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Early-life arsenic (As) exposure is a particular health concern. However, it is unknown if As ingested early in life is more readily absorbed from the gastrointestinal (GI) tract, i.e., higher in oral bioavailability. Here, weanling (3-week) and adult (6-week-old) female mice were exposed to arsenate in the diet (10 mu g g-1) over a 3-week period with As oral bioavailability estimated using As urinary excretion as the bioavailability endpoint. The As urinary excretion factor was 1.54-fold higher in weanling mice compared to adult mice (82.2 +/- 7.29 versus 53.1 +/- 3.73%), while weanling mice also showed 2.28-, 1.50-, 1.48-, and 1.89-fold higher As concentration in small intestine tissue, blood, liver, and kidneys, demonstrating significantly higher As oral bioavailability of early-life exposure. Compared to adult mice, weanling mice significantly differed in gut microbiota, but the difference did not lead to remarkable differences in As biotransformation in the GI tract or tissue and in overall gut metabolite composition. Although the expression of several metabolites (e.g., atrolactic acid, hydroxyphenyllactic acid, and xanthine) was up-regulated in weanling mice, they had limited ability to elevate As solubility in the intestinal tract. Compared to adult mice, the intestinal barrier function and intestinal expression of phosphate transporters responsible for arsenate absorption were similar in weanling mice. However, the small intestine of weanling mice was characterized by more defined intestinal villi with greater length and smaller width, providing a greater surface area for As to be absorbed across the GI barrier. The results highlight that early-life As exposure can be more readily absorbed, advancing the understanding of its health risk. Refereed/Peer-reviewed

OBJECTIVE Neurofibromatosis type 2 (NF2) is a rare autosomal dominant syndrome associated primarily with bilateral vestibular schwannomas (VSs). Conventional surgical or radiosurgical treatments for VS in NF2 usually result in high risks of hearing loss and facial nerve impairment, while there is no validated medical option to date. This single-institution phase II study evaluated the efficacy and safety of icotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, in patients with NF2 and progressive VS. METHODS Icotinib was administered daily at 375 mg orally in a continuous 28-day course for up to 12 courses. The primary endpoint of the study was radiographic response assessed by brain MRI using 3D volumetric tumor analysis and defined as a ≥ 20% decrease in VS volume. Hearing function was evaluated as a secondary endpoint, with response defined as a statistically significant increase in word recognition scores. RESULTS Ten eligible patients with a mean age of 23.8 years were enrolled. One patient (10%) with bilateral tumors experienced an objective radiographic response (−23.58% and −22.01%). Three (43%) of 7 patients met the hearing response criteria. At 12 months, the estimated progression-free survival was 82.0% (95% CI 42.3%–95.5%) for volumetric progression and 69.2% (95% CI 37.3%−87.2%) for hearing progression. Common mild to moderate adverse events included rash (90%), diarrhea (50%), myalgia (20%), and nausea/gastrointestinal pain (20%). CONCLUSIONS Icotinib carries minor toxicity and is associated with radiographic and hearing responses in patients with NF2 and progressive VS.

Glioblastoma (GBM) is the most frequent tumor in the central nervous system. Long non-coding RNAs (lncRNAs) have been widely accepted as essential participators in cancer progression. Nonetheless, the specific role and mechanism of lncRNA SRY-box transcription factor 2 overlapping transcript (SOX2-OT) in GBM have not been studied. We evaluated expression levels of SOX2-OT, miR-192-5p and Ras-related protein Rab-2A (RAB2A) in GBM cells via qRT-PCR. To investigate the roles of SOX2-OT in GBM cells, CCK-8, JC-1, EdU, and western blot assays were performed. The connection among SOX2-OT, miR-192-5p and RAB2A in GBM cells was explored through pull down, luciferase reporter, and RIP assays. Western blot and qRT-PCR were employed to analyze the activity of extracellular-signal-regulated kinase (ERK) signaling pathway. SOX2-OT expression was higher in GBM cell lines than in normal cells. SOX2-OT knockdown repressed proliferation and promoted apoptosis of GBM cells. Mechanism assays revealed that SOX2-OT could sponge miR-192-5p. Moreover, RAB2A was certified to be the target gene of miR-192-5p. Overexpression of RAB2A reversed the repressive function of SOX2-OT knockdown on GBM cell growth. Furthermore, SOX2-OT activated ERK signaling pathway in GBM cells. SOX2-OT regulated miR-192-5p/RAB2A axis and ERK pathway to promote GBM cell growth.

Refereed/Peer-reviewed Microplastics exposure is a new human health crisis. Although progress in understanding health effects of microplastic exposure has been made, microplastic impacts on absorption of co-exposure toxic pollutants such as arsenic (As), i.e., oral bioavailability, remain unclear. Microplastic ingestion may interfere As biotransformation, gut microbiota, and/or gut metabolites, thereby affecting As oral bioavailability. Here, mice were exposed to arsenate (6 μg As g−1) alone and in combination with polyethylene particles of 30 and 200 μm (PE-30 and PE-200 having surface area of 2.17 × 103 and 3.23 × 102 cm2 g−1) in diet (2, 20, and 200 μg PE g−1) to determine the influence of microplastic co-ingestion on arsenic (As) oral bioavailability. By determining the percentage of cumulative As consumption recovered in urine of mice, As oral bioavailability increased significantly (P < 0.05) from 72.0 ± 5.41% to 89.7 ± 6.33% with PE-30 at 200 μg PE g−1 rather than with PE-200 at 2, 20, and 200 μg PE g−1 (58.5 ± 19.0%, 72.3 ± 6.28%, and 69.2 ± 17.8%). Both PE-30 and PE-200 exerted limited effects on pre- and post-absorption As biotransformation in intestinal content, intestine tissue, feces, and urine. They affected gut microbiota dose-dependently, with lower exposure concentrations having more pronounced effects. Consistent with the PE-30-specific As oral bioavailability increase, PE exposure significantly up-regulated gut metabolite expression, and PE-30 exerted greater effects than PE-200, suggesting that gut metabolite changes may contribute to As oral bioavailability increase. This was supported by 1.58–4.07-fold higher As solubility in the presence of up-regulated metabolites (e.g., amino acid derivatives, organic acids, and pyrimidines and purines) in the intestinal tract assessed by an in vitro assay. Our results suggested that microplastic exposure especially smaller particles may exacerbate the oral bioavailability of As, providing a new angle to understand health effects of microplastics.

Meningiomas are the most common benign intracranial tumors and frequently present with a gradual onset of neurological deficits; conversely, their acute presentation with hemorrhagic onset appears to be a rare event. Nonetheless, as early surgical evacuation is the foundation of treatment, a timely diagnosis of this rare type of intracranial hemorrhage is necessary. The purpose of the present single-center study was to investigate the radiological characteristics and propose a new bleeding classification for guiding the diagnosis and treatment. A total of 19 patients consecutively diagnosed with hemorrhagic meningioma were enrolled in this retrospective study. Intracranial extra-axial mass, tumor-associated hemorrhage and peritumoral brain edema were the three main radiological features of the hemorrhagic meningiomas. The site of tumor-associated hemorrhage included the peritumoral space, subarachnoid space, subdural space, brain parenchyma and/or intratumor region. Based on the anatomical relationship between meningioma and hematoma, the spontaneous hemorrhage stemming from meningiomas was further summarized into three bleeding patterns involving purely intratumoral hemorrhage (type I), purely extratumoral hemorrhage (type II) and combined intra/extratumoral hemorrhage (type III); furthermore, the type III hemorrhage usually came from type I bleeding that extended into the surrounding regions. The symptoms in type I patients were generally mild and early surgery was performed following adequate preoperative evaluations. The symptoms in type II patients were mild in certain cases and moderate to severe in others, so early or emergency surgery was chosen according to the clinical status of the patient. Almost all type III patients had moderate to severe symptoms and these patients usually required emergency surgery. In addition, patients with different bleeding types may have different pathological mechanisms underlying the tumor bleeding. Apart from being convenient for diagnosis, this concise and practical bleeding classification may aid in the selection of the treatment strategy and facilitate the understanding of the associated mechanisms.

Background Abdominal cerebrospinal fluid (CSF) pseudocyst is an uncommon but important complication of ventriculoperitoneal (VP) shunts. While individual articles have reported many cases of abdominal CSF pseudocyst following VP shunts, no case of a hemorrhagic abdominal pseudocyst after VP shunts has been reported so far. Case presentation This article reports a 68-year-old woman with a 4-month history of progressive abdominal pain and distention. She denied any additional symptoms. A VP shunt was performed 15 years earlier to treat idiopathic normal pressure hydrocephalus and no other abdominal surgery was performed. Physical examination revealed an elastic palpable mass in her right lower abdomen, which was dull to percussion. Abdominal computed tomography (CT) scan indicated a large cystic collection of homogenous iso-density fluid in the right lower abdominal region with clear margins. The distal segment of the peritoneal shunt catheter was located within the cystic mass. Abdominal CSF pseudocyst was highly suspected as a diagnosis. Laparoscopic cyst drainage with removal of the whole cystic mass was performed, 15-cm cyst which found with thick walls and organized chronic hematic content. No responsible vessel for the cyst hemorrhage was identified. No further shunt revision was placed. Histological examination showed that the cyst wall consisted of outer fibrous tissue and inner granulation tissue without epithelial lining, and the cystic content was chronic hematoma. The patient had an uneventful postoperative course and remained asymptomatic for 8-mo follow-up. Conclusion To the best of our knowledge, this is the first report of hemorrhagic onset in the abdominal pseudocyst following VP shunt. Such special condition can accelerate the appearance of clinical signs of the abdominal pseudocyst after VP shunts, and its mechanisms may be similar to the evolution of subdural effusion into chronic subdural hematoma (CSDH).

Standard reference materials (SRMs) have been commonly used to perform quality assurance and quality control (QA/QC) in soil total metal concentration analyses or bioaccessibility assessment. In this study, 10 experimenters from 4 laboratories determined bioaccessibility of lead (Pb) in 4 widely-used SRMs (NIST 2710a, NIST 2587, BGS 102, and GBW 07405). Based on the gastric phase (GP) of the unified BARGE bioaccessibility method (UBM) and the Solubility Bioavailability Research Consortium procedure (SBRC), Pb bioaccessibility in SRMs was compared within and between laboratories to assess their intra-laboratory repeatability and inter-laboratory reproducibility. Lead bioaccessibility was 14.1 ± 2.44%-101 ± 2.48% in the 4 SRMs. The values were in vivo validated based on a mouse model in previous studies (R

Nine previously undescribed compounds including three sesquiterpenoids, three iridoids, two monoterpenoids and a furan fatty acid, along with seventeen known ones, were isolated from the water decoction of roots and rhizomes of Valeriana officinalis L. Structure elucidation of the twenty-six compounds were accomplished by analysis of the extensive spectroscopic data, and the absolute configurations of the nine previously undescribed ones were established by NOESY experiment and the electronic circular dichroism (ECD) simulations. Among them, β-patchoulene-8-O-β-D-glucopyranoside, 11-methoxyl-viburtinal, and protocatechuic acid showed anti-neuroinflammatory potentials by significantly inhibiting the secretion of nitric oxide (NO) on BV-2 cells upon LPS stimulation (p 0.001) without affecting the cell viability.

Treatment of schwannomas in patients with neurofibromatosis type 2 (NF2) is extremely unsatisfactory, and innovative therapeutic approaches are urgently needed. However, the lack of clinically relevant NF2-associated schwannoma models has severely hampered drug discovery in this rare disease. Here we report the first establishment and characterization of patient-derived xenograft (PDX) and cell line models of NF2-associated schwannoma, which recapitulates the morphological and histopathological features of patient tumors, retain patient NF2 mutations, and maintain gene expression profiles resembling patient tumor profiles with the preservation of multiple key signaling pathways commonly dysregulated in human schwannomas. Using gene expression profiling, we identified elevated PI3K/AKT/mTOR networks in human NF2-associated vestibular schwannomas. Using high-throughput screening of 157 inhibitors targeting the PI3K/AKT/mTOR pathways in vitro, we identified a dozen inhibitors (such as BEZ235, LY2090314, and AZD8055) with significant growth-suppressive effects. Interestingly, we observed that three cell lines displayed differential therapeutic responses to PI3K/AKT/mTOR inhibitors. Furthermore, we demonstrated that two orally bioavailable inhibitors, AZD8055 and PQR309, suppressed NF2-associated schwannoma growth both in vitro and in vivo. In conclusion, our novel patient-derived models of NF2-associated schwannoma closely mimic the phenotypes and genotypes of patient tumors, making them reliable preclinical tools for testing novel personalized therapies. © 2022 The Pathological Society of Great Britain and Ireland.

Ascoviruses are fatal double-stranded DNA viruses with a special pathogenesis in which cells are converted into vesicles with virions. Several closely related ascovirus isolates that shared more than 90% genomic DNA identity showed different pathogenic courses in previous studies. To investigate the pathogenic differences between the related ascovirus isolates, Heliothis virescens ascovirus 3i (HvAV-3i) and Heliothis virescens ascovirus 3j (HvAV-3j) were used to inoculate four noctuid pest species (Helicoverpa armigera, Mythimna separata, Spodoptera frugiperda, and Spodoptera litura), and the pathogenic indexes were recorded. The mortality of HvAV-3i infected H. armigera and S. frugiperda was approximately 60%, while the other HvAV-infected larvae had mortality rates above 90%. The maximum lethal dilution ratios of HvAV-3i in H. armigera, M. separata, S. frugiperda, and S. litura were 1.90 × 10

This paper designs a multi robot formation control and tracking algorithm based on improved leader follower in wireless sensor environment. Whether a static or moving system can maintain a stable state or an ideal motion mode under all kinds of accidental or continuous disturbances is a problem that the algorithm proposed in this chapter has always been concerned about. For the field of mobile robot formation control, it is necessary to comprehensively analyze the influence of various factors on the stability of mobile robot formation after establishing the nonlinear incremental kinematic model of mobile robot. In this section, the overall and unified mobile robot formation will be established.

The main task of mobile robot path planning is according to the environment model, the mobile robot finds a collision free path from the starting coordinate point to the target coordinate point in the motion space according to one or some optimization criteria, such as the minimum work cost, the shortest walking route, the shortest walking time and so on, Make the robot reach the destination safely. At present, mobile robot path planning methods can be divided into three categories according to the working mode. One is path planning based on environment model, which can deal with the path planning under the condition of completely knowing the position and automatically shape of obstacles. Specific methods such as a topological graph method [1–2], etc.; The second one is the local path planning method based on sensor information. Including: artificial potential field method [3], fuzzy logic method [4], etc.; The third one is the behavior-based path planning method [5–6], The paper shows Verification and analysis of two-dimensional path planning objective function optimization based on classical particle swarm optimization algorithm.

Treatment for vestibular schwannoma (VS) in patients with neurofibromatosis type 2 (NF2) is extremely challenging due to the high risk of hearing loss. The aim of this study was to develop nomograms for the prediction of useful hearing loss in patients with NF2.The nomogram was based on a retrospective study of 111 NF2 patients who underwent resection of large VS ( 2 cm) at Beijing Tiantan Hospital between 2011 and 2018. The utility of the proposed nomogram models was evaluated by receiver operating characteristic (ROC) curve, area under ROC curve (AUC), and calibration curve. The results were validated using a prospective cohort study on 33 patients consecutively enrolled at the same institution from 2019 to 2021.On multivariate analysis of the primary cohort, large tumour size ( 3 cm) and long duration of symptoms ( 24 months) were independent risk factors for preoperative useful hearing loss (AAO-HNS Class D) (P = 0.001 and P = 0.011, respectively), while large tumour size ( 3 cm), poor hearing (Class C), and lobular growth were significantly related to postoperative useful hearing loss (P 0.001, P = 0.031 and P = 0.033, respectively). Factors derived from multivariable analysis were all assembled into the nomogram. The calibration curve for probability of hearing loss showed good agreement between predictions by nomogram models and actual observation. The ROC curves showed good predictive accuracy of the nomogram models in both cohorts (AUC: 0.708 to 0.951).The proposed nomograms resulted in accurate predictions of hearing outcomes for patients with NF2.

2,6-dichlorobenzoquinone (2,6-DCBQ) is an emerging disinfection byproduct frequently detected in drinking water. Previous studies have indicated that 2,6-DCBQ causes oxidative stress damage in some live systems, but this has yet to be tested in vivo in mammals. In the present study, adult mice were exposed to 2,6-DCBQ for 30 d via gavage at 0 ~ 100 mg kg− 1 with the responses of antioxidant enzymes (superoxide dismutase [SOD] and catalase [CAT]), key oxidative stress response genes (Heme oxygenase-1 [HO-1], NADPH quinone oxidoreductase 1 [NQO1] and glutamate-L-cysteine ligase catalytic subunit [GCLC]) in the Nrf2-keap1 pathway, and lipid peroxidation (malonaldehyde, MDA) as an indicator of oxidative damage being measured. Our results indicated that 2,6-DCBQ decreased the activities of SOD and CAT, repressed transcription of key genes in the Nrf2-keap1 pathway, and caused measurable oxidative damage. These results reveal the impact of 2,6-DCBQ in a model mammalian system and are key to understanding the potential impacts of 2,6-DCBQ in humans.

Background: Delayed intracerebral hemorrhage (DICH) secondary to ventriculoperitoneal (VP) shunt is considered to be a potentially severe event, however, little is known about the risk factors and underlying mechanisms. This study aimed to investigate the association between NLRR (a ratio of postoperative neutrophil-to-lymphocyte ratio to preoperative neutrophil-to-lymphocyte ratio) and DICH secondary to VP shunt.Methods: We performed a retrospective review of patients who underwent VP shunt between January 2016 and June 2020. Multivariable logistic regression analysis was used to assess the association of DICH and NLRR. Then patients were divided into two groups according to the optimal cut-off point of NLRR, propensity score matching (PSM) method was performed to reconfirm the result.Results: A total of 130 patients were enrolled and DICH occurred in 29 patients. Elevated NLRR (odds ratio [OR], 2.774; 95% confidence interval [CI], 1.372-5.609; P2.05 had much higher incidence of DICH (OR, 11.25; 95%CI, 1.35-93.50; p=0.025; PSM cohort, n=82). Conclusions: Our finding suggested that DICH following VP shunt was not a rare complication and elevated NLRR could independently predict DICH. Inflammatory responses might play an important role in the development of DICH following VP shunt.

Background To investigate the effect of brachial–ankle pulse wave velocity (baPWV) on new-onset acute myocardial infarction (AMI). Methods A retrospective cohort study was performed for the subjects who underwent baPWV examination during the follow-up of Kailuan Study Cohort from 2010 to 2017. The observation subjects were divided into 3 groups based on the levels of baPWV: Results A total of 41,405 subjects were included in the study. During 2.66 (1.07–5.39) years’ follow-up, 150 new-onset AMI cases were observed. The incidence density of AMI in 3 groups was 3.69, 12.79, and 26.65 per 10,000 person-years, respectively. Log-rank test result showed the cumulative AMI incidence increased gradually from the subjects with the lowest baPWV to those with the highest baPWV (P < 0.05). Compared with subjects with baPWV Conclusions The increased baPWV is a risk factor for new-onset AMI.

Refereed/Peer-reviewed Ingestion of metal-contaminated soils poses risks to human health. To accurately assess the risks, in vitro assays have been developed to measure metal bioaccessibility. However, they often differ considerably in gastrointestinal fluid components and assay parameters, leading to inconsistent bioaccessibility results. As such, in vitro assays need to be validated against in vivo bioassays based on in vivo-in vitro correlations (IVIVCs). To help researchers to select the best in vitro assay and increase the robustness of the IVIVCs, there is a need to review and compile existing data. In this review, we focus on three metals (As, Pb, and Cd), five common in vitro assays (SBRC, UBM, IVG, DIN, and PBET), and two in vivo bioassays (mouse and swine models). Specifically, we 1) discuss variations in metal bioaccessibility measurements among different in vitro assays, 2) identify the roles of major gastrointestinal fluid constitutes and assay parameters in affecting metal bioaccessibility, 3) summarize weaknesses associated with existing IVIVCs, and 4) establish new IVIVCs using pooled soil samples from different studies. In addition, future research directions are highlighted, including better understanding of the roles of gastrointestinal fluid components, improving in vitro assays to better correlate with in vivo bioassays, expanding bioaccessibility measurements using different in vitro assays, validation of IVIVCs using independent soils, assessing the reliability of in vitro assays in remediated soils, and addressing the mechanisms behind IVIVCs.

In the process of evacuation of pedestrian flow, the dynamic strategy choosing among pedestrians greatly influence evacuation efficiency. To address the problem of this dynamic evolutionary game, the direction fuzzy visual field of a moving pedestrian is defined, which fully takes into account the differences between pedestrians in terms of visual field selection. Based on the direction fuzzy visual field, this paper constructs a dynamic evolutionary game model and analyzes the formation and dynamic development of pedestrian flow strategy choosing. It presents the payoff matrix in which heterogeneous pedestrians adjust their strategy according to different payoff. The study results show that the model can effectively demonstrate macroscopic self-organization phenomena of pedestrian flow. The dynamic game equilibrium is related to the radius of the direction fuzzy visual field, the cost of strategic adjustment, the pedestrian density, and the system scale. The radius of the direction fuzzy visual field is bigger, the pedestrians can have more information, and they more likely to adopt competition strategy. There is a critical value for pedestrian density. When pedestrian density is greater than this critical value, the pedestrians will feel crowded and tend to adopt competition strategy. The cost of strategic adjustment is smaller, the pedestrians are more likely to adopt cooperation strategy, a few competitors will gather near the walls. When the cost of strategic adjustment is bigger, the pedestrians tend to adopt competition strategy, a small number of cooperators are gathering near the walls. Therefore, the walls play a very important role in pedestrian flow evacuation. The cellular system scale is bigger, pedestrians are more likely to cooperate.

Animal bioassays have been developed to estimate oral relative bioavailability (RBA) of metals in soil, dust, or food for accurate health risk assessment. However, the comparability in RBA estimates from different labs remains largely unclear. Using 12 soil and soil-like standard reference materials (SRMs), this study investigated variability in lead (Pb) and arsenic (As) RBA estimates employing a mouse bioassay in 3 labs at Nanjing University, University of Jinan, and Shandong Normal University. Two performances of the bioassay at Nanjing University in 2019 and 2020 showed reproducible Pb and As RBA estimates, but increasing the number of mouse replicates in 2020 produced more precise RBA measurements. Although there were inter-lab variations in diet consumption rate and metal accumulation in mouse liver and kidneys following SRM ingestion due to differences in diet composition, bioassays at 3 labs in 2019 yielded overall similar Pb and As RBA estimates for the 12 SRMs with strong linear correlations between each 2 of the 3 labs for Pb (R2 = 0.95–0.98 and slope = 0.85–1.02) and As RBA outcomes (R2 = 0.46–0.86 and slope = 0.56–0.79). The consistency in RBA estimates was attributed to the relative nature of the final bioavailability outcome, which might overcome the inter-lab variation in diet consumption and metal uptake in mice. These results increased the confidence of use of mouse bioassays in bioavailability studies. Refereed/Peer-reviewed

The spatiotemporal presence of overall disinfection by-products (DBPs) in two full-scale drinking water supply systems (DWSSs) were investigated using quantification of total organic halogen (TOX). The relationships of TOX with water quality parameters (especially the most regulated DBPs, trihalomethanes (THMs)) were also evaluated. The TOX levels ranged between 2.6 and 70.3 μg Cl/L and between 46.6 and 205.9 μg Cl/L in raw water and distribution water, respectively. The TOX concentration in water increased by an average of nine times after water treatment and varied slightly during distribution, suggesting that TOX in drinking water was mainly formed during chlorination disinfection rather than distribution. No clear seasonality in TOX level was observed. Positive correlations were found between raw water dissolved organic carbon (DOC) with an increase in TOX in treated water and between DOC level with TOX content in distributed water, emphasizing a key role of organics in TOX formation. Chloroform (TCM) was the dominant THM, followed by bromodichloromethane (BDCM) in the drinking water, and the levels of the other two measured THMs (dibromochloromethane and bromoform) were negligible. THM2 (sum of TCM and BDCM) made up average of 18% of the TOX, and was weakly correlated with TOX content (rs = 0.321; P

To understand how Cd in different fractions contributes to Cd bioaccessibility by in vitro assays, Cd bioaccessibility in 12 contaminated soils was determined by four assays (UBM, SBRC, IVG, and PBET) and correlated with different Cd fractions based on a sequential extraction scheme. The Cd bioaccessibility in the gastric phase (GP) was high (35–107%, averaging at 77%), implicating high risk to human health, while it decreased to 19–88% averaging at 47% in the intestinal phased (IP). From the GP to IP, the reduction of extractable Cd (0.45–48 mg kg−1) and Fe (118–3884 mg kg−1) showed significant correlation (R = 0.54–0.74) via UBM, SBRC, and IVG, suggesting co-precipitation with Fe and/or sorption onto Fe oxides maybe responsible for decrease in Cd bioaccessibility. Although Cd bioaccessibility varied among assays, their results show some consistency based on their correlation in the GP (R = 0.56–0.90) and IP (0.34–0.73, excluding UBM-IP and PBET-IP). Sequential extraction data show that Cd was primarily associated with the exchangeable fraction (E1; 7.05–72.9%, averaging 39.4%). The carbonate (C2; 6.86–44.8%, 21.9%) and Fe/Mn oxides fraction (F3; 12.5–53.6%, 28.2%) were similar, while organic (O4; 0.62–25.0%, 7.91%) and residual fraction (R5; 0.22–8.54%, 2.62%) were the lowest. Significant correlation (R = 0.59–0.88) between the first two fractions (E1+C2) and bioaccessible Cd suggest they were the main sources of bioaccessible Cd in those contaminated soils.

Seasonal changes in chemical compositions and source apportionment of PM