Dioxin-like Polychlorinated Biphenyls Research Articles

Non-dioxin-like polychlorinated biphenyls (NDL-PCBs) dietary exposure is associated with an increased risk of type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Aims/hypothesisThe aim of the present study was to investigate the association between dietary exposures to dioxins, dioxin-like polychlorinated biphenyls (DL-PCBs) and non-dioxin-like polychlorinated biphenyls (NDL-PCBs) and the incidence of type 2 diabetes mellitus (T2DM) in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. MethodsThis prospective cohort study with a median 11.7 years of follow-up, included 318,416 individuals recruited in 21 centers in eight countries. Dietary intake of dioxins and PCBs was calculated by combining EPIC food consumption data with food contamination data from the European Food Safety Authority (EFSA). To identify incident cases of T2DM, a thorough review of various sources including self-reported information, linkage to primary and secondary care registers, drug registers, hospital admissions, and mortality data was conducted. Associations between dietary intake of dioxins and PCBs and T2DM were evaluated using multivariable Cox regressions. ResultsHigher T2DM risk was observed for higher estimated dietary intake of non-dioxin-like PCBs (NDL-PCBs; HR per 1 SD increment = 1.03 [95%CI 1.01;1.04], and HR (Q4 vs Q1) = 1.15 [1.08;1.22], P-trend < 0.001). The results were consistent in analyses stratified by gender, body mass index, country, median follow-up, or self-reported hypertension and hyperlipidemia, as well as when adjusting for fat intake. No consistent association was observed between dioxins+DL-PCBs intake and T2DM risk. Conclusion / interpretationResults obtained in this large European prospective study indicate a positive and linear association between dietary intake of NDL-PCBs and risk of T2DM. This association remained consistent across various stratified and sensitivity analyses. Further studies are warranted to better understand the biological mechanisms underlying this association.

Dietary exposure to metals/metalloids and persistent organic pollutants in Spanish preschool and primary school children

Diet is a primary source of pollutant exposure. Given children's vulnerability to their effects, this study assessed dietary intake of metals/metalloids and different persistent organic pollutants in children in Tarragona (Spain), compared it with the health-based guideline values (HBGV), and identified the main dietary sources. The analysis included 533 preschoolers and 443 primary school children from the EPINED and ECLIPSES studies. Dietary intake of cadmium (Cd), methylmercury (MeHg), lead (Pb), inorganic arsenic (inAs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), and non-dioxin-like polychlorinated biphenyls (NDL-PCBs) was estimated using validated food frequency questionnaires and a database from the Catalan Agency for Food Safety. Preschoolers and primary school children exceeded the relevant reference value for InAs and DL-PCBs. Only preschoolers exceeded the limit for MeHg and PCDD/Fs. Cd, Pb, and NDL-PCBs intakes did not exceed the limits in either age group. Salted cereals/potatoes were the main source of InAs; fish for MeHg and DL-PCBs; and milk/yogurt for PCDD/Fs, followed by white fish in preschoolers and fatty fish in primary school children. The findings highlight that dietary exposure to some pollutants poses a significant risk to these children, emphasizing the need for public health policies to reduce pollutants in their diets.

Release of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) from cigarette butts into the aquatic environment: Levels and ecotoxicity

Discarded cigarette waste may leach toxic elements and can contaminate different environments. In this study, the levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in cigarette butts (CBs) leachates were determined, and the release rate of these pollutants from three CBs types such as smoked CBs with and without tobacco (SCBs and SFs) and unsmoked filters (USFs) were examined. The mean concentration levels of PCBs compounds were <LOD-1.36, <LOD-1.02 and <LOD-0.86 μg/L in SCBs, SFs, and USFs leachates, respectively. The concentrations of OCPs in SCBs and SFs leachates were <LOD-0.14 and <LOD-0.10 μg/L, respectively. The toxic equivalent (TEQ) of the dioxin-like PCBs from the CBs leachate samples ranged from 2×10-6-1×10-4 ng/L. Notwithstanding the insignificant TEQ values in CBs leachates, continuous discharge and the toxicities of the PCBs in the aquatic environments could have harmfully impacts on the the water boddies and/or human health. Globally, considering all the littered CBs and their chemical contents, further efforts are needed to investigate address, and mitigate this type of contamination.

Dioxin concentrations and congener distribution in biomass ash from small to large scale biomass combustion plants.

Biomass plays a pivotal role in global energy production, with a significant share allocated for industrial heat and power generation. The combustion of biomass generates biomass ash, which is widely utilized as a fertiliser. However, concerns arise regarding the presence of dioxins in biomass ash, which may limit its continued use. Dioxins are toxic compounds listed under the Stockholm Convention due to their persistence and detrimental effects on human health and the environment. This study investigates the dioxin content in biomass ashes produced in various combustion plants with a capacity of 1-50MWth in Estonia, where biomass is widely used for heating and power production. The research encompassed samples from nine biomass combustion plants with varying technical parameters considering both bottom and fly ash. Dioxin concentrations were determined for 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), and 12 dioxin-like PCBs (PCBs). The results indicate that dioxin TEQ content in all samples was well below the European Union's (EU) POP Regulation limit of 5µg TEQ/kg, with most values being at least tenfold lower. However, some samples failed to meet the EU Fertilising Products Regulation's threshold of 20ng TEQ/kg. Notably, fly ash exhibited higher dioxin concentrations than bottom ash. While PCBs were in significant concentrations, PCDDs dominated the overall dioxin TEQ content. This study provides essential insights into the dioxin content in biomass ash and its correlation with current EU regulatory limits. It also highlights the complex distribution of dioxin congeners, particularly PCBs, within biomass ash, emphasizing the continued research's importance.

Occurrence, sources and risk assessment of 12 dioxin-like polychlorinated biphenyls (DL-PCBs) in sediments from the Soummam River protected area, Algeria: A potential threat to the Mediterranean Sea

The levels, the sources and the potential risks associated with twelve dioxin-like PCBs were investigated in the sediments of the Soummam River in northeastern Algeria. Total dl-PCBs concentrations ranged from 3.64 ng/g to 9.38 ng/g with PCB 118 and PCB 105 being the predominant congeners. Principal component analysis suggested that commercial mixtures and municipal waste incineration could be responsible for the presence of PCBs in the region. TEQ values ranged from 12.93 pg/g to 60.98 pg/g indicating adverse effects on aquatic organisms. Moreover, cancer risk assessed via Total Lifetime Cancer Risk (TLCR) suggested that for all the stations, the risk was low but not negligible. Additionally, the non-cancer risk was significant at half of the stations for children but negligible for adults at all the stations. Consequently, measures must be taken by local authorities to protect the environment and the human health.

Dioxins, PFOS, and 20 other Persistent Organic Pollutants in Eggs of Nine Wild Bird Species from the Vaal River, South Africa

The Vaal River catchment drains the largest and most populated industrial and mining region in Southern Africa. Heron, ibis, cormorant, egrets, and darter eggs, representing three habitats and four feeding guilds, were collected at four locations in 2009/10 to identify hotspots and hazards associated with persistent organic pollutants (POPs). The POPs included 21 organochlorine pesticides, five polybrominated diphenyl ether (PBDE) classes, 18 polychlorinated biphenyls (PCBs including six non-dioxin-like PCBs; NDL-PCB), and 12 dioxin-like PCBs (DL-PCBs), 17 polychlorinated dibenzo-p-dioxins and dibenzo-p-furans (PCDD/Fs), and perfluorooctane sulfonate (PFOS). Aquatic predators had higher PFOS and PCDD/F concentrations, while PCBs dominated in terrestrial eggs. Organochlorine pesticides, PBDEs, and PCBs were strongly associated with eggs from the industrial regions, while PCDD/F concentrations were evenly distributed. PCDD/F and PCB toxic equivalency quotient concentrations were low with no adverse effects expected. PFOS peaked at Bloemhof Dam with a maximum of 2300 ng/g wm in an African Darter egg, indicating an unexpected PFOS hotspot, the source of which is unknown. Despite order of differences in compound class concentrations, there was no association with egg size. To the best of our knowledge, this is the only study that analysed all 2010 POPs in bird eggs on a large geographic scale. This study highlighted the importance of multi-species studies sampling from multiple locations to assess the risk that POPs pose to avian populations as hotspots and species at risk may be missed by studies looking at one or few species.

Temporal variations in airborne PCDD/F and dl-PCB concentrations surrounding the dioxin-remediated areas in Da Nang, Vietnam, and health risk assessments.

The air pollution levels from polychlorodibenzo-p-dioxins/polychlorodibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) in three residential areas located north, west, and south of the Da Nang airport were determined by using passive air samplers containing polyurethane foam (PUF) discs with 3-month sampling intervals from 2017 to 2020. The total toxic equivalents (∑TEQs) of the PCDD/Fs and dl-PCBs, using WHO2005-TEFs, were highest north of the airport (134 to 10610fg WHO-TEQ/PUF day, with an average of 1108fg WHO-TEQ/PUF day). The ∑TEQs were lower west of the airport, between 159 and 381fg WHO-TEQ/PUF day and averaged 230fg WHO-TEQ/PUF day. The lowest ∑TEQs occurred south of the airport, with ranges of 76 and 331fg WHO-TEQ/PUF day and an average of 152fg WHO-TEQ/PUF day. Construction activities, including excavation and transportation of dioxin-contaminated soil north of the airport, have increased airborne PCDD/F and dl-PCB contamination and health risks. The average daily doses of PCDD/Fs and dl-PCBs through inhalation (ADDA) for residents located north of the airport were the highest (10.9 to 3434fg WHO-TEQ/kg BW/day and average: 597fg WHO-TEQ/kg BW/day). Residents located west of the airport faced lower health risks (13-123fg WHO-TEQ/kg BW/day and average: 39fg WHO-TEQ/kg BW/day). Residents south of the airport were exposed to a minimum of 6.2-107fg WHO-TEQ/kg BW/day, with an average of 28fg WHO-TEQ/kg BW/day. The maximum and average ADDA values for residents north of the airport exceeded 10% of the tolerable daily intake (TDI) recommended by the WHO (100-400fg WHO-TEQ/kg BW/day). In comparison, all the ADDA values for residents located west and south of the airport were less than and within 10% of the TDI.

Temporal trends (1972-2017) and spatial differences of persistent halogenated aromatic hydrocarbons in osprey eggs in Finland.

Time trends and regional differences of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), DDTs, polybrominated biphenyls (PBBs) and polybrominated diphenylethers (BDEs) were studied in unhatched osprey eggs collected by bird ringers in 1972-2017 from four areas in Finland. Two study areas were from Baltic Sea, Northern Quark and Finnish Archipelago Sea, while the two others were inland lake areas, eutrophicated Lake Vanajanselkä affected by industrial emissions, and Pristine SW Lake Area. The highest concentrations of most compound groups were in Lake Vanajanselkä consistent with high emissions, the predominance of bream as a prey, and higher concentrations in bream compared to other prey fish. Concentrations of all chlorinated compounds decreased significantly in all study areas. Average annual decreases were ∑PCDD/F 2.3-4.9%, ∑PCB 2.2-4.2%, ∑PCN 2.6-7.0% and ∑DDT 7.1-9.5%, primarily in line with decreased levels in prey fish. From 1972 PBBs and BDEs increased significantly until 1990s declining rapidly thereafter. PCDD/F congener profile was dominated by 2,3,4,7,8-PeCDF, except in Lake Vanajanselkä by 1,2,3,6,7,8-HxCDD. PCB congener profile was dominated by PCB 153 in all study areas, followed by PCB 180 and PCB 138. Among dioxin-like compounds PCBs contributed 82%, PCDDs 14% and PCDFs 4% to toxic equivalent quantity (∑TEQ). PCB 126 contributed most to ∑TEQ, followed by 1,2,3,7,8-PeCDD. BDE 47 being the dominant BDE congener, followed by BDE 100. ∑DDT concentrations were relatively similar across all study areas, with DDE contributing about 90%. Productivity of chicks per active nest was significantly decreased in Lake Vanajanselkä, and the likely explanation is embryotoxicity of dioxin-like compounds. It is plausible that dioxin-like compounds influenced embryonic survival among highly exposed ospreys prior to 2010, especially in Lake Vanajanselkä and Northern Quark. However, decreased survival due to DDE-induced eggshell thinning seems unlikely after 1985, and BDE levels were below those potentially causing adverse effects.

Polychlorinated biphenyls in the surface and deep waters of the Southern Indian Ocean and Coastal Antarctica

Polychlorinated biphenyl compounds (PCBs) are industrial chemicals whose production was discontinued in the early nineties in most countries. Sill, PCBs are detectable in pristine and remote locations. Occurrence in regions such as Southern Oceans and Antarctica are influenced by the global, and regional, cycling. Here, we studied the surface and deep ocean distribution of indicator- and dioxin-like PCB congeners in the Southern Indian Ocean (SIO), and the coast of Antarctica (COA) during the tenth Indian Southern Ocean Expedition (SOE-10), December 2017–February 2018. ∑21PCBs in SIO surface waters ranged from 3.8 to 167.1 pg L−1 (average ± standard deviation: 35.7 ± 48.4 pg L−1), and in COA from 1.0 to 41.8 pg L−1 (13.8 ± 12.7 pg L−1), respectively. A noticeable gradient was observed, with higher PCBs levels in northern latitudes than southern latitudes in the SIO, and higher levels in the eastern longitudes compared to western longitudes in the COA. Results suggest the influence of secondary sources, or re-emission, of PCBs in the Southern Oceans and Antarctica. Both regions showed notable PCB levels in surface and deep waters (up to 1000 m) due to ongoing surface sources and remineralization processes in deeper waters. Multimedia modeling with the global model (BETR-Global) suggests the SIO act as a net sink for PCBs in the ocean.

Temporal, spatial, and seasonal variations in airborne PCDD/F and dl-PCB concentrations around Bien Hoa hot spot, Vietnam, and health risk assessments

Passive air samplers were used to monitor polychlorodibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) between 2020 and 2022 in four residential areas around Bien Hoa hot spot (BHS) including Trung Dung (TD), Tan Phong (TP), Quang Vinh (QV), and Buu Long (BL). The total toxic equivalents of PCDD/Fs and dl-PCBs (∑TEQs) were highest in the TD area, from 284 to 642 fg TEQ/PUF day. Next was the QV area, where ∑TEQs ranged from 229 to 569 fg TEQ/PUF day. Then, ∑TEQs varied from 205 to 503 fg TEQ/PUF day in the TP area. The lowest ∑TEQs were between 179 and 385 fg TEQ/PUF day in the BL area. The temporal, spatial, and seasonal variations in concentrations of PCDD/Fs and dl-PCBs were related to the prevailing wind direction and the distance from each area to the dioxin hot spot. The average ∑TEQs for all four areas surrounding BHS in the dry season (423 fg TEQ/PUF day) were 1.4 times higher than in the rainy season (303 fg TEQ/PUF day). Health risk assessments from airborne dioxin exposure were estimated using the average daily doses through inhalation (ADDI). The ADDI for residents surrounding BHS ranged from 14.6 to 208 fg TEQ/kg BW/day. The ADDI values by areas were as follows: 23.2–208 fg TEQ/kg BW/day in the TD, 18.7–184 fg TEQ/kg BW/day in the QV, 16.7–163 fg TEQ/kg BW/day in the TP, and 14.6–125 fg TEQ/kg BW/day in the BL. These ADDI values remained within and below the 10% threshold of the WHO-recommended tolerable daily intake (100–400 fg TEQ/kg BW/day). It is necessary to control the excavation activities inside the BHS and cover the temporary storage sites of dioxin-contaminated materials to minimize the emissions of PCDD/Fs and dl-PCB into the ambient air.

Polychlorinated Biphenyls (PCBS)-induced oxidative stress and inflammation in human thyrocytes: involvement of AhR and NRF-2/HO-1 pathway.

In this in vitro study, we investigated the effects of polychlorinated biphenyls (PCBs) on human thyrocytes, with a focus on the involvement of AhR, a key player in xenobiotic response, and the anti-oxidant Nrf-2/HO-1 pathway. Primary cultured thyrocytes were exposed to the dioxin-like congeners PCB118 and PCB126 at 2.5 and 5 µM concentrations. mRNA expression was assessed by real-time PCR, and protein expression by Western Blot and ELISA, while protein quantification was assessed by densitometric analysis. In cultured thyrocytes, PCB118 and PCB126 induced a significant (P < 0.01) increase of mRNA and protein levels of the pro-inflammatory cytokines IL-1beta and IL-6, while reducing those of thyroglobulin (TG) and NIS (p < 0.05), indicating down-regulation of these thyroid-specific genes in PCB-induced inflammation. ROS production also increased (p < 0.001). mRNA levels of AhR and the downstream molecules cytochrome P4501A, Nrf-2/HO-1 increased (p < 0.001), as well as related protein levels (p < 0.01), suggesting the activation of AhR and Nrf-2 pathways in response to PCBs exposure. AhR silencing decreased AhR-related gene expression and restored NIS and TG expression, while reducing inflammatory cytokines and oxidative stress markers (p < 0.05). Dioxin-like PCBs (PCB118 and PCB126) may promote inflammation and oxidative stress in thyrocytes, impairing the expression of genes that are key players of thyroid function. These effects can be partially attributed to the activation of the AhR and Nrf-2 pathways. These data may contribute to explain the mechanisms underlying thyroid toxicity of PCBs, highlighting the potential role of these pollutants as a trigger of autoimmune thyroid inflammation and damage.

Tissue distribution and exposure risk assessment of dioxins, dioxin-like polychlorinated biphenyls and perfluoroalkyl substances in red swamp crayfish

Significant attention has been paid to the adverse effects of dioxins, dioxin-like polychlorobiphenyls (DL-PCBs) and per-and polyfluoroalkyl substances (PFAS) in environment and food on ecosystem and human health. However, limited information exists regarding the occurrence, tissue distribution and exposure risk of these pollutants in crayfish. This study investigated tissue-specific distribution characteristics, influence factors and exposure risk of dioxins, DL-PCBs and PFAS in crayfish. Dioxins, DL-PCBs, and PFAS were detected in crayfish samples, with concentrations ranging from 0.361 to 1.91 pg TEQ g−1 for sum dioxins and DL-PCBs, and 1.54–21.2 ng g−1 for sum PFAS. The highest concentrations of dioxins, DL-PCBs TEQ and total PFAS were found in crayfish viscera and accounting for over 69% of the relative body burden (RBBs) of these pollutants. The specific-tissue distribution of these pollutants linked to tissue fat and protein content and log Kow and molecular weights of homologues. The consumption of crayfish edible tissue posed no health risks from exposure to dioxins and DL-PCBs as well as sum 4 PFAS in adults. However, consumption of crayfish viscera significantly increased exposure risk. This study can provide valuable insights into the tissue-specific distribution and human exposure risks associated with dioxins, DL-PCBs and PFAS in crayfish.

3,3',4,4'-tetrachlorobiphenyl (PCB77) enhances human Kv1.3 channel currents and alters cytokine production.

Polychlorinated biphenyls (PCBs) were once used throughout various industries; however, because of their persistence in the environment, exposure remains a global threat to the environment and human health. The Kv1.3 and Kv1.5 channels have been implicated in the immunotoxicity and cardiotoxicity of PCBs, respectively. We determined whether 3,3',4,4'-tetrachlorobiphenyl (PCB77), a dioxin-like PCB, alters human Kv1.3 and Kv1.5 currents using the Xenopus oocyte expression system. Exposure to 10 nM PCB77 for 15 min enhanced the Kv1.3 current by approximately 30.6%, whereas PCB77 did not affect the Kv1.5 current at concentrations up to 10 nM. This increase in the Kv1.3 current was associated with slower activation and inactivation kinetics as well as right-shifting of the steady-state activation curve. Pretreatment with PCB77 significantly suppressed tumor necrosis factor-α and interleukin-10 production in lipopolysaccharide-stimulated Raw264.7 macrophages. Overall, these data suggest that acute exposure to trace concentrations of PCB77 impairs immune function, possibly by enhancing Kv1.3 currents.

Assessment of the Pollution Levels, Sources, and Exposure Risks of Polychlorinated Biphenyls (PCBs) in Urban Park Dusts within Lagos Metropolis

ABSTRACTPolychlorinated Biphenyls (PCBs) represent organic contaminants that are persistent hazardous, carcinogenic, and genotoxic, thereby endangering both human well‐being and the ecosystem. This research delved into concentration patterns, sources, and health hazards associated with PCBs in dust collected from vehicle parks in Lagos metropolis. PCBs in samples of Lagos park dust extended from 1.00 to 36.80 ng/g, with PCB 18 exhibiting the highest mean concentration of 17.02 ng/g. Among the 12 PCBs studied, 5 Cl atom PCBs contributed the highest percentage, constituting 30% of the total PCB content in Lagos park dust. Dioxin‐like PCBs (DLPCBs) made up 27% of the overall PCBs composition in the dust. Using the positive matrix factorization method, eight sources of PCBs were identified, with biomass combustion contributing the highest proportion at 42% of the total PCB emissions. Health risk estimates revealed that the magnitude of PCBs exposure in human followed the order: ingestion &gt; dermal contact &gt; inhalation. PCBs exposure through ingestion in children was 9.33 times higher than that of adults, potentially attributed to the inadvertent intake of dust particles by children via hand‐to‐mouth contact. Cancer risk assessments for all PCB congeners remained below 10−6, indicating acceptable risk levels. PCB 18 had the highest cancer risk values, reaching 8.69 × 10−9 for children and 1.19 × 10−9 for adults.

Screening legacy and emerging organic pollutants in the contaminated soil of Dhaka, Bangladesh

The current understanding of the legacy and emerging organic pollutants in the soil of Bangladesh remains limited. Inadequate disposal practices, particularly in e-waste, landfills, and industrial operations, may lead to the pervasive presence of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in the country. This study aimed to systematically investigate the concentrations, sources, and risk assessment of halogenated flame retardants (HFRs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), organochlorine pesticides (OCPs), chlorinated paraffins (CPs), and PAHs in the contaminated soil of Dhaka's dumpsites, e-waste, and industrial areas collected in 2017. The total concentration of investigated pollutants averaged at 4790 ± 4040 ng g−1 dw, with the following order: ∑44CPs (4110 ± 4140 ng g−1 dw) > ∑16PAHs (422 ± 491 ng g−1 dw) > ∑16HFRs (190 ± 538 ng g−1 dw) > ∑209PCBs (43.5 ± 73.5 ng g−1 dw) > ∑50PCNs (17.7 ± 21.0 ng g−1 dw) > ∑27OCPs (9.41 ± 9.61 ng g−1 dw). The e-waste site exhibited the highest total concentration of the target pollutants, reaching 12,700 ng g−1 dw. CPs were the predominant contributors, accounting for averages of 81.8%, 70.5%, and 68.5% to waste landfills, e-waste, and industrial sites, respectively. A comprehensive analysis of 209 PCB congeners revealed their primary origin from Aroclor PCBs, with minor contributions from unintentionally produced PCBs. The highest incremental lifetime carcinogenic risk (ILCR) occurred in e-waste sites, contributed by dioxin-like PCBs, with a maximum value of 5.9 × 10−5 for adults, exceeding the limit 1.0 × 10−6 set by the U.S. EPA. The non-carcinogenic hazard quotients (HQs) were much lower, suggesting no significant risk from the investigated pollutants. Our findings highlight the importance of proper waste management and regulated e-waste recycling to mitigate potential hazardous risks to the Bangladeshi population.

PCB169 exposure aggravated the development of non-alcoholic fatty liver in high-fat diet-induced male C57BL/6 mice.

Polychlorinated biphenyls (PCBs) are lipophilic environmental toxicants. Epidemiological studies have established a link between PCBs and both metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). Multiple studies have reported that exposure to both PCB156 and PCB126 among the 12 dioxin-like PCBs leads to the development of NAFLD. However, studies to elucidate whether PCB169 induces the development of NAFLD by constructing in vivo models have not been reported. Therefore, we evaluated the effects of exposure to PCB169 (5 mg/kg-bw) on hepatic lipid metabolism in C57BL/6 mice from control diet and high-fat diet cohorts. The results showed that PCB169 exposure reduced body weight and intraperitoneal fat mass in mice on the control diet, but the liver lipid levels were significantly increased, exacerbating NAFLD in mice on a high-fat diet. Through transcriptomics studies, it was found that PCB169 exposure induced significant up-regulation of Pparγ, Fasn, and Aacs genes involved in hepatic lipogenesis, as well as remarkable up-regulation of Hmgcr, Lss, and Sqle genes involved in cholesterol synthesis. Additionally, there was notable down-regulation of Pparα and Cpt1 genes involved in lipid β-oxidation, leading to abnormal lipid accumulation in the liver. In addition, we found that PCB169 exposure significantly activated the Arachidonic acid metabolism, PPAR signaling pathway, Metabolism of xenobiotics by cytochrome P450, and Retinol metabolism pathways, and so on. Our study suggests that PCB169 can modify gene expression related to lipid metabolism, augument lipid accumulation in the liver, and further contribute to the development of NAFLD, thereby revealing the detrimental effects associated with PCB exposure on animal growth and metabolism.

Association between Prenatal Dietary Toxicants and Infant Neurodevelopment: The Role of Fish.

More research is needed to understand how the maternal consumption of fish and fish-borne toxicants impacts infant neurodevelopment. The present analysis was conducted over 460 mother-infant pairs within the ECLIPSES study. Dietary intake of metals and persistent organic pollutants from fish (including white fish, blue fish, and seafood) was estimated in pregnant women. The infants underwent cognitive, language, and motor function assessments using the Bayley Scales of Infant Development-III at the 40-day postpartum. Associations between dietary toxicants and outcomes were assessed using multivariable linear regression models. Estimated prenatal exposure to fish-borne toxicants, such as arsenic, inorganic arsenic, methylmercury, dioxin-like polychlorinated biphenyls (DL-PCBs), and non-DL-PCBs, was associated with poorer language functions in infants, whereas no significant associations were found with motor or cognitive functions. Maternal fish consumption exceeding the Spanish recommendation of no more than 71 g per day was linked to these adverse effects on language abilities without affecting motor or cognitive development. This highlights the importance of vigilant monitoring of environmental toxicants and the provision of dietary guidance for pregnant women, with potential implications for public health and child development.

Serum concentration of polychlorinated biphenyls and the risk of type 2 diabetes: a 10-year follow-up historical cohort study

This study investigated the association between serum concentrations of Polychlorinated Biphenyls (PCBs) and the risk of type 2 diabetes within the general population. A ten-year follow-up historical cohort study was conducted during 2009–2019 as part of the Bushehr MONICA cohort study in Iran. Of 893 non-diabetes participants at base line, 181 individuals were included in the study. The concentration of nine PCB congeners was measured in individuals’ serum samples at baseline, and the risk of type 2 diabetes was determined based on fasting blood sugar at the end of follow-up. Multiple logistic regression models were used to assess the study outcomes after adjusting for covariates. This study included 59 diabetes individuals (32.6%; mean [SD] age: 58.64 [8.05]) and 122 non-diabetes individuals (67.4%; mean [SD] age: 52.75 [8.68]). Multivariable analysis revealed that a one-tertile increase (increasing from 33rd centile to 67th centile) in Σ non-dioxin-like-PCBs (OR 2.749, 95% CI 1.066–7.089), Σ dioxin-like-PCBs (OR 4.842, 95% CI 1.911–12.269), and Σ PCBs (OR 2.887, 95% CI 1.120–7.441) significantly associated with an increased risk of type 2 diabetes. The strongest association was obtained for dioxin-like PCBs. The results highlight a significant correlation between PCB exposure and an increased risk of type 2 diabetes. The evidence suggests that additional epidemiological studies are necessary to clarify the link between PCBs and diabetes.

A novel, low-cost, and efficient separation strategy based on S-doped C3N4 for the analysis of PCDD/Fs and dioxin-like PCBs

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) are widespread and highly toxic persistent organic pollutants with similar chemical structure. The popular process for the separation of PCDD/Fs and dl-PCBs in one sample often relies on imported and expensive activated carbon, giving rise to an urgent need of inexpensive and efficient separation method. Herein, a novel, simple, and low-cost separation strategy based on sulfur-doped carbon nitride (S-C3N4) is reported. The S-C3N4 material was synthesized through simple thermal annealing with precursor of thiocyanuric acid. After recovery experiments, the optimal addition ratio of S-C3N4 was determined to be 40% mixed with silica gel. The recoveries for PCDD/Fs and dl-PCBs congeners are 32% - 105% and 60% - 70% respectively, which not only meets USEPA and Chinese standards but also shows comparable performance to activated carbon. Moreover, the proposed S-C3N4 strategy exhibits excellent performance for the analysis of PCDD/Fs and dl-PCBs in real complex samples (sediment and fish liver) in terms of detected concentrations and toxic equivalents. Overall, this study puts forward a new and low-cost avenue for the separation of PCDD/Fs and dl-PCBs, which is of remarkable meaning for motivating the development of detection techniques and domestic equipment for dioxins and other pollutants in the environment.

Human biomonitoring of dioxins, furans, and non-ortho dioxin-like polychlorinated biphenyls (PCBs) in blood plasma from Old Crow, Yukon, Canada (2019)

Dioxins, furans, and dioxin-like polychlorinated biphenyls (PCBs) are a group of persistent and toxic chemicals that are known to have human health effects at low levels. These chemicals have been produced for commercial use (PCBs) or unintentionally as by-products of industry or natural processes (PCBs, dioxins, and furans). Additionally, dioxin-like PCBs were formerly used in electrical applications before being banned internationally (2004). These chemicals are widely dispersed in the environment as they can contaminate air and travel hundreds to thousands of kilometers before depositing on land or water, thereafter, potentially entering food chains. Community concerns surrounding the safety of traditional foods prompted a human biomonitoring project in Old Crow, Yukon Territory (YT), Canada (2019). Through collaborative community engagement, dioxins and like compounds were identified as a priority for exposure assessment from biobanked samples.In 2022, biobanked plasma samples (n = 54) collected in Old Crow were used to measure exposures to seven dioxins, ten furans, and four dioxin-like PCBs. 1,2,3,6,7,8-HxCDD, 1,2,3,7,8,9-HxCDD, 1,2,3,4,6,7,8-HpCDD, OCDD, 2,3,4,7,8-PeCDF, 1,2,3,6,7,8-HxCDF, PCB 126, and PCB 169 were detected in at least 50 % of samples. Among these analytes, the only congener at elevated levels was PCB 169, which was approximately ∼2-fold higher than the general population of Canada. No significant sex-based or body mass index (BMI) differences in biomarker concentrations were observed. Generally, the concentrations of the detected congeners increased with age, except for 1,2,3,4,6,7,8-HpCDD.For the first time, this research measures dioxin and like-compound exposures in Old Crow, advancing the information available on chemical exposures in the Arctic. Further research could be directed towards the investigation of PCB 169 exposure sources and temporal monitoring of exposures and determinants.