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The monthly and spatial variations of atmospheric dustfall (DF) and their elemental components were determined. The DF sampling was performed using the ASTM method D-1739 from April 2017 to March 2018 in four urban and suburb sampling sites around Tabriz, Iran. The ICP-OES was utilized for the determination of the elemental components of DF. The results showed that the level of DF varied from 1.3 to 27.6 (8.0 ± 3.4) g/m2.month during the sampling period, and the level of DF was higher in warm seasons than cold seasons. Also, it was revealed that the mean DF has a direct and significant relationship with temperature, wind speed, and relative humidity. The elements of Fe (11,997–17,093 mg/Kg and 71–81%) and Al (2903–6852 mg/Kg and 14–25%), which are the main elements of the Earth crust, were the dominant metals of DF among the analyzed elements. The lowest average value of the enrichment factor (EF) was for Al and was 10 in all the sites, indicating that anthropogenic emission sources spread a considerable amount of trace elements in DF compared to the Lake Urmia bed or soil. The EF values for various elements (except than Cu and Hg) in cold seasons considerably increased compared to warm seasons. In all the study sites, Fe (540–1307 mg/m2.yr) had the highest deposition rates among the metals. This study revealed that the Earth crust is the main source of DF in the region.

PURPOSE: We aimed to investigate the spatial O(3) indices (SOMO35: annual sum of maximum daily 8-h ozone means over 35 ppb, AOT40: the accumulated exposure over an hourly threshold of 40 ppb during daylight hours between 8:00 and 20:00 in the growing seasons of plants) in Tehran (2019–2020). METHODS: The data of ambient O(3) concentrations, measured at twenty-three regulatory ambient air quality monitoring stations (AQMSs) in Tehran, were obtained. RESULTS: The annual mean O(3) concentrations were found to be 15.8–25.7 ppb; the highest and lowest annual mean concentration of ambient O(3) were observed in Shahrdari 22 and Shahr-e-Rey stations, respectively. Spatial distribution of exposure to O(3) across Tehran was in the range of 1.36–1.64; the highest O(3) concentrations were observed in the northern, west and south-western parts of Tehran, while the central and south areas of Tehran city experienced low to moderate concentrations. The indices of SOMO35, AOT40f and AOT40v across AQMSs in Tehran was in the range of 1830–6437 ppb. Days, 10,613–39,505 ppb.h and 4979–16,804 ppb.h, respectively. For Tehran city, the indices of SOMO35 and AOT40f were 4138 ppb. days and 27,556 ppb.h respectively. Our results revealed that the value of SOMO35 across AQMSs of Tehran was higher than the recommended target value of 3000 ppb. days. CONCLUSIONS: To reduce O(3) pollution and its effects on both human and plants health, the governmental organizations should take appropriate sustainable control policies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40201-020-00552-2) contains supplementary material, which is available to authorized users.

Respirator face masks (RFMs) as a personal-level intervention is increasingly being utilized to reduce ambient particulate matter (PM) exposure, globally. We tested the effectiveness of 50 commercially available ones in reducing the exposure of ambient particle number concentrations (PNC), PM10, PM2.5, and PM1 (PM ≤ 10, 2.5, and 1 μm in diameter, respectively) in a traffic-affected urban site in Tehran. To examine the efficiency of RFMs, we applied a specific experimental setup including vacuum pumps, dummy heads, connecting tubes, glass chambers, and GRIMM Aerosol Spectrometer to measure all metrics after dummy heads. The average effectiveness of RFMs was in the range of 0.7-83.5%, 3.5-68.1%, 0.8-46.1%, and 0.4-32.2% in reducing ambient PNC, PM10, PM2.5, and PM1, respectively. Considering all metrics, the highest effectiveness was observed always for Biomask, followed by 3 M 9332, due to their well-designed physical characteristics (e.g., adjustable nose clip for any face/nose shape, and size, soft inner material in the nose panel to provide a secure seal against leakage, adjustable or elasticated straps/ear loops to better adjust on any face). Biomask reduced ambient PM10 with a mean value of 94.6 μg m-3 (minimum-maximum: 51.7-100.3 μg m-3), whereas it filtered on average just 29.0 μg m-3 (25.7-43.5 μg m-3) of ambient PM2.5 and 18.2 μg m-3 (14.7-21.8 μg m-3) of PM1. A fuzzy analytical hierarchy process to find the most important design-related factors of RFMs affecting their effectiveness, which showed the exhalation valve and its diaphragm (20.4%), nose clip (19.7%), and cheek flaps (18.6%) are ranked as the main design-related variables. The fuzzy technique for order preference by similarity to ideal solution indicated that Biomask and 3M 9332 had scores of 1 and 0.97, the highest scores compared with other RFMs. This study provides crucial evidence-based results to elucidate the effectiveness and design-related factors of RFMs in real-environmental circumstances.

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has indirectly produced both positive and negative effects on the environment, particularly in terms of air quality. Our study aimed to determine these effects in the city of Tehran by comparing the ambient PM2.5 and PM10 levels recorded at 22 air quality monitoring stations during the outbreak (20 February–2 April 2020) with those from the corresponding period last year (20 February–3 April 2019). Contrary to expectation, the average concentrations of both the PM2.5 and the PM10 were markedly higher during the former, increasing by 20.5% and 15.7%, respectively, for the first month of the outbreak (20 February–19 March 2020) and by 23.5% and 20.0% for the subsequent Nowruz New Year holidays (from late March till early April), which resulted in overall increases of 20.5% and 16.5% for the entire period. The non-integrated responses to the pandemic, including the failure to close administrative centers and, in particular, the recommendation to maintain social distancing by reducing public transportation use (prompting citizens to travel by private vehicle), have worsened the ambient air quality in Tehran, providing an exceptional opportunity to evaluate the direct/indirect influence of air quality policies and emission control measures on PM2.5 and PM10. Because of the significant association between the lethality of coronavirus disease 2019 (COVID-19) and exposure to ambient air pollution, the rise in airborne PM2.5 during this outbreak may increase the mortality rate of SARS-CoV-2.

We conducted this systematic review to identify and appraise studies investigating the coronavirus disease 2019 (COVID-19) effect on ambient air pollution status worldwide. The review of studies was conducted using determined search terms via three major electronic databases (PubMed, Web of Science, and Scopus) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. A total of 26 full-text studies were included in our analysis. The lockdown measures related to COVID-19 pandemic caused significant decreases in the concentrations of PM2.5, NO2, PM10, SO2 and CO globally in the range of 2.9%–76.5%, 18.0%–96.0%, 6.0%–75.0%, 6.8%–49.0% and 6.2%–64.8%, respectively. However, O3 concentration increased in the range of 2.4%–252.3%. The highest decrease of PM2.5 was found in 16 states of Malaysia (76.5%), followed by Zaragoza (Spain) with 58.0% and Delhi (India) with 53.1%. The highest reduction of NO2 was found in Sale city (Morocco) with 96.0%, followed by Mumbai (India) with 75.0%, India with 70.0%, Valencia (Spain) with 69.0%, and Sao Paulo (Brazil) with 68.0%, respectively. The highest increase of O3 was recorded for Milan (Italy) with 252.3% and 169.9% during the first and third phases of lockdown measures, and for Kolkata (India) with 87% at the second phase of lockdown measures. Owing to the lockdown restrictions in the studied countries and cities, driving and public transit as a proxy of human mobilities and the factors affecting emission sources of ambient air pollution decreased in the ranges of 30–88% and 45–94%, respectively. There was a considerable variation in the reduction of ambient air pollutants in the countries and cities as the degree of lockdown measures had varied there. Our results illustrated that the COVID-19 pandemic had provided lessons and extra motivations for comprehensive implementing policies to reduce air pollution and its health effects in the future.

Particulate-filtering respirators (PFRs) have been recommended as a practical personal-level intervention to protect individuals from the health effects of particulate matter exposure. However, the cardiovascular benefits of PFRs including improvements in key surrogate endpoints remain unclear. We performed a systematic review and meta-analysis of randomized studies (wearing versus not wearing PFRs) reporting the effects on blood pressure (BP) and heart rate variability (HRV). The search was performed on January 3, 2022 to identify published papers until this date. We queried three English databases, including PubMed, Web of Science Core Collection and Scopus. Of 527 articles identified, eight trials enrolling 312 participants (mean age ± standard deviation: 36 ± 19.8; 132 female) met our inclusion criteria for analyses. Study participants wore PFRs from 2 to 48 h during intervention periods. Wearing PFRs was associated with a non-significant pooled mean difference of -0.78 mmHg (95% confidence interval [CI]: -2.06, 0.50) and -0.49 mmHg (95%CI: -1.37, 0.38) in systolic and diastolic BP (SBP and DBP). There was a marginally significant reduction of mean arterial pressure (MAP) by nearly 1.1 mmHg (95%CI: -2.13, 0.01). The use of PFRs was associated with a significant increase of 38.92 ms

This randomized crossover trial sought to determine whether wearing a high-efficiency particulate-filtering respirator (PFR) improves cardiovascular function over 48 h among healthy college students in Tehran. This trial was conducted from February 14th to 23rd, 2019 and twenty-six participants completed two 48-h intervention periods. Brachial blood pressure (BP) measured by 24-h ambulatory monitoring was the primary health outcome. Secondary outcomes included 48-h heart rate variability (HRV) indices, high-sensitive cardiac troponin (hs-TnT) and other biomarkers. The participants wore the PFR between 10.2 and 11.1 h while awake during the interventions. More than 80% of participants reported increased respiratory resistance while wearing the PFR due to a lack of an exhalation valve. There were no significant differences in brachial BP levels between subjects who wore PFR respirator and those did not. Except for high frequency (HF) power and heart rate (HR), no significant differences between interventions were observed for other HRV metrics. Wearing the PFR led to an increase of 66.0 ms2 (95% confidence interval [CI], 9.6-110.5) and 79.6 ms2 (95% CI, 19.0-140.1) in HF power during the first day when the two groups of participants wore the PFR. Night-time HR was significantly increased during the PFR intervention period. Other secondary outcomes were not significantly different between interventions. It is plausible that incomplete exposure reduction due to wearing the PFR less than half of the time or increased respiratory resistance mitigated potential health benefits. Additional trials are warranted to validate the CV protection of wearing PFRs in heavily-polluted cities.

In this study, we investigated the association between short-term exposure to different sources of fine particulate matter (PM

The coronavirus disease 2019 (COVID-19) emerged in Wuhan city, China, in late 2019 and has rapidly spread throughout the world. The major route of transmission of SARS-CoV-2 is in contention, with the airborne route a likely transmission pathway for carrying the virus within indoor environments. Until now, there has been no evidence for detection of airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and this may have implication for the potential spread of the COVID-19. We investigated the air of patient rooms with confirmed COVID-19 in the largest hospital in Iran, on March 17, 2020. To collect the SARS-CoV-2 particles, ten air samples were collected into the sterile standard midget impingers containing 20 mL DMEM with 100 μg/mL streptomycin, 100 U/mL penicillin and 1% antifoam reagent for 1 h. Besides, indoor particle number concentrations, CO2, relative humidity and temperature were recorded throughout the sampling duration. Viral RNA was extracted from samples taken from the impingers and Reverse-Transcription PCR (RT-PCR) was applied to confirm the positivity of collected samples based on the virus genome sequence. Fortunately, in this study all air samples which were collected 2 to 5 m from the patients' beds with confirmed COVID-19 were negative. Despite we indicated that all air samples were negative, however, we suggest further in vivo experiments should be conducted using actual patient cough, sneeze and breath aerosols in order to show the possibility of generation of the airborne size carrier aerosols and the viability fraction of the embedded virus in those carrier aerosols., Graphical abstract Unlabelled Image, Highlights • To address the airborne transmission mode of SARS-CoV-2 air samples were collected in the largest hospital in Iran. • Our results indicated that all collected samples were negative in terms of the viral RNA. • We did not detect any positive readings 2 m from the patients' beds.

The main objectives of this study were (1) investigation of the temporal variations of ambient fine particulate matter (PM; 2.5; ) and ground level ozone (O; 3; ) concentrations in Tehran megacity, the capital and most populous city in Iran, over a 10-year period from 2006 to 2015, and (2) estimation of their long-term health effects including all-cause and cause-specific mortality. For the first goal, the data of PM; 2.5; and O; 3; concentrations, measured at 21 regulatory monitoring network stations in Tehran, were obtained and the temporal trends were investigated. The health impact assessment of PM; 2.5; and O; 3; was performed using the World Health Organization (WHO) AirQ+ software updated in 2016 by WHO European Centre for Environment and Health. Local baseline incidences in Tehran level were used to better reveal the health effects associated with PM; 2.5; and O; 3; . Our study showed that over 2006-2015, annual mean concentrations of PM; 2.5; and O; 3; varied from 24.7 to 38.8 μg m; -3; and 35.4 to 76.0 μg m; -3; , respectively, and were significantly declining in the recent 6 years (2010-2015) for PM; 2.5; and 8 years (2008-2015) for O; 3; . However, Tehran citizens were exposed to concentrations of annual PM; 2.5; exceeding the WHO air quality guideline (WHO AQG) (10 μg m; -3; ), U.S. EPA and Iranian standard levels (12 μg m; -3; ) during entire study period. We estimated that long-term exposure to ambient PM; 2.5; contributed to between 24.5% and 36.2% of mortality from cerebrovascular disease (stroke), 19.8% and 24.1% from ischemic heart disease (IHD), 13.6% and 19.2% from lung cancer (LC), 10.7% and 15.3% from chronic obstructive pulmonary disease (COPD), 15.0% and 25.2% from acute lower respiratory infection (ALRI), and 7.6% and 11.3% from all-cause annual mortality in the time period. We further estimated that deaths from IHD accounted for most of mortality attributable to long-term exposure to PM; 2.5; . The years of life lost (YLL) attributable to PM; 2.5; was estimated to vary from 67,970 to 106,706 during the study period. In addition, long-term exposure to O; 3; was estimated to be responsible for 0.9% to 2.3% of mortality from respiratory diseases. Overall, long-term exposure to ambient PM; 2.5; and O; 3; contributed substantially to mortality in Tehran megacity. Air pollution is a modifiable risk factor. Appropriate sustainable control policies are recommended to protect public health.

The recently published article (https://doi.org/10.1016/j.envres.2018.11.046), authored by Mohsen Ansari and Mohammad Hassan Ehrampoush (2019), was read with keen interest and in detail. The article aimed to investigate the correlation between ambient fine particulate matter (PM2.5, particulate matter with aerodynamic diameter 2.5 μm and smaller) and meteorological parameters, such as temperature, humidity, precipitation and wind speed. Additionally, the World Health Organization AirQ + software, updated in 2016 by WHO European Centre for Environment and Health, was applied to estimate all-cause and also five specific causes of death (namely, ischemic heart disease (IHD), cerebrovascular disease (stroke), lung cancer (LC), chronic obstructive pulmonary disease (COPD) and acute lower respiratory infection (ALRI)) due to long-term exposure to PM2.5 in Tehran from for the year spanning March 2017 to March 2018. It was reported that the authors obtained hourly concentrations of ambient PM2.5 from Air Quality Monitoring Stations (AQMSs) operated by the Tehran Air Quality Control Company (TAQCC). Other required data also were gathered from governmental organizations, including the Statistical Centre of Iran (SCI), the Civil Registration Office of Tehran, and the Ministry of Health and Medical Education. We believe there are a number of controversial issues that should be brought to the attention of readers, especially within the materials and methods sections, including “Description of Study Area”, “Air Pollution Data Monitoring and Exposure Assessment” and “AirQ+ Software”; and in subsequent sections, we also highlight some issues impacting the interpretability of the article.

Numerous studies have found that risk of cardiovascular diseases is associated with increased blood levels of circulating markers of systemic inflammation. We investigated associations of acute exposure to bioaerosols (bacteria and fungi) with blood markers of inflammation and coagulation using panels of elderly subjects and healthy young adults. We conducted a panel study of 44 nonsmoker elderly subjects in a retirement communities and a panel study of 40 healthy young adults living in a school dormitory within Tehran city, Iran. Blood sample biomarkers were measured weekly over 6 weeks and including high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), von Willebrand factor (vWF), white blood cells (WBC) count and interleukin-6 (IL-6). We found significant positive associations for IL-6 and WBC with exposure to Aspergillus spp. (As), Cladosporium spp. (Cl), Penicillium spp. (Pe), total fungi (TF) and Micrococcus spp. (MI); vWF with Cl and MI; sTNF-RII with Staphylococcus spp. (ST) in healthy young adults from the current-day and multiday averages. For elderly subjects, we observed significant positive associations for hsCRP, sTNF-RII and WBC with exposure to MI, but not with ST and total bacteria (TB). Our results showed the strongest significant positive associations for IL-6 with MI, ST and TB in elderly people. In addition, IL-6 was also positively associated with As, Cl and Pe in elderly. Also, the results showed that increase of vWF was significantly associated with bacterial and fungal aerosols, except Bacillus spp. (BA) at some lags in elderly subjects. Pooled results support the pivotal role of bioaerosols in increasing the level of some of inflammatory biomarkers, especially IL-6 and WBC in healthy young adults but possibly also in elderly people.

Systemic inflammation biomarkers have been associated with risk of cardiovascular morbidity and mortality. We aimed to clarify associations of acute exposure to particulate matter (PM10 (PM

In this study, we investigated the association between short-term exposure to different sources of fine particulate matter (PM2.5) and biomarkers of coagulation and inflammation in two different panels of elderly and healthy young individuals in central Tehran. Five biomarkers, including white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF) were analyzed in the blood samples drawn every 8 weeks from the subjects between May 2012 and May 2013. The studied populations consisted of 44 elderly individuals at a retirement home as well as 40 young adults residing at a school dormitory. Positive Matrix Factorization (PMF)-resolved source-specific PM2.5 mass concentrations and biomarker levels were used as the input to the linear mixed-effects regression model to evaluate the impact of exposure to previously identified PM sources at retirement home and school dormitory in two time lag configurations: lag 1–3 (1–3 days before the blood sampling), and lag 4–6 (4–6 days before the blood sampling). Our analysis of the elderly revealed positive associations of all biomarkers (except hsCRP) with particles of secondary origin in both time lags, further corroborating the toxicity of secondary aerosols formed by photochemical processing in central Tehran. Moreover, industrial emissions, and road dust particles were positively associated with WBC, sTNF-RII, and IL-6 among seniors, while vehicular emissions exhibited positive associations with all biomarkers in either first- or second-time lag. In contrast, most of the PM2.5 sources showed insignificant associations with biomarkers of inflammation in the panel of healthy young subjects. Therefore, findings from this study indicated that various PM2.5 sources increase the levels of inflammation and coagulation biomarkers, although the strength and significance of these associations vary depending on the type of PM sources, demographic characteristics, and differ across the different time lags. Implications: Tehran, the capital of Iran with a population of more than 9 million people, has been facing serious air pollution challenges as a result of extensive vehicular, and industrial activities in the previous years. Among various air pollutants in Tehran, fine particulate matters (PM2.5, particles with aerodynamic diameters < 2.5 µm) are known as one of the most important critical pollutants, causing several adverse health impacts including lung cancer, respiratory, cardiovascular, and cardiopulmonary diseases. Therefore, a number of studies in the area have tried to investigate the adverse health impacts of exposure to PM2.5. However, no studies have ever been conducted in Tehran to examine the association between specific PM2.5 sources and biomarkers of coagulation and systemic inflammation as indicators of cardiovascular disorders. Indeed, this is the first study in the area investigating the association of source-specific PM2.5 with biomarkers of inflammation including white blood cells (WBC), high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), interleukin-6 (IL-6), and von Willebrand factor (vWF). Our results have important implications for policy makers in identifying the most toxic sources of PM2.5, and in turn designing schemes for mitigating adverse health impacts of air pollution in Tehran.

We investigated temporal variations of ambient air pollutants and the influences of meteorological parameters on their concentrations using a robust method; convergent cross mapping; in Tehran (2012–2017). Tehran citizens were consistently exposed to annual PM2.5, PM10 and NO2 approximately 3.0–4.5, 3.5–4.5 and 1.5–2.5 times higher than the World Health Organization air quality guideline levels during the period. Except for O3, all air pollutants demonstrated the lowest and highest concentrations in summertime and wintertime, respectively. The highest O3 concentrations were found on weekend (weekend effect), whereas other ambient air pollutants had statistically significant (P 3 concentration reached its peak at 3.00 p.m., though other air pollutants displayed two peaks; morning and late night. Approximately 45% to 65% of AQI values were in the subcategory of unhealthy for sensitive groups and PM2.5 was the responsible air pollutant in Tehran. Amongst meteorological factors, temperature was the key influencing factor for PM2.5 and PM10 concentrations, while nebulosity and solar radiation exerted major influences on ambient SO2 and O3 concentrations. Additionally, there is a moderate coupling between wind speed and NO2 and CO concentrations.

The present study aimed to find a correlation between the self-reported smoking status of the residents of Tehran, Iran, and the urine cotinine as a biomarker of exposure to tobacco smoke. The self-reported data was collected from 222 participants who were living in the urban area of Tehran. The urine samples of participants were collected for cotinine analysis. Urine cotinine was measured by an enzymatic immunoassay technique. Tobacco smoking was reported by 76 (34.23 %) participants as the self-reported data, and the number of males in this report was higher than of females (p 0.001). By adding the number of the self-reported non-smokers with cotinine levels above the cutoff value of100 ng/ml to self-reported smokers, the smoking prevalence increased from 34.23 % (95 % CI 28.01-40.88 %) to 36.48 % (95 % CI 30.14-43.19 %). Using the cutoff value, sensitivity and specificity of the self-reported smoking status were respectively 90.12 % (95 % CI 81.46-95.64 %) and 98 % (95 % CI 93.91-99.55 %). The levels of agreement between self-reported tobacco smoking and urinary cotinine concentrations was 95.1 % (k = 0.89, p 0.001, 95 % CI = 0.81-0.95). Based on the results, self-reported smoking can be a valid marker for assessing the tobacco exposure, and it can be of use in large epidemiological studies.

Ambient particulate matter is a public health concern. We aimed (1) to estimate national and provincial long-term exposure of Iranians to ambient particulate matter (PM) 2.5 μm (PM

This study was conducted to investigate the long-term temporal trends and spatial variations of ambient PM10, PM2.5 and O3 concentrations using the Moran’s I index and Mann-Kendall's test and also to evaluate their health effects in Tabriz city, between 2006 and 2017. The health impacts of air pollutants were estimated using the World Health Organization (WHO) AirQ + software updated in 2017. The results showed that the annual trend of PM concentrations was decreasing while O3 concentration was almost constant during the study period. The results indicated that in approximately 59 % and 4 % of the studied days for PM10, 48 % and 28 % for PM2.5, and 3 % and 0.3 % for O3, inhabitants of Tabriz city were exposed to the air pollutants in levels greater than the WHO AQG and National and U.S.EPA standard levels. Moreover, the highest monthly mean concentrations of PM10, PM2.5, and O3 were respectively observed in May (80.4 μg/m3), December (42.5 μg/m3), and June (78.4 μg/m3). It was estimated that attributable proportions due to long-term exposure to PM10 were between 7.9 % and 28.7 % for post neonatal infant mortality and between 20.7 % and 61.5 % for incidence of chronic bronchitis in adults. Long-term exposure to PM2.5 was attributed to about 11.8 % from all-cause, 34.6 % from ischemic heart disease, 26.7 % from stroke, 23.4 % from chronic obstructive pulmonary disease, 24.2 % from acute lower respiratory infection, and 16.5 % from lung cancer mortalities. Our study results showed that there were no effective policies and strategies to reduce Tabriz air pollution during the study period; and codification and implementation of effective control policies is necessary to improve ambient air quality of Tabriz.

The main aims of the present research were (1) investigation of the temporal trends of atmospheric benzene concentrations in Tehran city during the period 2010 to 2013 and (2) assessment of carcinogenic and non-carcinogenic health risks of inhalation exposure to benzene. For the first objective, the data of ambient air benzene concentrations were derived from 15 air quality monitoring stations (AQMSs) in Tehran during the years 2010 to 2013 and they were temporally investigated after data cleaning and missing data imputation. The excess lifetime cancer risk (ELCR) and hazard quotient (HQ) were estimated to reveal the carcinogenic and non-carcinogenic health effects of exposure to ambient benzene. Our findings indicated that over 2010-2013, annual mean concentrations of benzene were in the range of 1.84 to 2.57 μg m-3, and the highest annual mean concentration was observed in 2011 with a mean of 2.57 μg m-3. The four-year average concentration of benzene during the period from 2010 to 2013 was 2.14 μg m-3. Furthermore, the HQ for inhalation exposure to ambient benzene was lower than the acceptable risk level (HQ < 1) over the study time period which indicated that the non-carcinogenic effects are very unlikely to happen. In addition, health risk assessment for ELCR showed that the potential cancer risk for inhalation exposure to benzene was 1.67 × 10-5 over the study period, which is significantly higher than the limits recommended by the U.S. EPA (1 × 10-6). Our study clearly proves that the ambient benzene concentration in Tehran has substantially higher carcinogenic effects on the population. Appropriate sustainable control measures should be taken to reduce air benzene concentration and protect public health.

The aim of this study was to investigate environmental and lifestyle factors affecting exposure to PAHs in the general population in a large city of the Middle East (Tehran) by measuring urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and establishing relationships between PAHs exposure and related factors. Urine samples were collected from 222 randomly chosen subjects who were living in the urban area of Tehran, Iran. Subjects were required to complete a detailed questionnaire aimed to document their personal and sociodemographic information, activities, cooking-related appliances, smoking history/exposure, and consumed foodstuff. Identification and quantification of six OH-PAHs was carried out using a gas chromatography with mass spectrometry (GC-MS). The geometric means for 1-OHP, 1-NAP, 2-NAP, 2-FLU, 9-FLU, and 9-PHE for whole population study were 310, 1220, 3070, 530, 330, and 130 ng/g creatinine, respectively. The two naphthalene metabolites contributed on average 77% of the total concentration of six measured OH-PAHs, followed by the 2-FLU, 1-OHP, 9-FLU, and 9-PHE. The most important predictors of urinary PAHs were consumption of grilled/barbecued foods, smoking, and exposure to environmental tobacco smoking. Water pipe smoking was linked to urinary OH-PAH metabolite in a dose-response function. Residential traffic was also related with OH-PAH metabolite concentrations. Other factors including gender, age, exposure to common house insecticides, open burning, and candle burning were found to be statistically associated with the urinary levels of some OH-PAHs. High exposure to PAHs among general population in Middle Eastern large cities and its associated health implications calls for public health measures to reduce PAHs exposure.

The main objectives of this study were (1) investigation of the temporal variations of ambient fine particulate matter (PM

Background Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDFs) are highly toxic persistent organic pollutants (POPs), which can cause various health outcomes, such as cancer. As a part of the National and Sub-national Burden of Disease Study (NASBOD), we aimed to estimate dioxins and furans national emissions, identify their main sources, estimate daily intake doses, and assess their trend from 1990–2010 in Iran. Methods The Toolkit for Identification and Quantification of Releases of Dioxins, Furans and Other Unintentional POPs, which is developed by the United Nations Environment Programme (UNEP 2013), was used to estimate the emissions of PCDD/PCDFs from several sources into the air, water, land, residue, and other products. The daily intake doses were estimated using a linear regression of estimated emissions by UNEP Toolkit and average intake doses in other countries. Finally, the trend of PCDD/PCDFs emissions and daily intake doses were explored from 1990–2010. Results The total emissions were estimated as 960 g Toxic Equivalents (g TEQ) for 1990 and 1957 g TEQ for 2010 (18.2 and 26.8 g TEQ per million capita, respectively). The estimations suggest that albeit contribution of open burning to PCDD/PCDFs emissions has been declining from 1990 to 2010, it remained the major source of emissions in Iran contributing to about 45.8% out of total emissions in 1990 to 35.7% in 2010. We further found that PCDD/PCDFs are mostly emitted into the ambient air, followed by residue, land, products, and water. The daily intake doses were estimated to be 3.1 and 5.4 pg TEQ/kg bw/day for 1990 and 2010, respectively. We estimated an increasing trend for PCDD/PCDFs emissions and intake doses in Iran from 1990–2010. Conclusions The high levels of emissions, intake doses, and their increasing trend in Iran may pose a substantial health risk to the Iranian population. Further studies with more rigorous methods are recommended but this should not circumvent taking appropriate policy actions against these pollutants. Currently, Iran has no standard for dioxins and furans. Adaptation of the World Health Organization recommended guidelines might be an appropriate starting point to control dioxins and furans emissions.

The concentrations of bacterial and fungal bioaerosols were measured in a retirement home and a school dormitory from May 2012 to May 2013. In the present work, two active and passive methods were used for bioaerosol sampling. The results from the present work indicated that Bacillus spp., Micrococcus spp., and Staphylococcus spp. were the dominant bacterial genera, while the major fungal genera were Penicillium spp., Cladosporium spp., and Aspergillus spp. The results also indicated that the indoor-to-outdoor (I/O) ratios for total bacteria were 1.77 and 1.44 in the retirement home and the school dormitory, respectively; the corresponding values for total fungal spores were 1.23 and 1.08. The results suggested that in addition to outdoor sources, indoor sources also played a significant role in emitting bacterial and fungal bioaerosols in the retirement home and the school dormitory indoor.

Ambient particulate matter is a public health concern. We aimed (1) to estimate national and provincial long-term exposure of Iranians to ambient particulate matter (PM)

To investigate spatial inequality of ambient air pollutants and comparison of their heterogeneity and homogeneity across Tehran, the following quantitative indicators were utilized: coefficient of divergence (COD), the 90th percentile of the absolute differences between ambient air pollutant concentrations and coefficient of variation (CV). Real-time hourly concentrations of particulate matter (PM) and gaseous air pollutants (GAPs) of twenty-two air quality monitoring stations (AQMSs) were obtained from Tehran Air Quality Control Company (TAQCC) in 2017. Annual mean concentrations of PM2.5, PM10–2.5, and PM10 (PMX) ranged from 21.7 to 40.5, 37.3 to 75.0 and 58.0 to 110.4 μg m−3, respectively. Annual mean PM2.5 and PM10 concentrations were higher than the World Health Organization air quality guideline (WHO AQG) and national standard levels. NO2, O3, SO2 and CO annual mean concentrations ranged from 27.0 to 76.8, 15.5 to 25.1, 4.6 to 12.2 ppb, and 1.9 to 3.8 ppm over AQMSs, respectively. Our generated spatial maps exhibited that ambient PMX concentrations increased from the north into south and south-western areas as the hotspots of ambient PMX in Tehran. O3 hotspots were observed in the north and south-west, while NO2 hotspots were in the west and south. COD values of PMX demonstrated more results lower than the 0.2 cut off compared to GAPs; indicating high to moderate spatial homogeneity for PMX and moderate to high spatial heterogeneity for GAPs. Regarding CV approach, the spatial variabilities of air pollutants followed in the order of O3 (87.3%) > SO2 (65.2%) > CO (61.8%) > PM10–2.5 (52.5%) > PM2.5 (48.9%) > NO2 (48.1%) > PM10 (42.9%), which were mainly in agreement with COD results, except for NO2. COD values observed a statistically (P

Indoor/outdoor particulate matter (PM10, PM2.5, and PM1) and their water-soluble ions were measured in a retirement home and a school dormitory in Tehran, from May 2012 to January 2013. Hourly indoor/outdoor PM concentrations were measured using GRIMM dust monitors and 24-h aerosol samples were collected by low-volume air samplers. Water-soluble ions were determined using an ion chromatography (IC) instrument. Although the mean outdoor PM concentrations in both sampling sites were almost equal, the mean indoor PM10 in the school dormitory was approximately 1.35 times higher than that in the retirement home. During a Middle Eastern dust storm, the 24-h average PM10, PM2.5, and PM1 concentrations were respectively 3.4, 2.9, and 1.9 times as high as those in normal days outdoors and 3.4, 2.8, and 1.6 times indoors. The results indicated that secondary inorganic aerosols were the dominant water-soluble ions of indoor and outdoor PM. We found that the smaller the particle, the higher the percentage of secondary inorganic aerosols. Except for PM10 in the school dormitory, strong correlations were found between indoor and outdoor PM. We estimated that nearly 45% of PM10, 67% of PM2.5, and 79% of PM1 in the retirement home, and 32% of PM10, 76% of PM2.5, and 83% of PM1 in the school dormitory originated from outdoor environment.

Effect of PM10, PM2.5, andPM1 on blood markers in a panel of elderly subjects. BACKGROUND: Systemic inflammation biomarkers have been associated with risk of cardiovascular morbidity and mortality. ...

In this study, atmospheric concentrations of particulate-bound polycyclic aromatic hydrocarbons (PAHs) in Tehran megacity were determined to investigate the concentration, distribution, and sources of PAHs in PM10. The health risk from exposure to airborne BaPeq through inhalation pathway was also assessed. Toxic equivalency factors (TEFs) approach was used for quantitative risk estimate, and incremental lifetime cancer risk (ILCR) was calculated. PM10 samples were collected at ten sampling locations during the summer 2013 and winter 2014 by using two independent methods of field sampling. The PM10 concentration in winter (89.55 ± 15.56 μg m(-3)) was 1.19 times higher than that in summer (75.42 ± 14.93 μg m(-3)). Sixteen PAHs were measured with the total average concentrations of PAHs ranged from 56.98 ± 15.91 to 110.35 ± 57.31 ng m(-3) in summer and from 125.87 ± 79.02 to 171.25 ± 73.94 ng m(-3) in winter which were much higher than concentrations measured in most similar studies conducted around the world. Molecular diagnostic ratios were used to identify PAH emission sources. The results indicated that gasoline-driven vehicles are the major sources of PAHs in the study area. Risk analysis showed that the mean and 90 % probability estimated inhalation ILCRs were 7.85 × 10(-6) and 16.78 × 10(-6), respectively. Results of a sensitivity analysis indicated that BaP concentration and cancer slope factor (CSF) contributed most to effect on ILCR mean.

Concentration of particulate matter (PM10 and total suspended particulate (TSP)) and their elemental constituents were measured to identify the major sources of elements in urban and industrial suburban sites in Tabriz, Iran, from September 2012 to June 2013. TSP and PM10 samples were collected using high-volume samplers. Concentrations of 31 elements in aerosols and crustal soil were determined by ICPMS. The most abundant detected metals in the urban sampling sites were Al (217.5-4019.9 ng m(-3)), Fe (272.5-7658.0 ng m(-3)), Pt (4.7-1994.4 ng m(-3)), and P (13.6-2054.8 ng m(-3) (for TSP and Al (217.6-3687.3 ng m(-3)), Fe (197.1-3724.9 ng m(-3)), Pt (65.9-2054.5 ng m(-3)), and P (11.0-756.6 ng m(-3)( for PM10. In the suburban sampling site, the most abundant detected metals were Al (2083.0-9664.0 ng m(-3)), Fe (360.0-7221.5 ng m(-3)), P (229.4-870.5 ng m(-3)), and Ti (137.3-849.7 ng m(-3)) for TSP and Al (218.5-4179.6 ng m(-3)), Fe (106.3-2005.1 ng m(-3)), P (251.9-908.4 ng m(-3)), and Ba (10.6-584.9 ng m(-3)) for PM10. For the crustal soil, the most abundant detected elements included Al (60,088-60,694 ppm), Fe (19,886-20,474 ppm), Ti (894-3481 ppm), and Si (365-4246 ppm). Key emission sources were identified, and the concentrations contributed from individual sources were estimated. Enrichment factor (EF) explaining a preponderance of the variance in the data was applied to the datasets. EF calculations revealed that non-crustal trace elements were more enriched in the urban than suburban sampling sites. Results of the factor analysis on the elements showed that emissions from road traffic (involving oil and fuel combustions by vehicles, platinum group elements from vehicle exhaust, and resuspension of particulate matter from polluted soil) and construction dust from nearby construction sites and electricity generation plant were the major contributors of anthropogenic metals at ambient atmosphere in Tabriz. Results of this study elucidated the need for developing pollution control strategy, especially vehicle exhaust control, and creating green spaces around the city.

Bioaerosol concentration was measured in wastewater treatment units in south of Tehran, the largest wastewater treatment plant in the Middle East. Active sampling was carried out around four operational units and a point as background. The results showed that the aeration tank with an average of 1016 CFU/m(3) in winter and 1973 CFU/m(3) in summer had the greatest effect on emission of bacterial bioaerosols. In addition, primary treatment had the highest impact on fungal emission. Among the bacteria, Micrococcus spp. showed the widest emission in the winter, and Bacillus spp. was dominant in summer. Furthermore, fungi such as Penicillium spp. and Cladosporium spp. were the dominant types in the seasons. Overall, significant relationship was observed between meteorological parameters and the concentration of bacterial and fungal aerosols.

In the present work, we investigated the characteristics of polycyclic aromatic hydrocarbons (PAHs) and metal(loid)s in indoor/outdoor PM10, PM2.5, and PM1 in a retirement home and a school dormitory in Tehran from May 2012 to May 2013. The results indicated that the annual levels of indoor and outdoor PM10 and PM2.5 were much higher than the guidelines issued by the World Health Organization (WHO). The most abundant detected metal(loid)s in PM were Si, Fe, Zn, Al, and Pb. We found higher percentages of metal(loid)s in smaller size fractions of PM. Additionally, the results showed that the total PAHs (ƩPAHs) bound to PM were predominantly (83-88%) found in PM2.5, which can penetrate deep into the alveolar regions of the lungs. In general, carcinogenic PAHs accounted for 40-47% of the total PAHs concentrations; furthermore, the smaller the particle size, the higher the percentage of carcinogenic PAHs. The percentages of trace metal(loid)s and carcinogenic PAHs in PM2.5 mass were almost twice as high as those in PM10. This can most likely be responsible for the fact that PM2.5 can cause more adverse health effects than PM10 can. The average BaP-equivalent carcinogenic (BaP-TEQ) levels both indoors and outdoors considerably exceeded the maximum permissible risk level of 1 ng/m(3) of BaP. The enrichment factors and diagnostic ratios indicated that combustion-related anthropogenic sources, such as gasoline- and diesel-fueled vehicles as well as natural gas combustion, were the major sources of PAHs and trace metal(loid)s bound to PM.

Numerous studies have shown associations between air pollution and health effects on human. The aims of the present study were to provide quantitative data on variation of atmospheric particulate matter (PM) concentration and the impact of PM on the health of people living in Tabriz city. The approach proposed by the World Health Organization (WHO) was applied using the AirQ 2.2.3 software developed by the WHO European Centre for Environment and Health, Bilthoven Division. The concentration of particulate matter were measured at urban and industrial suburban sites in Tabriz, Iran, from September 2012 to June 2013. TSP and PM10 samples were collected using high volume samplers. PM2.5 and PM1 were measured by Haz-Dust EPAM-5000 particulate air monitors. The annual average concentrations of TSP, PM10, PM2.5, and PM1 in the urban site were 142.2 ± 76.3, 85.3 ± 43.9, 39 ± 19.1, and 28.4 ± 14.9 μg/m3 (mean ± SD), respectively. Also in industrial suburban, the total average concentrations of TSP, PM10, PM2.5, and PM1 were measured as 178.7 ± 52.7, 109.9 ± 30.2, 40.0 ± 10.9, and 31.4 ± 9.1 μg/m3, respectively. The PM10/TSP ratio for the whole study period ranged between 0.35-0.91 and 0.32-0.79 in the urban and suburban sites, respectively. Total mortalities associated with TSP, PM10 and PM2.5 concentrations were 327, 363, and 360, respectively. Furthermore, the cardiovascular mortalities for TSP and PM10 were 202 and 227 individual, respectively. According to the attributable respiratory mortalities of 99 and 67 associated respectively with TSP and PM10, it is clear that cardiovascular mortality resulted from PM might attributed to total mortality. The maximum 24-hour concentration of PM was observed during winter followed by autumn and the lowest one was during spring.