds with higher concentrations in T-shirts were 2-ethylhexyl diphenyl phosphate (EHDPP), diphenyl cresyl phosphate (DCP) and triphenyl phosphate (TPHP), and the total concentration of all groups ranged between 293 and 8324 ng/dm 2 -h (hour). In the case of the wristbands, the most abundant compounds were DCP, TPHP, and BDE-209, with total concentrations between 188 and 2248 ng/dm 2 -h. The two sampling methods appear to be complementary, as T-shirts collect coarser particles, while wristbands also capture volatile compounds. Based on normalized surface and time concentrations, the estimated daily intake (EDI) through dermal contact was calculated and carcinogenic and non-carcinogenic risks (CR and non-CR) associated with this activity assessed. The results show median CR 29 and 16 times below the threshold in CRT and grinding areas respectively. The non-CR medians were 2 and 3 times below the threshold, although in the CRT area one exceptional value surpassed the threshold, suggesting that risk can exist for some workers in the facility., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Radon is a radioactive, carcinogenic gas formed by the radioactive decay of uranium and radium that occur naturally in small amounts in all rocks and soils. It is the largest single source of radiation exposure to the UK population, contributing to more than 1 100 lung cancer deaths each year according to an analysis conducted in 2005. Regulations exist to protect employees (and other persons) where radon concentrations exceed the reference level of 300 Bq m -3 . Once the reference level is exceeded, annual doses of more than the public dose limit of 1 mSv a -1 are considered to be excessive. A radon measurement campaign for schools, which started in 2009, generated a large dataset, including those with high numbers of simultaneous radon measurements. Radon data between buildings (e.g. homes) have been shown to correspond broadly to the lognormal distribution, after the additive contribution of outside air has been removed. However, there are fewer studies of the distribution of radon levels within a single, large property. Radon data collected from 533 UK schools with at least 20 valid, simultaneous results were analysed against several statistical models. In approximately 50% of schools the radon levels could be represented by the lognormal distribution and in 60% by the loglogistic lognormal distribution, the latter being a better fit probably owing to its lower sensitivity to the tails of the distribution. Qualitatively, the lognormal and the loglogistic probability plots appeared to be indistinguishable. These findings indicate that the lognormal and loglogistic might be appropriate models to characterise the distribution of radon in most large workplaces. For each statistical model, the two distribution parameters can be used to provide a better estimate of the average dose to the occupants. However, caution is required when assessing doses, since the average estimator of the radon concentration does not predict the highest value and may significantly underestimate or overestimate the dose in specific areas., (Creative Commons Attribution license.)

Objective: To assess the diagnostic utility of lncRNA 51 A in detecting cognitive decline among aluminum-exposed workers occupationally., Methods: 921 male workers from an aluminum manufacturing facility underwent cognitive assessments, measurement of plasma aluminum levels and quantification of lncRNA 51 A levels. Receiver Operating Characteristic (ROC) curves were constructed to assess the diagnostic potential of lncRNA 51 A. Bayesian network model was utilized to predict the likelihood of cognitive decline among the study population., Results: Significant differences in lncRNA 51 A levels, plasma aluminum concentration and MMSE scores were observed between cognitive normal and decline groups. The lncRNA 51 A expression was negatively correlated with MMSE scores. The area under the curve (AUC) was 0.894, with 89.3 % sensitivity and 73.9 % specificity. The Bayesian network model indicated varying probabilities of cognitive decline based on lncRNA 51 A expression levels., Conclusion: Plasma lncRNA 51 A shows potential as an excellent biomarker for cognitive decline diagnosis in aluminum-exposed workers., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Occupational exposure to particulate matter (PM) can result in multiple adverse health effects and should be minimized to protect workers' health. PM exposure at the workplace can be complex with many potential sources and fluctuations over time, making it difficult to control. Dynamic maps that visualize how PM is distributed throughout a workplace over time can help in gaining better insights into when and where exposure occurs. This study explored the use of spatiotemporal modeling followed by kriging for the development of dynamic PM concentration maps in an experimental setting and a workplace setting. Data was collected using personal low-cost PM sensors and an indoor location tracking system, mounted on a moving robot or worker. Maps were generated for an experimental study with one simulated robot worker and a workplace study with four workers. Cross-validation was performed to evaluate the performance and robustness of three types of spatiotemporal models (metric, separable, and summetric) and, as an additional external validation, model estimates were compared with measurements from sensors that were placed stationary in the laboratory or workplace. Spatiotemporal models and maps were generated for both the experimental and workplace studies, with average root mean squared error (RMSE) from 10-fold cross-validation ranging from 7-12 and 73-127 µg/m 3 , respectively. Workplace models were relatively more robust compared to the experimental study (relative SD ranging from 8-14% of the average RMSE vs. 27-56%, respectively), presumably due to the larger number of parallel measurements. Model estimates showed low to moderate fits compared to stationary sensor measurements (R 2 ranging from 0.1-0.5), indicating maps should be interpreted with caution and only used indicatively. Together, these findings show the feasibility of using spatiotemporal modeling for generating dynamic concentration maps based on personal data. The described method could be applied for exposure characterization within comparable study designs or can be expanded further, for example by developing real-time, location-based worker feedback systems, as efficient tools to visualize and communicate exposure risks.

Recycling electronic waste (e-waste) poses risks of metal exposure, potentially leading to health impairments. However, no previous study has focused on this issue in Hong Kong. Therefore, from June 2021 to September 2022, this study collected urine samples from 101 e-waste workers and 100 office workers in Hong Kong to compare their urinary levels of metals using ICP-MS. Among the 15 included metals (with detection rates above the 70 % threshold), eight showed significantly higher urinary concentrations (unit: μg/g creatinine) in e-waste workers compared to office workers: Li (25.09 vs. 33.36), Mn (1.78 vs. 4.15), Ni (2.10 vs. 2.77), Cu (5.81 vs. 9.23), Zn (404.35 vs. 431.52), Sr (151.33 vs. 186.26), Tl (0.35 vs. 0.43), and Pb (0.69 vs. 1.16). E-waste workers in Hong Kong generally exhibited lower metal levels than those in developing regions but higher than their counterparts in developed areas. The urine level of 8-hydroxy-2-deoxyguanosine (8-OHdG) was determined by HPLC-MS/MS, and no significant difference was found between the two groups. Multiple linear regression models revealed no significant association between individual metal and urinary 8-OHdG concentrations. However, the metal mixture was identified to marginally elevate the 8-OHdG concentrations (1.12, 95 %CI: 0.04, 2.19) by quantile g‑computation models, with Mn and Cd playing significant roles in such effect. In conclusion, while the metal levels among Hong Kong e-waste workers compared favorably with their counterparts in other regions, their levels were higher than those of local office workers. This underscores the need for policymakers to prioritize attention to this unique industry., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The maturation of robotic and remote systems presents opportunities to expand the use of technologies that have typically been restricted to high-dose/high-risk nuclear work for moderate- or low-risk work to further reduce radiation exposure to workers. This study quantifies the potential dose savings achieved through the use of robotic techniques for characterizing transuranic-contaminated waste items and compares dose estimates from a simplistic, user-friendly deterministic radiation transport code and a more robust, complex Monte Carlo code. Three scenarios of transuranic-contaminated waste items described in published reports are modeled using representative source geometries in MicroShield and MCNP radiation transport codes. Estimated dose rates are determined at points ranging from 30 cm to 300 cm from the face of the waste item to represent the increase in distance allowed by robotic or remote system implementation for characterization activities. The dose rate savings are then converted to detriment cost savings using a dollar-per-person-dose conversion factor to provide a financial context. The radiation transport simulations show no consistent bias in estimated dose rate by varying simulation methodology or using geometrical simplifications-in some cases, MicroShield produces higher dose rate estimates while MCNP estimates are higher in other cases. In the MCNP simulations, the volume source geometry consistently produces a higher dose rate than the slab source geometry, but the MicroShield dose rate estimates do not display the same trend. Dose savings range from 1.60 × 10-5 μSv h-1 to 1.75 × 101 μSv h-1 with associated detriment cost savings from < 0.010 USD/person-h to 14 USD/person-h., (Copyright © 2024 Health Physics Society.)

This research focused on the determination of scatter radiation levels in x-ray rooms during chest radiography. 108 patients were examined. Four x-ray machines (A, B, C, and D) were used during the research from three centers. Three positions were considered in this study; position Q just beside the (Bucky stand), position R, which is 150 cm from the left of the Bucky stand towards the door and position T, 200 cm from the Bucky stand to the radiographer's protective screen respectively. Two machines (A and B) from center 1 and one machine from center 2 (C) and one machine from center 3 (D). The body mass index (BMI) of the participants ranged from 20 to 25 kgm -2 with mean value of 23.97 kgm -2 . The background radiation level was read using Radalert 100 m before any exposure, and the mean background level was 0.298 mR/h. The mean of the scatter radiation doses obtained from positions Q with respect to the four machines A, B, C, and D, were 0.109, 0.201, 0.204, 0.200 mR/h (9.166, 16.903, 17.156, 16.819 mSv/yr) and their standard deviations were ±0.052, ±0.053, ±0.064, and ±0.081 respectively. The results were comparable with previous studies. The study recommends staff education and training in determination of radiation levels for enhanced work safety., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The goal of this study is to measure the uranium concentration levels in the blood of Iraqi workers employed in certain government companies. Assessing the initial level of uranium toxicity in their blood and the possibility of health problems occurring. 184 blood samples from Iraqi government companies and the control group were collected in this study. A solid-state nuclear track detector (CR-39) was used to measure the amount of uranium present. Two drops of blood (100 μl) were placed on CR-39. The CR-39 was irradiated with a thermal neutron using the fission-track technique ( 241 Am- 9 Be) to determine the uranium concentration in blood samples. The statistical analysis is carried out using the Origin Lab 2024 version. The results show the average of uranium concentration at all locations has a higher level compared to the control group. The blood samples from workers at the phosphate company had the highest amount (1.021 ± 0.050 μg/l), compared to samples from other factories. This result confirms that there is a connection between the concentration of uranium and phosphate substances. The results suggest that there is a slight increase in uranium levels that is related to both age and years of employment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Polycyclic aromatic compounds (PAHs) are formed during incomplete combustion and firefighters are inadvertently at risk of being exposed to these and other hazardous compounds. Exposure to PAHs is often estimated by measuring their hydroxylated metabolites (OH-PAH) in urine. Here, an online-SPE LC-MS-MS method was set up for eight OH-PAHs thus increasing sample throughput and minimizing manual handling. The method was validated over a 5-month period and showed good reproducibility with intra- and inter-day variation of 2.4-8.1 % and 1.6-6.5 %, respectively, of low-level samples and accuracy (91.6-104.8 %) for a standard reference material. The method was applied to urine samples from conscripts training to become firefighters to determine the optimal sampling time for this training activity before a large intervention study. In total, six conscripts sampled urine 6-8 times over a 40-hr period during a 3-day training course. All eight metabolites were detected in ≥ 97 % of the samples and showed peak excretion 4-6 hrs after the training corresponding to 8-10 hrs after first exposure. Samples taken the morning after the exercise contained low levels of most metabolites. Consequently, 4-6 hrs post exposure is recommended as the optimal sampling time for quantification of PAH exposure and monitoring of potential differences in exposure., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Introduction: Exposure of healthcare workers to hazardous drugs can lead to adverse health effects supporting the importance of a continuous monitoring program, for example, by taking surface wipe samples. The objective was to describe the results of repeated monitoring of contamination with hazardous drugs on multiple surfaces in a hospital pharmacy and at two wards using standardized preparation techniques and cleaning procedures., Methods: Twelve surfaces in the hospital pharmacy and at two wards were sampled and analyzed for contamination with the hazardous drugs cyclophosphamide, doxorubicin, 5-fluorouracil, gemcitabine, methotrexate, and paclitaxel. The drugs were prepared with a closed-system drug transfer device (CSTD). Sampling of the drugs was performed in four trials during eight months. Liquid chromatography tandem mass spectrometry was used for the analysis of the drugs., Results: During the four trials, contamination with five of the six hazardous drugs was found on half of the surfaces in the pharmacy and in a ward. Seventeen out of 288 possible outcomes were positive (6%), with the biological safety cabinet grate ( n  = 6) and scanner ( n  = 5) most frequently contaminated. The highest level of contamination was observed on the pass-thru window (cyclophosphamide: 2.90 ng/cm 2 ) and the touch screen of the Diana device (5-fluorouracil: 2.38 ng/cm 2 ). Both levels were below the action level of 10 ng/cm 2 ., Conclusions: The long-term use of a CSTD in combination with appropriate cleaning has proven effective in achieving low levels of surface contamination with hazardous drugs., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: Meat processing is among the most extensive industries globally. However, data on the effects of occupational exposure on the pulmonary health of slaughterhouse workers is limited. Ascertaining the impact of the slaughterhouse atmosphere on the breathing habits of laborers exposed to it and the inflammatory markers associated with it was the aim of the current investigation., Methods: A cross-sectional study was performed on 82 non-smoker subjects of 41 male workers working in one of the major slaughterhouses in Cairo, Egypt, matched to 41 controls of administrative personnel. An elaborate questionnaire encompassing medical and occupational history was administered to each participant in the research. General and local systemic examinations and ventilatory function tests were carried out, and serum levels of interleukin 6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) were measured., Results: Respiratory symptoms were more prevalent with a statistically significant decline in ventilatory function parameters (FVC%, FEV1%, FEV1/FVC, FEF 25%, FEF 50%, FEF 75%, and PEF%) among the exposed group compared to those of control. In addition, there was a significantly higher serum level of inflammatory markers (IL-6 and hsCRP) among the exposed group compared to the control group, with a negative correlation with ventilatory functions. Moreover, there was a positive association between levels of serum IL-6 and hsCRP and the age and duration of employment of workers., Conclusion: There was a notable increase in the prevalence of respiratory disorders and inflammatory markers among slaughterhouse workers. Additionally, there was a substantial decrease in ventilatory function parameters, which could be attributed to the bioaerosols they encountered in the workplace., (© 2024. The Author(s).)

Benzene is associated with diverse occupational and public health hazards. It exhibits an ability to rapidly permeate the skin and contaminate water and food sources, leading to dermal and ingestion exposures. Despite numerous studies examining the associations between benzene and various indicators of harm, the findings have yielded inconsistent results. Furthermore, relying solely on air concentration as a measure of benzene exposure is limited, as it fails to account for internal exposure dose and individual susceptibility. This study aimed to conduct a comprehensive review in order to present current knowledge on benzene biomarkers and their significance in evaluating exposure levels and associated health hazards. The search methodology adhered to the PRISMA guidelines and involved the application of specific inclusion and exclusion criteria across multiple databases including PubMed, Embase, and Web of Science. Two researchers independently extracted and evaluated the relevant data based on predetermined criteria. Following the screening process, a total of 80 articles were considered eligible out of the initially retrieved 1053 articles after undergoing screening and assessment for inclusion. As the level of exposure decreased, specific biomarkers demonstrated a gradual increase in limitations, including heightened background concentrations and vulnerability to confounding factors. The advancement of sampling and analysis techniques will yield new biomarkers. Additionally, when conducting practical work, it is crucial to employ a comprehensive utilization of diverse biomarkers while excluding individual metabolic variations and combined exposure factors., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Abstract: Nuclear industry workers exposed to uranium aerosols may risk kidney damage and radiation-induced cancer. This warrants the need for well-established dose and risk assessments, which can be greatly improved by using material-specific absorption parameters in the ICRP Human Respiratory Tract Model. The present study focuses on the evaluation of the slow dissolution rate ( s s , d -1 ), a parameter that is difficult to quantify with in vitro dissolution studies, especially for more insoluble uranium compounds. A long-term follow-up of urinary excretion after the cessation of chronic inhalation exposure can provide a better estimate of the slow-rate dissolution. In this study, two workers, previously working for >20 y at a nuclear fuel fabrication plant, provided urine samples regularly for up to 6 y. One individual had worked at the pelletizing workshop with the known presence of uranium dioxide (UO 2 ) and triuranium octoxide (U 3 O 8 ). The second individual worked at the conversion workshop where multiple compounds, including uranium hexafluoride (UF 6 ), uranium dioxide (UO 2 ), ammonium uranyl carbonate, and AUC [UO 2 CO 3 ·2(NH 4 ) 2 CO 3 ], are present. Data on uranium concentration in urine during working years were also available for both workers. The daily excretion of uranium by urine was characterized by applying non-linear least square regression fitting to the urinary data. Material-specific parameters, such as the activity median aerodynamic diameter (AMAD), the respiratory tract absorption parameters, rapid fraction ( f r ,), rapid dissolution rate ( s r , d -1 ), and slow dissolution rate ( s s , d -1 ) and alimentary tract transfer factor ( f A ) acquired from previous work along with default absorption types, were applied to urine data, and the goodness of fit was evaluated. Thereafter intake estimates and dose calculations were performed. For the ex-pelletizing worker, a one-compartment model with a clearance half-time of 662 ± 100 d ( s s = 0.0010 d -1 ) best represented the urinary data. For the ex-conversion worker, a two-compartment model with a major [93% of the initial urinary excretion (A 0 )] fast compartment with a clearance half-time of 1.3 ± 0.4 d ( s r = 0.5 d -1 ) and a minor (7% of A 0 ) slow compartment with a half-time of 394 ± 241 d ( s s = 0.002 d -1 ) provided the best fit. The results from the data-fitting of urinary data to biokinetic models for the ex-conversion worker demonstrated that in vitro derived experimental parameters (AMAD = 20 μm, f r = 0.32, s r = 27 d -1 , s s = 0.0008 d -1 , f A = 0.005) from our previous work best represented the urinary data. This resulted in an estimated intake rate of 0.66 Bq d -1 . The results from the data-fitting of urinary data to biokinetic models for the ex-pelletizing worker indicated that the experimental parameters (AMAD = 10 μm and 20 μm, f r = 0.008, s r = 12 d -1 , f A = 0.00019) from our previous dissolution studies with the slow rate parameter step-wise optimized to urine-data ( s s = 0.0008 d -1 ) gave the best fit. This resulted in an estimated intake rate of 5 Bq d -1 . Experimental parameters derived from in vitro dissolution studies provided the best fit for the subject retired from work at the conversion workshop, where inhalation exposure to a mix of soluble (e.g., AUC, UF 6 ) and relatively insoluble aerosol (e.g., UO 2 ) can be assumed. For the subject retired from work at the pelletizing workshop, which involved exposure to relatively insoluble aerosols (UO 2 and U 3 O 8 ), a considerably higher s s than obtained in dissolution studies provided a better representation of the urinary data and was comparable to reported s s values for UO 2 and U 3 O 8 in other studies. This implies that in vitro dissolution studies of insoluble material can be uncertain. When evaluating the results from the retrospective fitting of urine data, it is evident that the urine samples acquired after cessation of exposure provide less fluctuation. Long-term follow-up of uranium excretion after cessation of exposure is a good alternative for determining absorption parameters and can be considered the most viable way for determining the slow rate for more insoluble material., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Health Physics Society.)

High concentrations of PM 2.5 with enriched levels of metallic constituents could significantly affect the health and comfort of metro employees. To avoid overestimating the exposure risks, we investigated the bioaccessibility of toxic metals (TMs) bound in PM 2.5 from the Nanchang metro using Gamble's solution method, and qualitatively analyzed the impact of valence state and various sources on the bioaccessibility of TMs bound to PM 2.5 . The results showed that the bioaccessibility of the studied TMs ranged from 2.1% to 88.1%, with As, Ba, Co and Pb being the most bioaccessible and V, Fe and Cr being the less bioaccessible. The bioaccessibility of TMs in our subway PM 2.5 samples varied based on their valence and species, showing higher valence states associated with increased bioaccessibility. Vehicle traffic, secondary aerosols and wheel/rail sources were found to be significantly and positively associated with the bioaccessibility of several TMs, implying a severe potential risk from these three sources. Although both non-carcinogenic and carcinogenic risks associated with total TMs were found to be high, only As and Cr(VI) posed a considerable carcinogenic risk to metro workers based on the bioaccessible fractions and were therefore priority pollutants. In addition, potential carcinogenic risk was found to be more severe in platform than that in ticket counter. The results indicate that considerable efforts are required to control and manage PM 2.5 and the associated TMs in the Nanchang subway, particularly from traffic, wheel/rail and secondary sources, to protect the health of metro staff and the public., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)