Polychlorinated Biphenyls Concentrations Research Articles

The Association between Serum Polychlorinated Biphenyls and Incident Cardiovascular Disease among Type 2 Diabetes

Abstract Background Polychlorinated biphenyls (PCBs) were associated with cardiovascular disease (CVD) in the general population. However, it is unclear whether PCBs exposure increases the additional risk of CVD among type 2 diabetes (T2D) cases. This study aims to investigate the associations between serum concentrations of PCBs and incident CVD among T2D cases. Methods The study population was derived from Dongfeng-Tongji cohort in 2008 and followed up until December 31, 2018, with a total of 2,806 participants with type 2 diabetes included and 1180 of them developed CVD during the follow-up. Cox proportional hazard regression models and quantile g-computation method were conducted for the associations of serum PCB levels with incident CVD risk. Results Compared with the first quartile, the risk of incident CVD was increased by 25%, 30%, and 28% in the fourth quartile of serum concentrations of PCB28, PCB52, and PCB101, respectively. Similar results were obtained for lower-chlorinated PCBs (PCB28 + PCB52 + PCB101) with HR (95% CI) of 1.257 (1.063, 1.486), and 1.346 (1.139, 1.589) in the third and fourth quartiles, respectively (P trend = 0.001). Quantile g-computation indicated that mixed exposure to PCBs increased the risk of CVD and the top three weights of PCB congeners were PCB101, PCB52, and PCB28. Conclusions Serum PCB independently increased the risk of incident CVD among T2D cases, in which lower-chlorinated PCBs played a dominant role.

Revisiting polychlorinated biphenyls enriching in human and disrupting of thyroid hormone receptor β1

Polychlorinated biphenyls (PCBs) are persistent organic pollutants renowned for their bioaccumation and toxicity. Although PCBs production and use were banned worldwide decades ago, PCBs still pose a health risk due to their environmental persistence and unintentional production. In this report, PCB concentrations and temporal trends in serum from residents of urban areas in eastern China is investigated. The endocrine-disrupting potentials of PCBs are also investigated, particularly effects on thyroid hormone receptors. Through analysis of five years of data, results indicated that dioxin-like PCBs and congener PCB209 concentrations maintained low and had no marked temporal trends, but that the indicator PCBs and particularly PCB52, PCB153, and PCB180 concentrations increased. Furthermore, to evaluate binding of PCBs to the thyroid hormone receptor TRβ1, molecular docking simulations are performed. It is found that the PCBs of PCB28, PCB52, and PCB153 can interfere with triiodothyronine binding to TRβ1, which are comparable to the effects of the polybrominated biphenyl BB-153, a known thyroid function disruptor. What's more, the PCB180 binds to TRβ1 more strongly than that of BB-153. Our results indicated that a continuously monitoring of human exposures to PCB28, PCB52, PCB153, PCB180, and a detailed assessment of thyroid function interference is necessary.

Target, suspect, and non-target analysis of halogenated organic pollutants in spotted seals (Phoca largha) from Peter the Great Bay, East Sea/Sea of Japan

Target, suspect, and non-target analyses were conducted to investigate the accumulation status of halogenated organic pollutants (HOPs) in spotted seals (Phoca largha Pallas, 1811) from Peter the Great Bay, East Sea/Sea of Japan. Despite long-standing regulations, polychlorinated biphenyls (PCBs) and organochlorine pesticides were highly accumulated, likely due to placental and lactational transfer. Hexabromocyclododecanes were the predominant brominated flame retardants, with their levels increasing with age. Suspect and non-target analyses identified 35 non-target PCBs not routinely monitored, suggesting conventional methods may underestimate PCB concentrations. Regression analysis showed significant correlations between the concentrations of major PCBs (CBs 138 and 153) and the sum of target and non-target PCBs. The study found that 95 % of the seals exceeded threshold levels for PCBs, posing potential health risks. These findings highlight the need for integrated monitoring, combining target and non-target analyses, to better assess and manage the risks of HOPs to marine mammals.

Inter- and intraspecific blood-related biomarkers and chemical exposure in confined and free-living sea turtles.

The relevance of recovery centers and head-starting programs for rescue, rehabilitation, rearing, and conservation of sea turtles is recognized worldwide. In addition, these centers contribute to generating biochemical and physiological data needed to identify health markers and provide baseline values. Because of the marine ecosystems' deterioration, biomarker identification is a global priority for sea turtle conservation; nevertheless, information on specific endpoints, such as neurotoxicity and mutagenesis, is still limited in sea turtles. This study aimed to contrast a set of non-invasive blood biomarkers with ecotoxicological and clinical applications in confined green sea turtles (Chelonia mydas) compared with free-living ones from the Mexican Caribbean. Additionally, interspecific (green, hawksbill (Eretmochelys imbricata), loggerhead (Caretta caretta) turtles) differences were also evaluated. Plasmatic organochlorine pesticides (OCs) and polychlorinated biphenyl (PCBs) were also determined. The concentration ranges of uric acid, total proteins, lipids (cholesterol and triglycerides), and thyroxine of both confined and free-living green turtles fell outside the reference intervals for the species. Additionally, confined green turtles had the highest number of erythrocytic nuclear abnormalities (ENA) and elevated levels of hemoglobin, lipid peroxidation, and activity of glutathione S-transferase, glutathione peroxidase, and carboxylesterase (CE). Contrasts among confined species identified hawksbill turtles with the lowest glutathione reductase activity, green turtles with the lowest ENA frequency and CE activity, and loggerhead turtles with the highest plasmatic concentrations of PCBs and OCs. The information here provided can be used as information in health monitoring programs and for conservation and management policies at regional, national, and international level.

Modelling the association between the El Niño Southern Oscillation and levels of legacy pollutants in Alaskan seabird eggs from 1999 to 2010

BackgroundThe circumpolar north has long been a sink for legacy persistent organic pollutants (POPs). Under a warmer climate, these contaminants are predicted to remobilize within environmental media where they are subject to climate processes, underscoring the need to examine the effects of large-scale climate oscillations on the fate of legacy POPs. MethodsWe apply piecewise log-linear spline regression models with non-parametric bootstrapping to measure the association between the El Niño Southern Oscillation (ENSO), a measure of Pacific sea surface temperature variability, and levels of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) measured in common murre (Uria aalge) and thick-billed murre (Uria lomvia) eggs collected from the Gulf of Alaska and Bering Sea between 1999 and 2010. ResultsIn thick-billed murres, average PCB concentrations increased 143 % per unit increase in ONI during the warm phase of the ENSO, with a meta-regression pooled estimate of 0.887 (95 % CI: 0.674, 1.099). Similarly, average PBDE concentrations increased 562 % per unit increase in ONI during the warm phase, with a pooled estimate of 1.890 (95 % CI: 0.647, 3.133). During the cool phase, average PCB concentrations decreased 59 % per unit increase in ONI, with a pooled estimate of −0.892 (95 % CI: −1.400, −0.384). In common murres, average PCB concentrations decreased 51.4 % per unit increase in ONI during the warm phase, with a meta-regression pooled estimate of −0.722 (95 % CI: −0.894, −0.549), and increased 39.5 % per unit increase in ONI during the cool phase, with a pooled estimate of 0.333 (95 % CI: 0.185, 0.481). Average PBDE concentrations decreased 79.2 % per unit increase in ONI during the warm phase, with a pooled estimate of −1.572 (95 % CI: −2.357, −0.787). ConclusionOur results indicate associations between the ENSO and PCB and PBDE loads in Alaskan murre eggs, suggesting the ENSO may be an important factor in the fate of legacy POPs within Alaskan marine food webs. To our knowledge, this is the first paper to link the ENSO and levels of legacy POPs in Alaska's environment and may be relevant to health and food security in this region.

Assessing the Interrelationship Between Microplastics and Polychlorinated Biphenyls Contamination in Chinese Mangrove Sediment

Mangrove ecosystems, critical intertidal zones at the land–ocean interface, are increasingly recognized for their role in microplastic (MP) pollution dynamics. Despite extensive research on the interaction of MPs with various chemical contaminants, the specific contamination levels of polychlorinated biphenyls (PCBs) associated with MPs in mangroves remain poorly understood. In this study, we quantified the concentrations of PCBs on MPs extracted from representative mangrove sediment samples across China, revealing values ranging from 9.80 to 13.91 ng/g. In contrast, PCB concentrations in sediment samples were found to vary between 25.67 and 69.85 ng/g. Our findings indicate a consistent level of PCB contamination on MPs across different sites, although these levels were marginally elevated compared to those in the surrounding sediments. Notably, Penta-PCBs were detected with the highest frequency across all samples analyzed. This study provides crucial insights into the occurrence and distribution of PCBs on MPs within the mangrove ecosystem, highlighting their significance in environmental contamination assessments.

Ocean as source or sink for legacy persistent organic pollutants.

With the phase-out of legacy persistent organic pollutants (POPs), the ocean's role is evolving, potentially acting as both a reservoir and a source. This study investigates the air-sea fluxes of the first banned POPs, such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), using literature from Web of Science up to 2023. OCP and PCB concentrations in air and seawater show significant spatiotemporal variability. In air, α-HCH and p,p'-DDE dominate, with concentrations decreasing over time and varying with latitude. In seawater, α-HCH and p,p'-DDTs show higher levels in the Northern Hemisphere and significant temporal decreases. PCB concentrations differ notably between low- and high-chlorinated compounds, with distinct spatial patterns. HCHs exhibit distinct flux patterns, with volatilization in equatorial regions and deposition in higher latitudes. DDTs mainly show deposition trends, except in Southeast Asia where recent increases in volatilization are observed. PCBs generally demonstrate deposition, with regional and seasonal variations. Time significantly impacts fluxes due to changes in human activity and regulations. High-chlorine PCBs are more affected by distance from the sea surface, while temperature increases POPs volatilization.

Polychlorinated dibenzo-dioxin/furan and polychlorinated biphenyl concentrations in the human milk of individuals living near municipal waste incinerators in the UK: Findings from the Breast milk, Environment, Early-life, and development (BEED) human biomonitoring study.

The objective of this study is to report recent PCDD/F and PCB human milk concentrations in the United Kingdom (UK) and relate these to two proxies for exposure to municipal waste incinerator (MWI) emissions. As part of the Breast milk, Environment, Early-life, and Development (BEED) study, primiparous individuals were recruited from within 20km of English MWIs between 2013 and 2015 and asked to provide human milk samples. The samples were analysed for quantitative concentrations of 17 PCDD/F and 12 PCB congeners. Linear regression models were used to investigate the association between two proxy measurements for exposure to MWI emissions: (i) log average modelled daily ground-level PM10 from MWIs (modelled PM10) and (ii) residential proximity to nearest MWI and the toxic equivalents (TEQs), ∑TEQ2005-PCDD, ∑TEQ2005-PCB and ∑TEQ2005-PCDD/F+PCB. Samples from 194 participants were analysed for PCDD/Fs and 150 for PCBs. Overall ∑TEQ2005-PCDD/F+PCBs ranged from 1.76 to 25.1pg/g lipid with a geometric mean of 5.81 (Geometric standard deviation: 1.64). A doubling in modelled PM10 was significantly associated with an average increase of 9.71% (95% CI: 2.91%-16.5%) in ∑TEQ2005-PCDD/Fs+PCB, 9.14% (95% CI: 1.79%-16.5%) in ∑TEQ2005-PCDD/Fs and 9.02% (CI:1.57%-16.5%) in ∑TEQ2005-PCBs. MWI proximity was not associated with an increase of ∑TEQ2005-PCDD/Fs, ∑TEQ2005-PCBs, or ∑TEQ2005-PCDD/Fs+PCBs. The results from this study suggest that MWI emissions may make a small contribution to the body burden of toxic PCDD/F and PCB mixtures. Enhanced environmental monitoring and human biomonitoring of PCDD/Fs and PCBs near MWIs would be needed to investigate this further.

Health risk assessment of phthalate esters and polychlorinated biphenyls from marine plastic pollution in coastal areas of Lagos, Nigeria.

Marine plastic pollution, a major public health issue worldwide, releases toxic persistent organic pollutants (POPs) causing endocrine disruption, cancers, and other adverse effects. However, research on these compounds in the Nigerian marine environment is limited. Using a cross-sectional design and incorporating a laboratory component, this study aimed to assess the health risks associated with marine plastic pollution at Orimedu, Idado, and Eleko along the coastline of Lagos, Nigeria. A total of three coastal water and sediment composite samples were collected over 10m from the shore into the ocean at each study area. The samples were analyzed for concentration levels of six phthalate esters (PEs) and 23 polychlorinated biphenyls (PCBs) using gas chromatography/mass spectrometry (GC/MS) and gas chromatography-electron capture detector (GC-ECD) after preparation. Health risk assessment was also computed using risk assessment models developed by the United States Environmental Protection Agency (USEPA). Results obtained were compared to the World Health Organization's (WHO) standards for cancer risk (1.0 × 10-5) and non-cancer risk (≤ 1.0). Eleko had the highest concentrations of both PEs (24.89 ± 0.01mg/L of DIOP) and PCBs (0.06 ± 0.01 of PCB 206-2,2',3,3',4,4'5,5',6-nonachlorobiphenyl) in the water samples, while in the sediment samples, Idado had the highest PE (69.00 ± 0.05 of DIOP) and Orimedu was found with the highest PCB (0.09 ± 0.03 of PCB 180-2,2',3,4,4',5,5'-heptachlorobiphenyl). Most of the PEs and PCBs were above the limits set by the WHO. Further studies are needed to address the health risk assessment of PEs and PCBs, especially in children and adults, in the coastline communities of Lagos.

The human health risks and corresponding body thresholds of OCPs and PCBs in the Tibetan Plateau

Although organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been banned or restricted for years, they remain significant contaminants posing health risks in some places where are favorable for their enrichment, such as areas with high latitude or altitudes. However, the elucidation of environmental risks and the establishment of a clear relationship between these risks and human health are areas that remain significantly underdeveloped. Literatures on the concentrations of OCPs and PCBs in soil of the Tibetan Plateau were reviewed to calculate local health risk indexes and create risk maps. A food chain model (ACC-Human) was applied to predict human body concentrations of these chemicals. Higher risk areas are located in the southeastern Tibetan Plateau, suggesting influences from potential emissions in adjacent regions and long-range transport. Based on the concentration-risk relationships, the most toxic chemicals identified were PCBs, with a body concentration threshold as low as 13 ng/g lipid. Given the ongoing emissions from industrial production or historical legacy, it is hightime to lay a particular focus on PCBs in mountainous areas like the Tibetan Plateau.

Comprehensive evaluation of skin exposure to PBDEs and PCBs in diverse South China populations via dermal wipe sampling.

This study analyzed skin wipe samples from the forehead, palm, forearm, and lower leg of 120 volunteers across different age groups-preschoolers, thresholders, middle-aged, and elderly-with each group comprising 30 individuals with a balanced sex ratio from a city in South China. The research aimed to assess the occurrence, concentration, and associated health risks of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) adsorbed onto human skin from environmental sources. We identified 13 PBDE congeners and 10 PCB congeners across all samples, with average detection frequencies of 48% for PBDEs and 16% for PCBs, with concentrations ranging from non-detectable (ND) to 4200 and ND to 2300ng/m2, respectively. Skin concentrations of both PBDEs and PCBs decreased in the order of face > hand > arm > shank (ANOVA, P < 0.001), suggesting higher exposure to uncovered skin areas than to those covered by clothing, regardless of age or sex. The daily average dose of dermal (DADderm) and oral (DADoral) for PBDEs spanned from 7.0 × 10-4-0.19ng/kg/d and ND-15 ng/kg/d, respectively, whereas the PCB exposure doses ranged from ND-7.8ng/kg/d (DADderm) and ND-2.0ng/kg/d (DADoral), respectively. Preschool children displayed notably higher DADoral levels than the other groups (P < 0.0001), which was attributed to their more frequent hand-to-mouth activity. Preschool boys exhibiting a higher DADderm (P < 0.05) and both preschool boys and university women showing elevated DADoral levels (P < 0.01 and P < 0.05, respectively). Health risk assessments concluded that the carcinogenic risks from BDE209 and PCBs were within acceptable limits (10-4) for all sampled populations.

Source identification and human health risk to polychlorinated biphenyls in public parks and playground surface soils, southern zone of Ghana.

Polychlorinated biphenyls (PCBs) constitute a typical example of persistent organic pollutants (POPs) that have been detected globally in most environmental media. Soil serves as a critical reservoir for PCBs. This research is aimed at evaluating the potential exposure and associated health risks posed by soil-laden PCBs to humans during outdoor activities on public playgrounds and parks within the southern zone of Ghana where limited studies have been undertaken. Surface soils collected from 56 sites were processed and analyzed for seven indicator PCBs in soil particle sizes less than 63µm. A multi-residual analytical approach for the simultaneous analysis of PCBs and polycyclic aromatic hydrocarbons (PAHs) via gas chromatography tandem mass spectrometry was utilized. The results indicated that the concentration of PCBs ranged from 0.26 to 24.00µg/kg with an average total concentration of 1.86 ± 3.23µg/kg which is below the environment guideline threshold of 1.3mg/kg stipulated by the Canadian Council of Ministers for residential playgrounds/parkland soils. Multivariate analysis showed that the sources of the PCBs could be attributed predominantly to historical release, atmospheric transfer, and deposition. The excess lifetime cancer risks posed to children and adults are less than 10-6 thereby implying the existence of low carcinogenic health risk to the human populace within the southern zone of Ghana. Thus, the conduct of outdoor activities at the public playgrounds/parks within these highly populated areas poses no significant risk to human health.

Pathological Changes and CYP1A1 Expression as Biomarkers of Pollution in Sarpa Salpa and Diplodus Sargus.

In a marine ecosystem, the most sensitive organisms to environmental changes, mainly to anthropic pressures, are fishes and invertebrates. Therefore, they are considered the ideal targets to indirectly evaluate the health of an entire ecosystem. Teleost fishes, particularly those that occupy the highest trophic levels, can accumulate toxic substances through their diet. In this study, we used two fish species with sedentary behavior and trophic habits, Diplodus sargus and Sarpa salpa, caught in two areas at different anthropic pressures divided into the Gulf of Naples (Na) and the Gulf of Salerno (Sa). This study aimed to correlate the pathological alterations in target organs in both species with known concentrations of polychlorinated biphenyls (PCBs) and heavy metals (lead and cadmium) to the expression of CYP1A1. Histological examination took into consideration circulatory disorders, increase in melanomacrophages (MMs) number, inflammation in kidney and hepatopancreas and gonadal stage maturation. Next, the pathological and morphological changes found were compared to immunohistochemical expression of CYP1A1 in the same samples. Chemical analysis of PCBs, based on 28, 52, 101, 138, 153, and 180 congeners, and heavy metals, were performed on hepatopancreas and muscle samples. Higher median values of PCBs concentration were detected in both species in the Salerno area (8.1 ng/g in Diplodus sargus muscles and 51.1 ng/g in Sarpa salpa hepatopancreas, respectively), although the values were consistently below the legal limits. No critical values were found for lead and cadmium. Therefore, we hypothesized that CYP1A1 and pathological alterations were more expressed in fish from Salerno area. The pathological changes showed a statistically significant difference in inflammation of the kidneys (p < 0.0001) between S. salpa of both Gulfs. In addition, we found a statistically significant difference in the assessment of the increase in MMs/MMCs (p = 0.0384) and circulation disorders (p = 0.0325) of hepatopancreas in D. sargus of both Gulfs. As not all the variables considered showed statistical significance, the analysis of the results does not fully support the correlation between the highest levels of contaminants found in the Salerno area and the expression of CYP1A1. Our data could be a starting point for future studies to better correlate the role of CYP1A1 to pollutants, considering this is the first study involving two of the most common species in the Mediterranean Sea. Thus, future studies could include other species to improve and increase records.

Metabolic activation of WHO-congeners PCB28, 52, and 101 by human CYP2A6: evidence from in vitro and in vivo experiments.

Despite extensive research on the metabolism of polychlorinated biphenyls (PCBs), knowledge gaps persist regarding their isoform-specific biotransformation pathways. This study aimed to elucidate the role of different cytochrome P450 enzymes in PCB metabolism, focusing on WHO-congeners 2,4,4'-trichlorobiphenyl (PCB28), 2,2',5,5'-tetrachlorobiphenyl (PCB52), and 2,2',4,5,5'-pentachlorobiphenyl (PCB101). Utilizing engineered HEK293 cell lines, we investigated the in vitro metabolism of these PCBs by CYP1A2, CYP2C8, CYP2C9, CYP3A4, CYP2A6, and CYP2E1, revealing robust production of hydroxylated metabolites. Our results show that CYP2A6 plays a major role in the metabolism of these congeners responsible for predominant formation of para-position hydroxylated metabolites, with concentrations reaching up to 1.61µg/L (5,89nM) for PCB28, 316.98µg/L (1,03µM) for PCB52, and 151.1µg/L (441nM) for PCB101 from a 20µM parent PCB concentration. Moreover, concentration-dependent cytotoxic and cytostatic effects induced by reactive intermediates of the PCB hydroxylation pathway were observed in HEK293CYP2A6 cells, for all three congeners tested. CYP2A6 was specifically capable of activating PCBs 28 and 101 to genotoxic metabolites which produced genetic defects which were propagated to subsequent generations, potentially contributing to carcinogenesis. In a clinical study examining CYP2A6 enzyme activity in formerly exposed individuals with elevated internal PCB levels, a participant with increased enzyme activity showed a direct association between the phenotypic activity of CYP2A6 and the metabolism of PCB28, confirming the role of CYP2A6 in the in vivo metabolism of PCB28 also in humans. These results altogether reinforce the concept that CYP2A6 plays a pivotal role in PCB congener metabolism and suggest its significance in human health, particularly in the metabolism of lower chlorinated, volatile PCB congeners.

Factors affecting the polychlorinated biphenyl signatures in serum of adults living in a highly polluted area in eastern Slovakia.

Over the years eastern Slovakia has been subject to consistent monitoring of high levels of polychlorinated biphenyls (PCBs) in both the environment and human populations attributed to the former production of PCBs at the Chemko Strážske plant. We aimed to investigate the extent to which dietary habits and residential location could affect the concentrations of PCBs in the blood serum samples of subjects. We enrolled 602 adult subjects from eastern Slovakia with an average age of 45.14 (±8.49) years. To determine the concentrations of 21 PCB congeners, we used solid phase extraction along with gas chromatography coupled with high-resolution mass spectrometry. Based on questionnaire data, the assessment of dietary habits and residential location was performed using score calculations and creating a map. Through principal component analysis, the 20 PCB congeners were classified into three groups: PC1, comprising highly chlorinated PCBs, and PC2 and PC3, consisting primarily of low chlorinated PCBs. Stepwise multivariate regression revealed positive and negative associations between PCB congeners represented by PC1-3 and scores related to the residential location and scores related to food consumption, respectively. We confirmed that levels of PCBs represented by PC1-3 increased with age. The geographical proximity to pollution sources proved to be a key contributing factor to the observed PCB levels in individuals residing in eastern Slovakia.

Determination of polychlorinated biphenyls (PCBS) using gas chromatography electron capture detector in dust from schools in Okitipupa, Ondo State, Nigeria

The presence of polychlorinated biphenyls (PCBs) in dust, and subsequent exposure to humans via unintentional ingestion, inhalation, or skin contact, has serious health repercussions due to their toxicity profiles. There is a lack of knowledge concerning the concentration of PCBs in the dust/atmosphere. The quantities of seven (7) polychlorinated biphenyls (PCBs) in outdoor dust were measured at five different locations across southern Ondo State, Nigeria. The study's purpose was to provide data on the distribution of polychlorinated biphenyls (PCBs) in air dusts and to assess the influence of metrological parameters on PCB dust concentration. The PCB content was evaluated with a gas chromatography-electron capture detector (GC-ECD). PCB values varied from 1.51–32.52 µg/kg. Six (6) PCBs were below the detection limit in five separate sites. The total content of polychlorinated biphenyls (PCBs) in air dust displayed a negative (-0.614) and strong connection with wind speed, a positive (0.023) and bad correlation with temperature, and a positive (0.485) but poor association with relative humidity. In conclusion, the level of atmospheric PCBS has no significant effect on meteorological parameters. The EPA's health-based screening standard for total PCBs is 0.22 μg g¹, which aim to prevent deleterious effects from long-term exposure.

Health risks and sources of PCDD/Fs and PCBs residue in cultured crabs

The Chinese mitten crab (Eriocheir sinensis) holds significant importance as a popular aquaculture food source; however, there are concerns about its potential contamination with polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) from both food and aquatic environment. To assess the associated health risks and identify potential sources of contamination in crabs, a comprehensive investigation was conducted, including a total of 70 samples from the crab food web. The results demonstrated that crabs predominantly exhibited elevated concentrations of PCBs and dl-PCBs, with mean concentrations of 12 207 ± 11 962 pg g-1 and 554 ± 203 pg g-1, respectively, while PCDD/Fs concentrations were comparatively lower at 20 ± 17 pg g-1. The accumulation of PCBs in crabs significantly surpassed that of PCDD/Fs. The material balance of PCDD/Fs and PCBs in the crab food web was estimated, indicating that sediments and feeds likely constitute the two primary sources of PCDD/Fs and PCBs in crabs. The monthly intake of PCDD/Fs and PCBs through crab consumption accounted for 30% of the dietary intake, which was well below the provisional tolerable monthly intake (PTMI) limit. The weekly intake of PCDD/Fs and PCBs for adults consuming one crab (100 g) does not pose health risks and the recommended weekly intake of white crabmeat and brown crabmeat is 443 g and 21 g, respectively.

Spatial patterns, source apportionment, and risk assessment of polychlorinated biphenyls (PCBs) in the surface sediments of eastern China lakes along a latitudinal gradient: Insights guided by full-congener analysis

Understanding the occurrence, sources, and ecological risks of polychlorinated biphenyls (PCBs), which are universal persistent organic pollutants, is critical for improving the sustainability and ecological safety of lake systems. Herein, to determine PCB contamination levels and formulate control strategies in lake sediments, 210 sediment samples were collected from 21 lakes along a latitudinal gradient (18–45°N, ∼3000 km) across eastern China and were analyzed for all 209 PCB congeners. The results showed that the total PCB concentration varied greatly from 0.26 to 163.82 ng/g dry weight and exhibited a latitudinal trend of central > north/south. Spatial variations were affected mainly by the organic carbon fraction and local population density. Most lakes had similar PCB profiles, with lower chlorinated PCBs dominating. Notably, non-Aroclor PCB 11 was the most abundant congener. Moreover, unintentionally produced PCBs (UP-PCBs) accounted for ∼31 % of all PCBs. These findings highlight that the significance of UP-PCBs has been overlooked in past studies and that full-congener analysis is necessary for future monitoring. According to the ecological risk assessment of PCBs, zero to moderate risk existed in lake sediments. Therefore, effective strategies are needed to mitigate the impact of PCBs (especially UP-PCBs) from multiple sources on lakes.

Atmospheric Transport of Semivolatile Organic Contaminants across an Urban-Alpine Boundary.

Current understanding of atmospheric transport of semivolatile organic contaminants (SVOCs) in alpine areas is limited due to complex meteorology and topography. Salt Lake City, Utah borders protected wilderness areas in the Wasatch Mountains, exhibiting a useful model system in which an urban source of SVOCs, including polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), is located directly adjacent to an alpine sink. Our objective was to investigate the impacts of topographical features on the transport and deposition of SVOCs across an urban-alpine boundary. To do so, we measured PAHs and PCBs in soils along a transect starting at the urban-mountain interface and extending into an alpine wilderness, crossing several prominent ridgelines. Concentrations of PAHs and PCBs in soils were heavily influenced by soil organic carbon content, air temperature, and proximity to the urban boundary. However, the role of source proximity was only revealed after normalizing concentrations in soil to organic carbon content and air temperature. Further, we present evidence of SVOC emission/deposition cycles driven by diurnal alpine winds that do not extend past topographical features. Our results illustrate the roles of multiple competing processes on SVOC transport in alpine systems and their importance at an urban-alpine boundary.

The Interplay of Persistent Organic Pollutants and Mediterranean Diet in Association With the Risk of Gestational Diabetes Mellitus.

Certain foods characterizing the alternate Mediterranean diet (aMED) are high in persistent organic pollutants (POPs), which are related to greater gestational diabetes mellitus (GDM) risk. We examined the associations of combined aMED and POP exposure with GDM. aMED score of 1,572 pregnant women was derived from food frequency questionnaires at early pregnancy within the U.S. Fetal Growth Study and plasma concentrations of 76 POPs, including organochlorine pesticides, polybrominated diphenyl ethers, polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances, were measured. Associations of combined aMED score and exposure to POPs with GDM risk were examined by multivariable logistic regression models. In 61 of 1,572 (3.88%) women with GDM, 25 of 53 included POPs had a detection rate >50%. Higher POP levels appeared to diminish potential beneficial associations of aMED score with GDM risk, with the lowest GDM risk observed among women with both high aMED score and low POP concentrations. Specifically, adjusted log-odds ratios of GDM risk comparing women with low PCB and high aMED score with those with low aMED score and high PCB concentrations was -0.74 (95% CI -1.41, -0.07). Inverse associations were also observed among women with low aMED score and high TransNo_chlor, PCB182_187, PCB196_203, PCB199, and PCB206. These associations were more pronounced among women with overweight or obesity. Pregnant women who consumed a healthy Mediterranean diet but had a low exposure to POP concentrations had the lowest GDM risk. Future endeavors to promote a healthy diet to prevent GDM may consider concurrent POP exposure.