Presence of polycyclic aromatic hydrocarbons and persistent organochlorine pollutants in human Milk: Evaluating their levels, association with Total antioxidant capacity, and risk assessment.

Breastfeeding provides numerous health benefits for both infants and mothers, promoting optimal growth and development while offering protection against various illnesses and diseases. This study investigated the levels of polychlorinated biphenyls (PCB), organochlorine pesticides (OCP) and polycyclic aromatic hydrocarbons (PAH) in human milk sampled in Zadar (Croatia). The primary objectives were twofold: firstly, to evaluate the individual impact of each compound on the total antioxidant capacity (TAC) value, and secondly, to assess associated health risks. Notably, this study presents pioneering and preliminary insights into PAH levels in Croatian human milk, contributing to the limited research on PAH in breast milk worldwide. PCB and OCP levels in Croatian human milk were found to be relatively lower compared to worldwide data. Conversely, PAH levels were comparatively higher, albeit with lower detection frequencies. A negative correlation was established between organic contaminant levels and antioxidative capacity, suggesting a potential link between higher antioxidative potential and lower organic contaminant levels. Diagnostic ratio pointed towards traffic emissions as the primary source of the detected PAH. The presence of PAH suggests potential health risk, underscoring the need for further in-depth investigation.

An assessment of the (anti)androgenic properties of hexachloronaphthalene (HxCN) in male rats.

The persistent organic pollutants (POPs) defined by the Stockholm Convention include polychlorinated naphthalenes (PCNs); of these, the most toxic, persistent, abundant, dioxin-like congeners found in human tissues are the hexachloronaphthalenes (HxCNs). Recent research also indicates that PCNs may disrupt hormonal homeostasis. The aim of this study was to evaluate the (anti)androgenic action of HxCN. Immature, castrated male Wistar rats were exposed per os to HxCN in corn oil at daily doses ranging from 0.3 to 3.0 mg kg-1 for 10 days. According to the OECD 441 protocol (Hershberger Bioassay), the anti-androgenic assay groups were co-exposed with testosterone propionate (TP), while the androgenic groups were not. TP was used as the reference androgen (subcutaneous daily doses of 0.4 mg kg-1), and flutamide (FLU) as the reference antiandrogen (per os daily doses of 3.0 mg kg-1). Five assessory sex tissues (ASTs) were weighed: ventral prostate, seminal vesicles, levator ani-bulbocavernosus muscle (LABC), Cowper's glands and glans penis. HxCN + TP significantly decreased the weight of the ventral prostate and seminal vesicle indicating an anti-androgenic action via 5α-reductase inhibition. These weight changes were also accompanied by abnormalities in cell morphology and hormonal disturbances: lowered levels of the testosterone and thyroid hormones thyroxine and triiodothyronine. Disturbances were also noted in the lipid profile, viz. total cholesterol, triglycerides and high-density lipoprotein and non-HDL fraction content. However, the direction of these changes differed depending on the size of the HxCN dose. No dose-effect relationship was noted for most of the obtained results; as such, exposure to even small HxCN doses run the risk of anti-androgenic effects in the general population, especially when encountered in combination with other POPs and endocrine-disrupting chemicals in the environment.

Optimization and uncertainty assessment of a gas chromatography coupled to Orbitrap mass spectrometry method to determine organic contaminants in blood: A case study of an endangered seabird.

Birds are excellent bioindicators of environmental pollution, and blood provides information on contaminant exposure, although its analysis is challenging because of the low volumes that can be sampled. The objective of the present study was to optimize and validate a miniaturized and functional extraction and analytical method based on gas chromatography coupled to Orbitrap mass spectrometry (GCOrbitrap-MS) for the trace analysis of contaminants in avian blood. Studied compounds included 25 organochlorine pesticides (OCPs), 6 polychlorinated biphenyls (PCBs), 8 polybrominated diphenyl ethers (PBDEs) and 15 polycyclic aromatic hydrocarbons (PAHs). Four extraction and clean-up conditions were optimized and compared in terms of efficiency, accuracy, and uncertainty assessment. Extraction with hexane:dichloromethane and miniaturized Florisil pipette clean-up was the most adequate considering precision and accuracy, time, and costs, and was thereafter used to analyse 20 blood samples of a pelagic seabird, namely the Bermuda petrel (Pterodroma cahow). This species, endemic to the Northwest Atlantic, is among the most endangered seabirds of the region that in the '60 faced a decrease in the breeding success likely linked to a consistent exposure to dichloro-diphenyl-trichloroethane (DDT). Indeed, p,p'-DDE, the main DDT metabolite, was detected in all samples and ranged bewteen 1.13 and 6.87 ng/g wet weight. Other ubiquitous compounds were PCBs (ranging from 0.13 to 6.76 ng/g ww), hexachlorobenzene, and mirex, while PAHs were sporadically detected at low concentrations, and PBDEs were not present. Overall, the extraction method herein proposed allowed analysing very small blood volumes (∼ 100 µL), thus respecting ethical principles prioritising the application of less-invasive sampling protocols, fundamental when studying threatened avian species.

First comprehensive assessment of dietary chlorinated paraffins intake and exposure risk for the rural population of the Tibetan Plateau, China.

Knowledge regarding the occurrence of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) in foodstuffs and their dietary exposure risks for rural Tibetan residents remains largely unknown. Herein, we collected main foodstuffs (including highland barley, vegetables, Tibetan butter, mutton, and yak beef) across the rural Tibetan Plateau and characterized the CP profiles and concentrations. The highest SCCPs concentrations were detected in Tibetan butter (geometric mean (GM): 240.6 ng/g wet weight (ww)), followed by vegetables (59.4 ng/g ww), mutton (51.4 ng/g ww), highland barley (46.3 ng/g ww), and yak beef (31.7 ng/g ww). For MCCPs, the highest concentrations were also detected in Tibetan butter (319.5 ng/g ww), followed by mutton (181.9 ng/g ww), vegetables (127.0 ng/g ww), yak beef (71.2 ng/g ww), and highland barley (30.3 ng/g ww). The predominant congener profiles of SCCPs were C13Cl7-8 in mutton and yak beef, C10Cl7-8 in Tibetan butter, and C10-11Cl6-7 in highland barley and vegetables. The predominant congener profiles of MCCPs were C14Cl7-9 in all sample types. Combined with our previous results of free-range chicken eggs, the median estimated daily intakes (EDIs) of SCCPs and MCCPs via diet for Tibetan rural adults and children was estimated to be 728.8 and 1853.9 ng/kg bw/day and 2565.6 and 5952.8 ng/kg bw/day, respectively. In the worst scenario, MCCPs might induce potential health risks for rural Tibetan population. To our knowledge, this is the first systematic dietary exposure research of SCCPs and MCCPs in the remote rural areas.

Organic contamination and multi-biomarker assessment in watersheds of the southern Brazil: an integrated approach using fish from the Astyanax genus.

We aimed to examine the responses of pollution biomarkers in feral fish from Astyanax genus collected at three hydrographic regions in southern Brazil and the capacity of these tools to differentiate between various levels of contamination. To achieve this, levels of organochlorine pesticides (liver), as well as the biomarkers AChE (muscle and brain), TBARS (liver), and EROD (liver) were assessed. Collections were conducted in four municipalities (Alegrete, Caraá, Lavras, and Santa Vitória) during 1 year, encompassing winter and summer. Fish from Alegrete were the most contaminated overall, but animals sampled in Caraá, and Lavras also displayed elevated levels of current-use pesticides. Elevated levels of endosulfans, DDTs, HCHs, and current-use pesticides were accompanied by elevated levels of TBARS in the liver. Conversely, fish from Santa Vitória exhibited the highest levels of PAHs, accompanied by elevated levels of EROD in the liver and reduced levels of AChE in muscle and brain. TBARS proved to be a reliable biomarker for assessing impacts arising from pesticide accumulation, while EROD and AChE served as valuable indicators of impacts resulting from PAHs accumulation. Ultimately, the results obtained in this study demonstrate the reliable use of the proposed biomarkers for tracking biological impacts stemming from aquatic pollution using feral Astyanax as biomonitoring species.

Short- and medium-chain chlorinated paraffins in breast milk in Shanghai, China: Occurrence, characteristics, and risk assessment.

As novel contaminants, short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) have been of great concern in the past several years. Shanghai was one of the provinces with the largest chlorinated paraffins (CPs) emission in China; nevertheless, there is currently little information on the human exposure to SCCPs and MCCPs, particularly MCCPs. In this study, 25 breast milk samples were collected in Shanghai from 2016 to 2017. The concentrations of SCCPs and MCCPs were determined using two-dimensional gas chromatography coupled with orbitrap high-resolution mass spectrometry (GC × GC-orbitrap-HRMS) to investigate their characteristics and assess the associated health risks for breast-fed infants. Compared with the previous studies in other areas, the current study presented the higher CPs concentrations, with median concentrations of SCCPs and MCCPs up to 771 and 125 ng/g lipid weight (lw), respectively. The exposure profiles of the CPs were characterized by C10 and Cl6-7 as the predominant congeners of SCCPs, while C14 and Cl7-9 were identified as the dominant groups of MCCPs. CP-42 and CP-52 were identified as potential sources of CPs found in breast milk samples collected in Shanghai. The concentrations of MCCPs exhibited a positive correlation (p value < 0.05) with the dietary consumption of meat and poultry. No significant positive correlations were observed for SCCPs and MCCPs with polychlorinated dibenzodioxins/furans (PCDD/Fs) congeners. A preliminary exposure assessment showed that SCCPs in breast milk potentially posed high risks to the breast-fed infants in Shanghai.

Sediment-water exchange and risk assessment of pesticidal persistent organic pollutants in Bharathappuzha and Periyar Riverine region along the Arabian Sea.

Considering the extensive agricultural practices along the perennial rivers, viz. Periyar and Bharathappuzha of Kerala in the southwest coast of India, the first comprehensive surveillance of new and legacy organochlorine pesticides (OCPs) in surface sediment was conducted. Further, the sediment-water exchange fluxes have been elucidated. Mean concentrations of total HCH, DDT and endosulfan were 0.84 ng/g, 0.42 ng/g and 0.30 ng/g for Bharathappuzha Riverine sediment (BRS) and 1.08 ng/g, 0.39 ng/g and 0.35 ng/g for Periyar Riverine sediment (PRS). The dominance α-HCH and ß-HCH isomers in PRS and BRS reflect the ongoing use of technical HCH in Kerala. The calculated KSW in both rivers was very low in comparison with other Indian rivers. The average log K'OC for all the detected OCPs in both the rivers was lower than the predicted log KOC in equilibrium indicating the higher adherence of OCPs to sediment. Furthermore, fugacity fraction (fs/fw) was < 1.0 for all OCPs confirming the net deposition of OCPs into the sediment. Sediment concentrations for each of the OCPs in PRS and BRS did not surpass the threshold effect level and probable effect level as stipulated by the Canadian Council of Ministry of the Environment Guidelines. In addition, all the sites of both rivers had sediment quality guideline quotient (SQGQ) values below 0.1 indicating the absence of significant biological and ecological risks.

Organohalogen compounds in a hotspot for chemical pollution: Assessment in free-ranging Atlantic spotted dolphins (Stenella frontalis).

The assessment of chemical pollution in free-ranging living mammals is viable using remote biopsies and portrays a comprehensive scenario of environmental health. The Southwestern Atlantic Ocean holds incredible biodiversity, but it is under the constant and invisible threat of persistent organic pollutants (POPs) of anthropogenic origin, such as pesticides, brominated flame retardants, and industrial-use compounds (e.g., PCBs). Thus, this study aimed to assess the bioaccumulation of POPs (PCBs, DDTs, HCB, mirex and PBDEs) and natural organobromine compounds (MeO-BDEs) using gas-chromatography coupled to mass spectrometry in biopsy samples of Atlantic spotted dolphins (Stenella frontalis, n = 20) that inhabit and forage both inside and in adjacent areas to degraded (Guanabara Bay) and conserved (Ilha Grande Bay) coastal bays in the Southeastern Brazil. Among the studied compounds, PCBs were predominant in the contamination profile with median concentration of 97.0 µg.g-1 lipid weight (lw), followed by the sum of the p,p' isomers of DDT, DDD, and DDE of 11.0 µg.g-1 lw, the brominated flame retardants PBDEs of 1.6 µg.g-1 lw, and the other organochlorine pesticides mirex of 0.78 µg.g-1 lw, and HCB of 0.049 µg.g-1 lw. The MeO-BDEs were detected with a median concentration of 22.8 µg.g-1 lw. 85 % of the Atlantic spotted dolphins analyzed in this study presented PCB concentration that exceeded even the less conservative threshold limits for adverse health effects (41 µg.g-1 lw). This study shows that despite the conservation status of preserved bays, cetacean species foraging in these locations are still under increased threat. Hence chemical pollution demands local and global efforts to be mitigated.

Spatial distribution and ecological risk assessment of short and medium chain chlorinated paraffins in water and sediments of river Ravi, Pakistan.

Short (SCCPs) and medium (MCCPs) chain chlorinated paraffins being the emerging organic pollutants have raised serious concerns due to their widespread use and related human health risks. However, their occurrence in aquatic bodies like rivers and associated damage to ecological integrity is yet unknown in some regions of the world. The current study is the first ever assessment of SCCPs and MCCPs in sediment and water of river Ravi, Pakistan. Spatial occurrence and associated ecological risks were investigated from sediments (n = 16) and composite water samples (n = 8) collected at eight locations along the stretch of river Ravi. The concentrations of SCCPs and MCCPs varied from below limit of detection (

[Exposure characteristics and health risk assessment of 97 typical chemical pollutants in human serum].

Rapid industrial and agricultural developments in China have led to the wide use and discharge of chemical products and pesticides, resulting in extensive residues in environmental media. These residues can enter the human body through various pathways, leading to high exposure risks and health hazards. Because the human body is exposed to a variety of chemical pollutants, accurately quantifying the exposure levels of these pollutants in the human body and evaluating their health risks are of great importance. In this study, the serum concentrations of 97 typical chemical pollutants of 60 adults in central China were simultaneously determined using solid-phase extraction coupled with gas chromatography-tandem mass spectrometry (SPE-GC-MS/MS). In this method, 200 µL of a serum sample was mixed with 10 µL of an isotope-labeled internal standard solution. The sample was vortexed and refrigerated overnight at 4 ℃. Each sample was then deproteinized by the addition of 200 µL of 15% formic acid aqueous solution and vortexed. The serum sample was loaded into a preconditioned Oasis® PRiME HLB SPE cartridge and rinsed with 3 mL of methanol-water (6∶1, v/v). The SPE cartridge was subsequently vacuumed. The analytes were eluted with 3 mL of dichloromethane followed by 3 mL of n-hexane. The eluent was concentrated to near dryness under a gentle nitrogen stream and reconstituted with 100 µL of acetone. The samples were determined by GC-MS/MS and separated on a DB-5MS capillary column (30 m×0.25 mm×0.25 µm) with temperature programming. The column temperature was maintained at 70 ℃ for 2 min, increased at a rate of 25 ℃/min to 150 ℃, increased at a rate of 3 ℃/min to 200 ℃, and then held for 2 min. Finally, the column temperature was increased at a rate of 8 ℃/min to 300 ℃ and maintained at this temperature for 8 min. The samples were detected in multiple-reaction monitoring (MRM) mode and quantitatively analyzed using the internal standard method. Multiple linear regression models were used to analyze the effects of demographic characteristics, lifestyle habits, and diet on the concentrations of the chemical pollutants in the serum samples, and known biomonitoring equivalents (BEs) and human biomonitoring (HBM) values were combined to compute hazard quotients (HQs) and hazard indices (HIs) and evaluate the health risks of single and cumulative exposures to the chemical pollutants. The results showed that the main pollutants detected in human serum were organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The detection rates of eight pollutants, including hexachlorobenzene (HCB) (100%), pentachlorophenol (PCP) (100%), p,p'-dichlorodiphenylene (p,p'-DDE) (100%), PCB-138 (100%), PCB-153 (98.3%), ß-hexachlorocyclohexane (ß-HCH) (91.7%), fluorene (Flu) (85.0%), and anthracene (Ant) (75.0%), were greater than 70%. The serum levels of ß-HCH were higher in females than in males, and age was positively correlated with exposure to p,p'-DDE, PCB-138, PCB-153, and ß-HCH. Increased exposure levels to p,p'-DDE and ß-HCH may be associated with a high frequency of meat intake, whereas increased exposure level to PCP may be associated with a high frequency of vegetable intake. The serum HQ of PCP was greater than 1 in 6.7% of the samples, and no risk was observed for HCB and p,p'-DDE exposure in the study population. Approximately 28.3% of the study subjects had HI values greater than 1. Overall, the general adult population in this region is widely exposed to a wide range of chemical pollutants, and gender, age, and diet are likely to be the main factors influencing the concentration of chemical pollutants. The health risk of single and compound exposures to chemical pollutants should not be ignored.

In vitro assessment of potential endocrine disrupting activities of chlorinated paraffins of various chain lengths.

The production of chlorinated paraffins (CPs) has risen in the past two decades due to their versatile industrial applications. Consequently, CPs are now widely detected in human food sources, the environment, and in human matrices such as serum, the placenta and breast milk. This raises concern about prenatal and postnatal exposure. While some studies suggest that certain short-chained CPs (SCCPs) may have endocrine disrupting properties, knowledge about potential endocrine disrupting potential of medium- (MCCP) and long-chained CPs (LCCPs) remains relativity sparse. Here, we used a panel of in vitro assays to investigate seven pure CPs and two technical mixtures of CPs. These varied in chain length and, chlorination degree. The in vitro panel covered androgen, estrogen, and retinoic acid receptor activities, transthyretin displacement, and steroidogenesis. One of the SCCPs inhibited androgen receptor (AR) activity. All SCCPs induced estrogen receptor (ER) activity. Some SCCPs and MCCPs increased 17ß-estradiol levels in the steroidogenesis assay, though not consistently across all substances in these groups. SCCPs exhibited the most pronounced effects in multiple in vitro assays, while the tested LCCPs showed no effects. Based on our results, some CPs can have endocrine disrupting potential in vitro. These findings warrant further examinations to ensure that CPs do not cause issues in intact organisms, including humans.

Remarkable Contamination of Short- and Medium-Chain Chlorinated Paraffins in Free-Range Chicken Eggs from Rural Tibetan Plateau.

Rapid social-economic development introduces modern lifestyles into rural areas, not only bringing numerous modern products but also new pollutants, such as chlorinated paraffins (CPs). The rural Tibetan Plateau has limited industrial activities and is a unique place to investigate this issue. Herein we collected 90 free-range chicken egg pool samples across the rural Tibetan Plateau to evaluate the pollution status of CPs. Meanwhile, CPs in related soils, free-range chicken eggs from Jiangxi, and farmed eggs from markets were also analyzed. The median concentrations of SCCPs (159 ng g-1 wet weight (ww)) and MCCPs (1390 ng g-1 ww) in Tibetan free-range chicken eggs were comparable to those from Jiangxi (259 and 938 ng g-1 ww) and significantly higher than those in farmed eggs (22.0 and 81.7 ng g-1 ww). In the rural Tibetan Plateau, the median EDI of CPs via egg consumption by adults and children were estimated to be 81.6 and 220.2 ng kg-1 bw day-1 for SCCPs and 483.4 and 1291 ng kg-1 bw day-1 for MCCPs, respectively. MCCPs might pose potential health risks for both adults and children in the worst scenario. Our study demonstrates that new pollutants should not be ignored and need further attention in remote rural areas.

Are We Justified in Modeling Human Exposure to Chlorinated Paraffin Mixtures Using the Average Properties of Congeners and Homologues?

Concern over human exposure to chlorinated paraffin (CP) mixtures keeps increasing. The absence of a comprehensive understanding of how human exposure varies with the physicochemical properties of CP constituents has hindered the ability to determine at what level of aggregation exposure to CPs should be assessed. We answer this question by comparing exposure predicted with either a "complex" method that utilizes isomer-specific properties or "simplified" methods that rely on median properties of congener, homologue, or short-/medium-/long-chain CP groups. Our results demonstrate the wide range of physicochemical properties across CP mixtures and their dependence on molecular structures. Assuming unit emissions in the environment, these variances translate into an extensive disparity in whole-body concentrations predicted for different isomers, spanning ∼11 orders of magnitude. CPs with 13-19 carbons and 6-10 chlorines exhibit the highest human exposure potential, primarily owing to moderate to high hydrophobicity and slow environmental degradation and biotransformation. Far-field exposure is dominant for most CP constituents. Our study underscores that using average properties of congener, homologue, or S/M/LCCP groups yields results that are consistent with those derived from isomer-based modeling, thus offering an efficient and practical framework for future risk assessments and human exposure studies of CPs and other complex chemical mixtures.

Assessment of chlorinated pesticide exposure to white-rumped vulture Gyps bengalensis in India.

Populations of the critically endangered white-rumped vulture (WRV) Gyps bengalensis have declined drastically due to the use of diclofenac for veterinary purposes in Indian subcontinent. Thirty-two dead WRVs collected from three states, namely Gujarat, Assam and Tamil Nadu in India between 2011 and 2014 were investigated to understand the role of diclofenac in the death, and the results were published. Furthermore, since organochlorine pesticides have been linked to long-term impact on populations in many species of birds across the globe, available tissues of 21 WRVs were tested also for six organochlorine pesticides (DDT, HCH, endosulfan, heptachlor, dieldrin and dicofol) and chlorpyrifos. All vultures were found to have had one or more detectable levels of pesticides in their tissues except one. Similarly, all the pesticides included in the study were detected in at least one of the vultures analysed. DDT (95.2%) was the most frequently detected pesticide followed by HCH (90.5%), and DDT (73.6%) contributed the most to the total pesticide load. Total pesticide load ranged between below detection limit (BDL) and 8753.4 ng/g. High levels of total pesticide load recorded in gut contents showed recent exposure to these legacy pesticides even long after their ban. However, it is perceived that studied pesticides' exposure to birds and their presence in the environment is in decreasing trend in India. Although, varying levels of pesticides were detected, all of which were below the levels reported to be toxic, and also reported earlier in the same species in India. Recorded levels may not create a problem to vultures unlike diclofenac; nevertheless, as continued exposure to the pesticides studied may lead to sub lethal effects in birds, it is prudent to monitor these pesticides along with new generation pesticides and NSAIDs in the critically endangered white-rumped vulture in India, towards its conservation.

Placental concentrations of xenoestrogenic organochlorine pesticides and polychlorinated biphenyls and assessment of their xenoestrogenicity in the PA-MAMI mother-child cohort.

BACKGROUND: Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCB), they have contributed to the exposure of women to persistent organic pollutants (POPs). These compounds can cross the placental barrier and interfere with the hormonal system of newborns. AIM: To determine concentrations of OCPs and PCBs and their xenoestrogenic activity in placentas of women from the PA-MAMI cohort of Panama. METHODS: Thirty-nine placenta samples from women in the Azuero peninsula (Panama) were analyzed. Five OCPs [p-p'-dichlorodiphenyldichloroethylene (p-p'-DDE), beta-hexachlorohexane (ß-HCH), γ-hexachlorohexane (lindane), hexachlorobenzene (HCB) and mirex] and three PCB congeners (PCB-138, PCB-153 and PCB-180) were quantified in placenta extracts. The xenoestrogenic activity of extracts was assessed with the E-Screen bioassay to estimate the total effective xenoestrogen burden (TEXB). RESULTS: All placental samples were positive for at least three POP residues and >70% for at least six. The frequencies of quantified OCPs ranged from 100% for p,p'-DDE and HCB to 30.8% for ß-HCH. The highest median concentration was for lindane (380.0 pg/g placenta), followed by p,p'-DDE (280.0 pg/g placenta), and HCB (90.0 pg/g placenta). Exposure to p,p'-DDE was associated with greater meat consumption, suggesting that animal fat is a major source of exposure to DDT metabolites. The frequency of detected PCBs ranged between 70 and 90%; the highest median concentration was for PCB 138 (17.0 pg/g placenta), followed by PCB 153 (16.0 pg/g placenta). All placentas were positive in the estrogenicity bioassay with a median TEXB-α of 0.91 pM Eeq/g of placenta. Exposure to lindane was positively associated with the xenoestrogenicity of TEXB- α, whereas this association was negative in the case of exposure to PCB 153. CONCLUSIONS: To our best knowledge, this study contributes the first evidence on the presence of POPs and xenoestrogenic burden in placentas from Latin-American women. Given concerns about the consequences of prenatal exposure to these compounds on children's health, preventive measures are highly recommended to eliminate or minimize the risk of OCP exposure during pregnancy.

Assessment of legacy and alternative halogenated organic pollutants in outdoor dust and soil from e-waste sites in Nigeria: Concentrations, patterns, and implications for human exposure.

E-waste is often processed informally, particularly in developing countries, resulting in the release of harmful chemicals into the environment. This study investigated the co-occurrence of selected persistent organic pollutants (POPs), including legacy and alternative halogenated flame retardants (10 polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), syn and anti-dechlorane plus (DP)), 32 polychlorinated biphenyls (PCBs) and 12 organochlorine pesticides (OCPs), in 20 outdoor dust and 49 soil samples from 7 e-waste sites in Nigeria. This study provides the first report on alternative flame retardants (DBDPE and DP) in Nigeria. The total concentration range of the selected classes of compounds was in the order: ∑10PBDEs (44-12300 ng/g) > DBDPE (4.9-3032 ng/g) > ∑2DP (0.7-278 ng/g) > ∑32PCBs (4.9-148 ng/g) > ∑12OCPs (1.9-25 ng/g) for dust, and DBDPE (4.9-9647 ng/g) > ∑10PBDEs (90.3-7548 ng/g) > ∑32PCBs (6.1-5025 ng/g) > ∑12OCPs (1.9-250 ng/g) > ∑2DP (2.1-142 ng/g) for soil. PBDEs were the major contributors to POP pollution at e-waste dismantling sites, while PCBs were the most significant contributors at e-waste dumpsites. DBDPE was found to be significantly associated with pollution at both e-waste dismantling and dumpsites. Estimated daily intake (EDI) via dust and soil ingestion and dermal adsorption routes ranged from 1.3 to 2.8 ng/kg bw/day and 0.2-2.9 ng/kg bw/day, respectively. In the worst-case scenario, EDI ranged from 2.9 to 10 ng/kg bw/day and 0.8-5.8 ng/kg bw/day for dust and soil, respectively. The obtained intake levels posed no non-carcinogenic risk, but could increase the incidence of cancer at some of the studied e-waste sites, with values exceeding the USEPA cancer risk lower limit (1.0 × 10-6). Overall, our results suggest that e-waste sites act as emission point sources of POPs.

Short- and medium-chain chlorinated paraffins in sediment from the Haihe River Basin: Sources, distributions, and ecological risk assessment.

Chlorinated paraffins (CPs) can accumulate in sediment and pose risks to ecological systems and human health. The Haihe River Basin is one of the seven main river basins in China and is mainly in the Beijing-Tianjin-Hebei region, which is densely populated and very urbanized. There is therefore a high probability of CP pollution in the Haihe River Basin. However, CP pollution and the environmental risks posed by CPs in the Haihe River are not well understood. In this study, the concentrations of short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) in sediment from six rivers in the Haihe River Basin system were determined using two-dimensional gas chromatography electron-capture negative ionization mass spectrometry. The total SCCP and MCCP concentrations in the sediment samples ranged from 131.83 to 1767.71 and from 89.72 to 1442.82 ng/g dry weight, respectively. The total organic carbon content did not significantly correlate with the CP concentrations. The dominant SCCP congener groups were C10Cl6-7 and the dominant MCCP congener groups were C14Cl7-8. Significant relationships (R = 0.700, p < 0.05) were found between the SCCP and MCCP concentrations, indicating that SCCPs and MCCPs may have similar sources. Hierarchical cluster analysis and principal component analysis indicated that sediment in the study area was contaminated with CPs through the use of the CP-42 and CP-52 commercial products in industrial processes and human activities. The ecological risks posed by CPs were assessed and SCCPs were found to pose high risks in the Yongding New River but moderate risks in the other rivers. MCCPs were found to pose minimal risks to the aquatic environment at most of the sampling points.

Occurrence, distribution, and risk assessment of pesticides in surface water and sediment in Jiangsu Province, China.

The occurrence and distribution of 157 pesticides were investigated in surface water and sediment in Jiangsu Province, China. Gas chromatography-mass spectrometry was used to analyze and quantify these pesticides, and the risk quotient method was used to evaluate their respective environmental risk. The results showed that 91 pesticides were detected in surface water. The organophosphates (OPPs), fungicides, and amide herbicides were predominant. The total concentration in surface water ranged from 63.7 to 22,463 ng/L, 3.90 to 7262 ng/L, and ND to 34,120 ng/L, respectively. The mean concentration was 3479 ng/L, 1644 ng/L, and 1878 ng/L, respectively. The concentration range of detected pesticides in the Yangtze River Basin was generally lower than that in the Huai River Basin. In sediment samples, a total of 63 pesticides were detected. OPPs and amide herbicides were also ranked highest; the total concentration in sediment samples ranged from 2951 to 47,739 ng/g and 106 to 12,996 ng/g, respectively. And the mean concentrations was 6971 ng/g and 5130 ng/g, respectively. Suqian City had the highest concentration for OPPs and amide herbicides in the Huai River Basin, followed by Huai'an City, while Nanjing City and Yangzhou City ranked highest in the Yangtze River Basin. The spatial distribution of pesticides in Jiangsu Province indicated a concentration significantly higher in the western and northern regions than in the eastern and southern regions, and a concentration generally higher in lakes than in rivers. The risk assessment results showed that OPPs, fungicides, amide herbicides, organochlorines, and triazine herbicides in most surface water samples posed a high risk and had regional pollution characteristics. In sediment samples, organochlorines, carbamates, other herbicides, and other insecticides posed a high risk in northern Jiangsu Province, whereas OPPs, amide herbicides, and triazine herbicides posed high risks everywhere in Jiangsu Province.

First report on the exposure and health risk assessment of organochlorine pesticide residues in Caulerpa racemosa, and their potential impact on household culinary processes.

Seaweeds are widely consumed as natural seafood in various Asian countries. Chemical contaminants, such as pesticide residues (PRs), can contaminate it due to its high bio-accumulation nature. Limited research exists on the presence of PRs in edible seaweeds, their decrease in levels during cooking processes, and the evaluation of hazard indices and associated health risks to humans. This study investigated the effects of different cooking methods on the levels of organochlorine pesticides in Caulerpa racemosa seaweed. It also assessed the potential health risks associated with consuming seaweed by estimating daily intake, hazard quotient, and hazard index. The PRs were reduced after different cooking methods. The impact of thermal cooking on PRs in C. racemosa was found to be notably beneficial. The PRs decreased following MWC, boiling, and steam cooking. Several PRs were analyzed, and endrin, DDT, endosulfan, and cypermethrin were found to be the most prevalent. The HQ and HI values for raw and cooked seaweeds were found to be below one, suggesting that the PRs in C. racemosa pose no risk to consumers of seaweed. In summary, thermal cooking proves to be an efficient method for minimizing PRs, while the cooking of seaweeds ensures a high level of safety during consumption.

Increasing confidence in new approach methodologies for inhalation risk assessment with multiple end point assays using 5-day repeated exposure to 1,3-dichloropropene.

New Approach Methodologies (NAMs) are being widely used to reduce, refine, and replace, animal use in studying toxicology. For respiratory toxicology, this includes both in silico and in vitro alternatives to replace traditional in vivo inhalation studies. 1,3-Dichloropropene (1,3-DCP) is a volatile organic compound that is widely used in agriculture as a pre-planting fumigant. Short-term exposure of humans to 1,3-DCP can result in mucous membrane irritation, chest pain, headache, and dizziness. In our previous work, we exposed differentiated cells representing different parts of the respiratory epithelium to 1,3-DCP vapor, measured cytotoxicity, and did In Vitro to In Vivo Extrapolation (IVIVE). We have extended our previous study with 1,3-DCP vapors by conducting transcriptomics on acutely exposed nasal cultures and have implemented a separate 5-day repeated exposure with multiple endpoints to gain further molecular insight into our model. MucilAir™ Nasal cell culture models, representing the nasal epithelium, were exposed to six sub-cytotoxic concentrations of 1,3-DCP vapor at the air-liquid interface, and the nasal cultures were analyzed by different methodologies, including histology, transcriptomics, and glutathione (GSH) -depletion assays. We observed the dose-dependent effect of 1,3-DCP in terms of differential gene expression, change in cellular morphology from pseudostratified columnar epithelium to squamous epithelium, and depletion of GSH in MucilAir™ nasal cultures. The MucilAir™ nasal cultures were also exposed to 3 concentrations of 1,3-DCP using repeated exposure 4 h per day for 5 days and the histological analyses indicated changes in cellular morphology and a decrease in ciliated bodies and an increase in apoptotic bodies, with increasing concentrations of 1,3-DCP. Altogether, our results suggest that sub-cytotoxic exposures to 1,3-DCP lead to several molecular and cellular perturbations, providing significant insight into the mode-of-action (MoA) of 1,3-DCP using an innovative NAM model.