Dietary intake of non-dioxin-like PCBs (NDL-PCBs) in France, impact of maximum levels in some foodstuffs

Early-life exposure to PCBs and PFAS exerts negative effects on the developing central nervous system

Persistent organic pollutants (POPs) are ubiquitous in the environment and display the capacity to bioaccumulate in living organisms, constituting a hazard to both wildlife and humans. Although restrictions have been applied to prohibit the production of several POPs since the 1960s, high levels of these compounds can still be detected in many environmental and biological matrices, due to their chemical properties and significantly long half-lives. Some POPs can be passed from mother to the fetus and can gain entry to the central nervous system (CNS), by crossing the blood-brain barrier (BBB), resulting in significant deleterious effects, including neurocognitive and psychiatric abnormalities, which may lead to long-term socio-economic burdens. A growing body of evidence obtained from clinical and experimental studies has increasingly indicated that these POPs may influence neurodevelopment through several cellular and molecular mechanisms. However, studies assessing their mechanisms of action are still incipient, requiring further research. Polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS) are two of the main classes of POPs associated with disturbances in different human systems, mainly the nervous and endocrine systems. This narrative review discusses the main PCB and PFAS effects on the CNS, focusing on neuroinflammation and oxidative stress and their consequences for neural development and BBB integrity. Moreover, we propose which mechanisms could be involved in POP-induced neurodevelopmental defects. In this sense, we highlight potential cellular and molecular pathways by which these POPs can affect neurodevelopment and could be further explored to propose preventive therapies and formulate public health policies.

PCBs contamination in water and Mytilus edulis along the north Portuguese Atlantic Ocean coastline and analysis of potential carcinogenic risk to human health

Seven seawater polychlorinated biphenyls (PCBs) were measured in water (DAP), suspended particulate matter (SPM), and blue mussels (Mytilus edulis) collected from four beaches in northwest Portugal. PCBs were extracted using solid-phase-extraction, ultrasound-extraction and QuEChERS before GC-MS analysis. The two-year annual average concentrations of PCBs in DAP, SPM and the four-year analysis in mussels were ∼ 4.4 ng/L, ∼15.9 μg/kg, and ∼ 56.0 μg/kg. The results suggest higher concentrations of PCBs in summer for SPM and in spring for mussels, mainly those collected close to the Ave River estuary. The origins of PCBs remain uncertain. Risk assessment shows that PCBs in water are unlikely to harm local biota due to their low thyroid hormone toxicity equivalents (TEQ-TH; ∼1.4E-04 ng/L and ∼ 4.1E-04 μg/kg) and on WHO toxicity equivalents (TEQ-WHO; ∼2.1E-05 ng/L and ∼ 4.9E-05 μg/kg). However, the lifetime carcinogenic risk (LCR) for humans consuming local bivalves is concerning, as it exceeds 1.0E-06.

Trajectories of long-term exposure to PCB153 and Benzo[a]pyrene (BaP) air pollution and risk of breast cancer

BACKGROUND

While genetic, hormonal, and lifestyle factors partially elucidate the incidence of breast cancer, emerging research has underscored the potential contribution of air pollution. Polychlorinated biphenyls (PCBs) and benzo[a]pyrene (BaP) are of particular concern due to endocrine-disrupting properties and their carcinogenetic effect.

OBJECTIVE

To identify distinct long term trajectories of exposure to PCB153 and BaP, and estimate their associations with breast cancer risk.

METHODS

We used data from the XENAIR case-control study, nested within the ongoing prospective French E3N cohort which enrolled 98,995 women aged 40-65 years in 1990-1991. Cases were incident cases of primary invasive breast cancer diagnosed from cohort entry to 2011. Controls were randomly selected by incidence density sampling, and individually matched to cases on delay since cohort entry, and date, age, department of residence, and menopausal status at cohort entry. Annual mean outdoor PCB153 and BaP concentrations at residential addresses from 1990 to 2011 were estimated using the CHIMERE chemistry-transport model. Latent class mixed models were used to identify profiles of exposure trajectories from cohort entry to the index date, and conditional logistic regression to estimate their association with the odds of breast cancer.

RESULTS

5058 cases and 5059 controls contributed to the analysis. Five profiles of trajectories of PCB153 exposure were identified. The class with the highest PCB153 concentrations had a 69% increased odds of breast cancer compared to the class with the lowest concentrations (95% CI 1.08, 2.64), after adjustment for education and matching factors. The association between identified BaP trajectories and breast cancer was weaker and suffered from large CI.

CONCLUSIONS

Our results support an association between long term exposure to PCB153 and the risk of breast cancer, and encourage further studies to account for lifetime exposure to persistent organic pollutants.

Quantitative characterization of resident' exposure to typical semi-volatile organic compounds (SVOCs) around a non-ferrous metal smelting plant

To comprehensively characterize residents' exposure to major semi-volatile organic compounds (SVOCs), samples of indoor floor wipes, size-segregated airborne particles, gaseous air, food, and paired skin wipes were simultaneously collected from residential areas around a large non-ferrous metal smelting plant as compared with the control areas, and three typical SVOCs (including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and halogenated PAHs (HPAHs)) were determined. Comparison and correlation analysis among matrices indicated PAHs were the major contaminants emitted from metal smelting activities compared to HPAHs and PCBs, with naphthalene verified as the most important characteristic compound, and their accumulation on skin may be a comprehensive consequence of contact with floor dust and air. While patterns of human exposure pathways for the SVOCs were found to be clearly correlated to their vapor pressure, dermal absorption was the major contributor (51.1-76.3%) to total carcinogenic risk (TCR) of PAHs and HPAHs for surrounding residents, especially for low molecular weight PAHs, but dietary ingestion (98.6%) was the dominant exposure pathway to PCBs. The TCR of PAHs exceeded the acceptable level (1 × 10-4), implying smelting activities obviously elevated the health risk. This study will serve developing pertinent exposure and health risk prevention measures.

Analysis of polychlorinated biphenyls (PCBs) in edible oils using the QuEChERS/GC-MS method: A health risk assessment study

Population growth has made it difficult to provide safe food; because various toxic substances such as polychlorinated biphenyls (PCBs) can contaminate food products such as edible oils which have very high-rate consumption worldwide. Aims of study are to determine the concentration of PCBs in edible oil samples and to evaluate the carcinogenic risk of PCBs in them among Iranian people by Monte Calo Simulation (MCS). After finding the location of high customer hyper market in Tehran, 42 samples of 7 various types of edible oils were collected; then PCBs content of them measured using the modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction method and GC/MS technique. According to the findings the mean level of NDL-PCB in oil samples were ranged from 1.88 to 25.62 ng/g fat. Results of uncertainty analysis showed that among children the 95th percentile of Incremental Lifetime Cancer Risk (ILCR) were 7.80E-3, 5.37E-4, 5.37E-4, 2.00E-3, 1.59E-3, 13.9E-3 and 7.04E-4 for animal oil, corn oil, frying oil, olive oil, bran oil, sesame oil and sunflower oil, respectively. Also, the 95th percentile of ILCR among adults were 4.12E-2, 3.04E-3, 3.09E-3, 1.06E-2, 8.43E-3, 7.38E-3 and 3.74E-3 for animal oil, corn oil, frying oil, olive oil, bran oil, sesame oil and sunflower oil, respectively. The risk evaluation showed that in all edible oils the 95th percentile of simulated ILCR were more than 10-5, so it can be threatening health among both aging groups, although, the producers don't deliberately subject the users' lives to such danger, but high consumption rate and accumulation of PCBs in body tissues are contribute to increasing carcinogenic risk. Also, the 95th percentile of ILCR among adults were more than children, because the edible oil ingestion rate among adults was more than children.

Distribution, bioaccumulation, and health risk assessment of organochlorines across the riverine ecosystem of Punjab Province, Pakistan

This study was designed to assess the distribution of organochlorines (OCs) in fish species, their spatio-temporal variations, bioaccumulation potential, and associated human health risks via dietary intake. The levels of twenty-three organochlorine pesticides (OCPs) and thirty-five polychlorinated biphenyls (PCBs) were analyzed in six fish species collected from the riverine ecosystem of Punjab Province, Pakistan. The results indicated that the mean levels of Σ23OCPs were 74.1 ng/g ww and 184 ng/g ww, and for Σ35PCBs the levels were 38.8 ng/g ww and 74.8 ng/g ww in herbivorous and carnivorous fish species, respectively. The most abundant contaminants in all fish species were DDTs (65%) and HCHs (14%) among OCPs and heavier PCB congeners (62%) among PCBs. As for dioxin-like PCBs, the WHO toxic equivalency values (ng TEQ/g ww) were in the range of 0.21 (Cyprinus Carpio) to 2.38 (Rita Rita), exceeding the maximum allowable limit of 0.004 ng TEQ/g, ww by the European Commission. Spatio-temporal analysis indicated relatively higher OC levels in winter season with elevated concentrations in fish samples from industrial zone. The bioconcentration factor (L/kg) values ranged from 723 to 2773 for PCBs and 315 to 923 for OCPs in all fish species, with higher levels were reported in carnivorous species. The human health risk assessment at both 50th and 95th percentiles revealed the absence of any significant non-carcinogenic risk as calculated HR was less than 1. However, the critical carcinogenic risk was found to be associated for most of the contaminants, signifying the dietary exposure to OCPs and PCBs might pose the public health concern.

Organochlorine pesticides and polychlorinated biphenyls in raw bovine milk from various dairy farms in Beja, Tunisia: contamination status, dietary intake, and health risk assessment for the consumers

We determined organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in raw bovine milk taken directly from the milking equipment for different animals and various farms in Béja region, which is one of the largest milk producing areas in Tunisia. All milk samples were contaminated with one or more pesticides and exhibited measurable concentrations of some PCB congeners. The residue levels are generally marked by the predominance of dichlorodiphenyltrichloroethanes (DDTs) (median: 17.60 ng g^-1 fat), followed by hexachlorobenzene (HCB) (median: 14.31 ng g^-1 fat), PCBs (median: 4.71 ng g^-1 fat), and hexachlorocyclohexanes (HCHs) (median: 0.77 ng g^-1 fat). DDT/DDE ratios across the samples vary between 0.09 to 32.24 and exhibit the hypothesis of sustaining illegal use of the banned pesticide. The historical or recent use of OCPs and possible emission sources of PCBs identified near studied farms may lead to increased levels of these contaminants in produced milk. The estimated daily intake (EDI) values were several orders of magnitude below the tolerable daily intake (TDI) fixed by FAO/WHO, though recorded concentration in some samples exceeded the maximum residue limits (MRLs) fixed by the EU, especially for OCPs. According to health risk assessments, consumption of raw milk did not pose an obvious cancer risk or other health problems for local inhabitants.

A Facile and Rapid Strategy for Quantifying PCBs in Cereals Based on Dispersive Solid-Phase Extraction and Gas Chromatography-Mass Spectrometry: A Reference for Safety Concerns in Sustainable Textiles

Cereals and their derivative products such as starch and cyclodextrin are significant natural materials for sustainable textile processing (e.g., sizing, dispersing, etc.). However, the contamination of cereals with polychlorinated biphenyls (PCBs) is often neglected, which has led to increasing concerns due to the adverse effects on end users. Therefore, monitoring PCBs in cereals is of great importance in preventing health risks. However, high starch, protein, and fat contents make cereals a complicated matrix and can challenge the analysis of PCBs in cereals. This work describes a facile and rapid strategy for quantifying 18 PCBs in cereals that included corn, wheat, and rice through dispersive solid-phase extraction and gas chromatography with mass spectrometry. Importantly, this was the first time that carboxyl-modified, multi-walled carbon nanotubes were incorporated in the detection of PCBs in cereals. The influences of several parameters on the extraction and clean-up efficiency were investigated; these included the type and volume of extraction solvent, sonication time, and the type and dosage of the adsorbent. The matrix effects on quantification were also evaluated. This approach exhibited a better clean-up performance. All the analytes showed weak matrix effects, and thus a solvent standard plot could be prepared for their quantification. Spiking experiments in the selected matrices at three concentration levels from 0.5 to 10 μg/kg resulted in satisfactory recoveries that ranged from 79.2% to 110.5% with relative standard deviations (RSDs; n = 6) less than 10.3%. The limits of detection (LODs) and quantification (LOQs) ranged from 0.04 to 0.1 μg/kg and 0.1 to 0.4 μg/kg, respectively. The practical application of this method was investigated by analyzing actual cereal samples, which demonstrated that the proposed approach was a facile and efficient strategy for PCB determination and provided a reference for the safety evaluation of sustainable textiles. The method also could be generalized to other troublesome samples for testing of multiple PCBs.

Active and passive biomonitoring of trace elements, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in small Mediterranean harbours

Pollution particularly affects coastal ecosystems due to their proximity to anthropic sources. Among those environments, harbours are subjected to marine traffic but also to accidental and chronic pollution. These areas are thus exposed to complex mixtures of contaminants such as trace elements and organic contaminants which can impact marine species, habitats, and ecosystem services. The monitoring of these compounds is thus a crucial issue for assessment of environmental health. In this context, the aim of the present work was to evaluate the chemical contamination of harbours in Corsica (NW Mediterranean) by measuring the bioaccumulation of trace elements, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in mussels, limpets, and sea cucumbers. The human health risks associated with seafood consumption were also assessed. Results reveal a relatively low contamination in the Corsican harbours studied compared to larger Mediterranean ports and suggest that the potential health risk for consumers eating seafood is low.

Presence of novel and legacy flame retardants and other pollutants in an e-waste site in China and associated risks

Electrical and Electronic Equipment (EEE) residues and their management have been widely identified as potential sources of plasticizers and flame retardants to the environment, especially in non-formal e-waste facilities. This study evaluates the distribution, partitioning and environmental and human impact of organophosphate esters (OPEs), legacy polychlorinated biphenyls (PCBs), polybromodiphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in the e-waste recycling area of Baihe Tang village, in the Qingyuan county, Guangdong province, China. A plastic debris lump accumulated in a small pond during years was identified as the main source of pollution with ∑pollutants of 8400 μg/g dw, being OPEs the main contaminants detected, followed by PBDEs. This lump produced the contamination of water, sediments, soils and hen eggs in the surrounding area at high concentrations. Plastic-water and water-sediment partitioning coefficients explained the migration of OPEs to the water body and accumulation in sediments, with a strong dependence according to the K_OW. Triphenyl phosphate (TPhP), tricresyl phosphate (TCPs) and high chlorination degree PCBs produced a risk in soils and sediments, considering the lowest predicted no effect concentration, while the presence of PCBs and PBDEs in free range hen eggs exceeded the acceptable daily intake. OCPs were detected at low concentrations in all samples. The presence of organic contaminants in e-waste facilities worldwide is discussed to highlight the need for a strict control of EEE management to minimize environmental and human risks.

Levels of non-dioxin-like PCBs (NDL-PCBs) in liver of loggerhead turtles (Caretta caretta) from the Tyrrhenian Sea (Southern Italy)

The levels of six non-dioxin-like polychlorinated biphenyls (PCBs 28, 52, 101, 138, 153, and 180) were determined in the liver of 84 loggerhead turtles (Caretta caretta) stranded along the coasts of the Tyrrhenian Sea in Campania Region (Southern Italy), from 2017 to 2021. The average value of the sum (∑₆PCB_IND) was 28.0 ± 52.2 ng/g (w.w.). The hexachlorobiphenyls PCB 153 and PCB 138 and the heptachlorobiphenyl PCB 180 were the main contributors to the ∑₆PCB_IND. A weak positive correlation was found between CCL and highly chlorinated PCBs, with adult females having lower PCB concentrations than juvenile females and adult males. This study provides more comprehensive information on the levels of NDL-PCB in Mediterranean loggerhead turtles and sets the basis for assessing anthropogenic impacts on this species.

Update of Indicator PCB Levels in Food in Southern Italy: Assessment of the Dietary Exposure for Adult and Elderly Population

The levels of non-dioxin-like PCB indicators (iPCBs 28, 52, 101, 138, 153, and 180) were determined in food samples (seafood, meat and processed meat, milk and dairy products, hen eggs, olive oil, and other fats) to evaluate the exposure of adult and elderly population. iPCB levels in samples were in the following order: fishery products > meat and processed meat > milk and dairy products > olive oil and other fats. None of the samples had concentrations above the maximum permissible limits for human consumption established by the European Union legislation, except for salami samples. The dietary intake for the total population was 12.33 ng·kg−1 bw·d−1, while depending on the sex/age groups, exposure was estimated between 9.60 and 12.11 ng·kg−1 bw·d−1, with seafood being the major contributor. The exposure scenario indicates that further efforts must still be carried out to protect the consumer from these harmful chemicals.

Transfer of Non-Dioxin-Like Polychlorinated Biphenyls (ndl-PCBs) from Feed and Soil into Hen Eggs

Understanding the transfer of non-dioxin-like polychlorinated biphenyls (ndl-PCBs) into foods of animal origin is crucial for human health risk assessment. In two experiments, we investigated the transfer of ndl-PCBs from contaminated feed and soil into eggs and meat of laying hens. The transfer from the feed was investigated with 30 laying hens. The treated hens were divided into two groups fed a contaminated diet (12.8 μg/kg sum of indicator ndl-PCBs; 88% dry matter (DM)) for 28 and 63 days, respectively, and then experienced a depuration period of 100 days with control feed. The transfer from soil was investigated with 72 laying hens kept in three separate outdoor pens (with three levels of ndl-PCB soil contamination) for 168 days. In both experiments, eggs were collected and analyzed for ndl-PCBs. In the second experiment, animals (n = 3 at the beginning, n = 6 per group after 42, 84, and 168 days) were slaughtered to determine ndl-PCBs in meat (breast muscle tissue) fat. The transfer of ndl-PCB from both feed and soil was clearly measurable and concentrations in eggs quickly exceeded maximum levels. Clear differences between individual congeners were observed. In particular, the low-chlorinated ndl-PCBs 52 and 101 are hardly found in eggs, despite their relatively high concentration in feed and soil. PCBs 138, 153, and 180, on the other hand, were found in large proportions in eggs and meat.

Exposure sources of polychlorinated biphenyls (PCBs) and health risk assessment: a systematic review in Iran

This systematic review aims to identify the sources of exposure to polychlorinated biphenyls (PCBs), portioning, and human health risk assessment in Iran. The literature was searched in the international databases of Web of Science, PubMed, Scopus, Google Scholar, and the national databases of SID and MagIran up to November 14, 2020. Among all 153 articles, 21 eligible papers were identified. Among them, only one article was related to drinking water, the rest was related to food and soil, and no article was found on ambient air. The corrected portion of each exposure source was determined to be 90% for food, 9% for water, and 1% for air. The total hazard quotient (HQ) was determined to be within an unsafe range, and the total excess lifetime cancer risk (ELCR) was determined to be at a high risk of oral carcinogenesis. It is suggested that a comprehensive study be conducted in a specific period for all sources of exposure in all counties of Iran. Moreover, it is recommended that the policymakers set national standards for this pollutant in near future in some sources of exposure (e.g., drinking water) which have no standards in Iran.

In vitro effects of polychlorinated biphenyls and their hydroxylated metabolites on the synthesis and metabolism of iodothyronines in the chicken (Gallus domesticus) thyroid gland

To assess the effect of polychlorinated biphenyls (PCBs) and their hydroxylated metabolites (OH-PCBs) on thyroid hormone [TH: thyroxine (T₄) and triiodothyronine (T₃)] secretion, the concentrations of iodothyronine deiodinases (DIO1, DIO2, DIO3), and mRNA expression of genes involved in TH synthesis (TSHR, NIS, TPO, TG), metabolism (DIO1, DIO2, DIO3), and transport (OATP1C1, MCT8, MCT10, LAT1), chicken thyroid explants were incubated in medium supplemented with TSH (250 mU/ml), PCB118, PCB153, 4-OH-PCB107, and 3-OH-PCB153 (0.5 × 10^-8 M), and TSH together with each PCB and OH-PCB. The results of the in vitro experiment revealed that, except for 4-OH-PCB107, all applied PCBs and OH-PCBs inhibited basal and TSH-stimulated T₄ secretion. Moreover, they increased basal and reduced TSH-stimulated T₃ secretion. PCBs and OH-PCBs decreased the TSH-stimulated TSHR expression. Following PCB and OH-PCB exposure, significant changes in mRNA expression of NIS, TPO, and TG were observed. PCBs and OH-PCBs affected DIO1 and DIO3 transcript levels and protein abundances of each DIO. Furthermore, PCB-dependent effects on OATP1C1, MCT8, and MCT10 mRNA expression were found. In conclusion, both PCB118 and PCB153 and their OH-PCBs affect TH synthesis and deiodination processes in the chicken thyroid gland and influence TH transport across the thyrocyte membrane. In addition, the effects of PCBs and OH-PCBs depended mainly on the type of PCB congener and the exposure time. These results indicate that not only parental PCBs but also OH-PCBs are hazardous for the thyroid gland and may disrupt its endocrine function. Further studies are necessary to explain a mechanism of PCB and OH-PCB action in the avian thyroid gland.

Brominated and chlorinated contaminants in food (PCDD/Fs, PCBs, PBDD/Fs PBDEs): Simultaneous determination and occurrence in Italian produce

Validated methodology for the simultaneous determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs) in foods of animal origin is presented. Method performance indicators were equivalent or better than those required for the control of EU regulated (EU, 2017/644) PCDD/F and PCB congeners in these foods, and for risk assessment through dietary intake. The method uses a high (>90%) proportion of ¹³Carbon-labelled surrogates for internal standardisation combined with high resolution mass spectrometry that allow accurate quantitation, and this was confirmed by multiple successful participations in proficiency testing for PCDD/Fs, PCBs and PBDEs in food. The same validation and method performance requirements as used for PCDD/Fs were followed for PBDD/Fs. The analysis of a range of food samples (eggs, milk, fish, shellfish, pork, beef and poultry), showed the occurrence of all four classes of contaminants at varying concentration ranges. In general, PCBs were the most prominent contaminant, both, in terms of dioxin-like toxicity, as well as in the occurrence of non-dioxin-like congeners, an observation that concurs with those made in other studies on Italian foods. The levels of PCDD/F and PCB occurrence are consistent with a gradual decline in contamination as reported by some other similar studies. Although all the determined contaminants were detected in the sampled foods, there was poor correlation between the occurrences of the brominated and chlorinated contaminants, and between PBDEs and PBDD/Fs, but better associations were observed between the occurrences of the chlorinated contaminants.

Oyster Crassostrea gigas, a good model for correlating viral and chemical contamination in the marine environment

To establish a relationship between viruses and chemicals, they were analysed in oyster Crassostrea gigas from an Italian experimental station. The chemicals concentrations were: Σ6 NDL-PCBs 0.82-7.12 ng g^-1; BaP LOQ (<0.2 μg kg^-1) to 1.2 μg kg^-1; PAH4 LOQ (<0.2 μg kg^-1) to 9.8 μg kg^-1; Cd 0.073-0.365 mg kg^-1; Pb 0.010-0.487 mg kg^-1; and Hg < LOQ (0.089 mg kg^-1). The viruses identified included: noroviruses (NoVGI/GII), astrovirus (AsV), rotavirus (RV), adenovirus (AdV), and sapovirus (SaV), while hepatitis A, hepatitis E, and Aichi viruses were not detected. Significant correlations were observed for NDL-PCBs with NoVGI, NoVGII, and AdV; BaP and PAH4 with NoVGI and AsV; Cd with RV; Pb with NoVGI and AsV; PAHs with Pb; AsV with NoVGI; and AdV with NoVGII. The study indicated as C. gigas is a model for correlating pollutants and foodborne viruses, whose co-presence may represent an additional food safety risk.

Decreases in Concentrations and Human Dietary Intakes of Polychlorinated Biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) in Korean Seafood Between 2005 and 2017

Concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in 23 seafood species widely consumed by the Korean population in the periods of 2005-2007, 2010-2011, and 2015-2017. The Σ₈₂PCB (sum of 82 PCB congeners) and Σ₁₉PBDE (sum of 19 PBDE congeners) concentrations in the seafood samples of 2015-2017 were 0.06-6.69 ng/g wet weight and 0.01-1.60 ng/g wet weight, respectively. The Σ₈₂PCB and Σ₁₉PBDE concentrations in the samples were significantly correlated. Elevated PCB and PBDE concentrations were found in fatty fish, such as herring, mackerel, and tuna. The current human intakes of PCBs and PBDEs were much lower than the tolerable daily intake or lowest observed adverse effect level. The levels and human dietary intakes of PCBs and PBDEs in the 2015-2017 survey showed decreases of 17-73% and 57-86%, respectively, compared with those in 2005-2007 and 2010-2011 surveys. This indicates that global bans on PCBs and PBDEs have been effective, and their levels and human exposure to them have been gradually declining.

Long-term atmospheric exposure to PCB153 and breast cancer risk in a case-control study nested in the French E3N cohort from 1990 to 2011

BACKGROUND

Although the genetic and hormonal risk factors of breast cancer are well identified, they cannot fully explain the occurrence of all cases. Epidemiological and experimental studies have suggested that exposure to environmental pollutants, especially those with potential estrogenic properties, as polychlorinated biphenyls (PCBs) may have a role in breast cancer development. Being the most abundantly detected in human tissues and in the environment, congener 153 (PCB153) is widely used in epidemiological studies as indicator for total PCBs exposure.

OBJECTIVES

We aimed to estimate the association between cumulative atmospheric exposure to PCB153 and breast cancer risk.

METHODS

We conducted a case-control study of 5222 cases and 5222 matched controls nested within the French E3N cohort from 1990 to 2011. Annual atmospheric PCB153 concentrations were simulated with the deterministic chemistry-transport model (CHIMERE) and were assigned to women using their geocoded residential history. Their cumulative PCB153 exposure was calculated for each woman from their cohort inclusion to their index date. Breast cancer odds ratios (ORs) associated with cumulative PCB153 exposure and their 95% confidence intervals (95% CIs) were estimated using multivariate conditional logistic regression models.

RESULTS

Overall, our results showed a statistically significant linear increase in breast cancer risk related to cumulative atmospheric exposure to PCB153 as a continuous variable (adjusted OR = 1.19; 95% CI: 1.08-1.31, for an increment of one standard deviation among controls (55 pg/m³)). Among women who became postmenopausal during follow-up, the association remained statistically significant (adjusted OR = 1.23; 95% CI: 1.09-1.39). In analyses by hormone receptors status, the positive association remained significant only for ER-positive breast cancer (adjusted OR = 1.18; 95% CI: 1.05-1.33).

DISCUSSION

This study is the first to have estimated the impact of atmospheric exposure to PCB153 on breast cancer risk. Our results showed a statistically significant increase in breast cancer risk, which may be limited to ER-positive breast cancer. These results warrant confirmation in further independent studies but raise the possibility that exposure to PCB153 increase breast cancer risk.

Human exposure to PCBs, PBDEs and bisphenols revealed by hair analysis: A comparison between two adult female populations in China and France

Humans are exposed to various anthropogenic chemicals in daily life, including endocrine-disrupting chemicals (EDCs). However, there are limited data on chronic, low-level exposure to such contaminants among the general population. Here hair analysis was used to investigate the occurrence of four polychlorinated biphenyls (PCBs), seven polybrominated diphenyl ethers (PBDEs) and two bisphenols (BPs) in 204 Chinese women living in the urban areas of Baoding and Dalian and 311 pregnant French women. All the PCBs and PBDEs tested here were more frequently detected in the hair samples of the French women than in those of the Chinese women. In both cohorts, PCB 180 and BDE 47 were the dominant PCB and PBDE congener, respectively. PCB 180 was found in 82% of the French women and 44% of the Chinese women, while the corresponding values of BDE 47 were 54% and 11%, respectively. A discriminant analysis further demonstrated the difference in PCBs and PBDEs exposure profile between the two cohorts. These results demonstrate that hair analysis is sufficiently sensitive to detect exposure to these pollutants and highlight differences in exposure between populations even at environmental levels. Although BPA and BPS were found in 100% of the hair samples in both cohorts, the French women had significantly higher levels of BPA and BPS than the Chinese women. The median concentrations of BPA were one order of magnitude higher than BPS in both the Chinese (34.9 versus 2.84 pg/mg) and the French women (118 versus 8.01 pg/mg) respectively. Our results suggest that both French and Chinese populations were extensively exposed to BPA and BPS.

Spatial and temporal trends of polychlorinated biphenyls in water and sediment from Nairobi River, Kenya

Polychlorinated biphenyls (PCBs) are chemicals that have become ubiquitous environmental pollutants due to their past use, persistence, and long-range transport thus requiring continuous monitoring. Therefore, this research was carried out to investigate spatial and temporal trends of seven indicator PCBs and two others (PCB 105 and PCB 156) in the Nairobi River. Levels of PCBs ranged from below detection limit (bdl) to 157.64 ± 1.52 ng g^-1 and bdl to 718.78 ± 1.71 ng L^-1 for sediment and water, respectively. PCBs 28, 138, and 153 were the most dominant contributing 33.4%, 17.9%, and 14.5% to the total PCBs in sediments and 54.6%, 19.3%, and 14.1% to the total PCBs in water. There was a general increase in ΣPCBs from 18.89 to 151.18 ng g^-1 for sediments and 275.52 to 429.84 ng L^-1 for water as the River flowed downstream. The dry season recorded the highest ΣPCB in sediments while the rainy season recorded the highest ΣPCBs in water, with levels exceeding the WHO water quality guidelines. Risk assessment revealed that populations living downstream are exposed to high levels of PCBs through the consumption of water. Levels of ΣPCBs downstream also exceeded the sediment quality guidelines meaning that aquatic organisms are threatened.

Legacy and Emerging Contaminants in Demersal Fish Species from Southern Norway and Implications for Food Safety

The present study aimed at measuring the levels of legacy and emerging contaminants in fillet samples from four demersal fish caught in two fishing sites from Southern Norway, in order to assess possible implications for food safety. Levels of organochlorine compounds (OCs), organophosphate pesticides (OPs), polychlorinated biphenyls (PCBs), polybromodiphenyl ethers (PBDE), per- and polyfluoroalkyl substances (PFASs), and polycyclic aromatic hydrocarbons (PAHs) were measured in fillet from Atlantic cod (Gadus morhua), European plaice (Pleuronectes platessa), lemon sole (Microstomus kitt), and European flounder (Platichthys flesus) specimens. A negligible contamination by all the investigated chemicals was noted in both the fishing sites, as very low levels of OCs, PCBs, and PFASs were noted in a limited number of individuals for each species. Considering the levels of contaminants measured in fillets of the four demersal fish species, negligible risk for human health for Norwegian consumers can be supposed.

DPSIR Model Applied to the Remediation of Contaminated Sites. A Case Study: Mar Piccolo of Taranto

The study critically analyses the complex situation of the Mar Piccolo of Taranto (South of Italy), considered one of the most polluted marine ecosystems in Europe. In order to investigate possible cause–effect relationships, useful to plan appropriate planning responses or remediation technologies to be adopted, the Driver–Pressure–State–Impact–Response (DPSIR) model was applied. Methodologically, about 100 references have been considered, whose information was organized according to the logical scheme of the DPSIR. The results showed how the Mar Piccolo is the final receptor of pollutants coming from all industrial and agricultural activities, especially due to its natural hydrogeological network conformation. The anthropic activity represents a critical impact on the ecosystem due to the subsequent marine litter. The mobility of contaminants from sediments to the water column showed the potential risk related to the bioaccumulation of organisms from different trophic levels, posing a threat of unacceptable magnitude to human safety. The paper concludes by discussing the actions currently implemented by the authorities in response to the anthropogenic impacts as well as the need for new ones concerning both plans, programs, and remediation interventions. The case study shows how the DPSIR is a useful framework to organize extensive and heterogeneous information about a complex environmental system, such as the one investigated. This preliminary organization of the available data can represent the starting point for the development of a DPSIR-based Environmental Decision Support System (EDSS) with robust cause–effect relationships.

Nutritional Value and Contaminant Risk Assessment of Some Commercially Important Fishes and Crawfish of Lake Trasimeno, Italy

The aim of our study was to describe the balance between health benefits and risks associated with the consumption of crawfish and nine fish species from lake Trasimeno. We thus determined both fatty acid profiles (particularly, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids) and chemical pollutants (some polychlorinated biphenyls, pesticides, and heavy metals) in fish muscle tissues. The contents of all fatty acids varied significantly among species. Sand smelt, carp, and tench, which have a high fat content, contained considerable amounts of EPA and DHA; lean fish, like perch, pike, and largemouth bass, which have relatively high percentages of the predominant n-3 fatty acids EPA and DHA, showed lower amounts of these fatty acids because of their low lipid contents. Some species contributed strongly to the Dietary Reference Intake (RDI) of EPA and DHA. The contribution of lean fish to the RDI of EPA and DHA was more limited. The concentrations of all contaminants in fish muscle tissues were lower than the regulatory limits, demonstrating the safety of the environmental conditions of the lake. The contribution to health-based reference values and benefit–risk quotients indicated that the health benefits of consumption of fish from lake Trasimeno outweigh the potential risks.

Incidence of persistent contaminants through blue mussels biomonitoring from Flekkefjord fjord and their relevance to food safety

Dredging activities can lead to the re-suspension of contaminated sediments, resulting in a potential hazard for the whole ecosystem and also for human health. Six-month active biomonitoring was performed in order to monitor the trends of different classes of both legacy (organochlorine - OCPs - and organophosphate (OPs) compounds and polychlorinated biphenyls - PCBs) and emerging (polybromodiphenyl ethers - PBDE - and per- and polyfluoroalkyl substances - PFASs) organohalogen compounds, as well as polycyclic aromatic hydrocarbons (PAHs), in blue mussel (Mytilus edulis spp.) specimens transplanted at different depths in the Flekkefjord fjord. Such biomonitoring was performed to evaluate the efficacy of sediment restoration activities and to check for the potential environmental risk for the biota and food safety for human seafood. Negligible contamination by OCPs, OPs, PBDEs and PFASs was noted in mussels over the 6-month biomonitoring, while a notable increase in the concentrations of PCBs and PAHs occurred in mussels transplanted at 15 m depth in three sampling sites within the fjord, as a consequence of an undersea landslide which occurred during restoration activities. Levels of PCBs and PAHs suggested a potential risk for mussel predators and also for the human health, as they exceeded the limit set by the European Commission for the consumption of bivalve molluscs. These results confirm the reliability of active biomonitoring to flank dredging activities aimed at ecosystem restoration in order to monitor the trend of contaminants and to estimate the potential risk for the aquatic communities and human health.

Health risks and source identification of dietary exposure to indicator polychlorinated biphenyls (PCBs) in Lanzhou, China

Polychlorinated biphenyls (PCBs) are widely present in multiple environmental media even long after the phaseout, posing a health risk to the general population. Dietary intake is the major exposure route of PCBs; however, information is limited regarding PCBs in food that people directly consume. This study aims to measure personal exposure to indicator PCBs, evaluate the health risks, and identify their sources in a typical metropolitan city in China. Multi-day food samples were collected from 21 subjects in Lanzhou, Gansu Province, in two seasons using the duplicate plate method. Samples were extracted and analyzed for seven indicator PCBs using gas chromatography/mass spectrometry. Average daily doses (ADDs) of ∑7PCBs were estimated using Monte Carlo analysis with food intake information. Results show that PCB-118 and PCB-180 were the major congeners in food samples with average concentrations of 1.42 and 1.11 ng/g, respectively. The average (± SD) ADD of ∑7PCBs was 26.47 ± 22.10 ng/kg day among adults aged 18-69 years and displayed small variation across age groups. Comparing with the chronic RfD of 7 ng/kg day, 67% of people had their ADDs exceeding this threshold. The median cancer risk was 5.52 × 10^-5, and 51% of residents had risks exceeding the action level of 10^-4. The principal component analysis identified waste incineration, gasoline engine production, and leakage of #1 PCBs as the major PCBs sources. In conclusion, a large portion of Lanzhou residents has high non-cancer and cancer risks from dietary exposure to PCBs, which warrants control actions targeting these major sources.

Indicator PCBs in farmed and wild fish in Greece - Risk assessment for the Greek population

Health benefits of fish consumption could be counterbalanced by the intake of contaminants after long term fish consumption, burdened even in trace levels. The presence of the indicator PCBs (NDL-PCBs and PCB 118) in farmed and wild seabream and seabass was evaluated. For the determination of PCB, a GC-MS method was developed and evaluated. The association of PCB accumulation in fish with seasonality, locality, production mode and species was also investigated. A new approach for the risk characterisation after exposure to NDL-PCB through fish consumption in Greece was developed, based on the real exposure and the permitted maximum levels of both aggregated dietary exposure and exposure through fish consumption. PCB levels determined in fish were below established permitted limits (6.24 ng/g 95th percentile), while PCB levels and congener distribution varied significantly between farmed and wild fish (p = 0.001). Seasonality was highlighted as an important factor affecting NDL-PCBs accumulation, with high levels coinciding with the reproduction period of each species. Differences were also depicted for sampling sites, with PCB 118 presenting significantly higher values in open seas while NDL-PCB congeners in closed seas. Risk assessment of NDL-PCB intake through fish consumption corrected for the aggregated exposure revealed no risk for the consumers.

A relationship between environmental pollutants and enteric viruses in mussels(Mytilus galloprovincialis)

Mussels can be affected by environmental contaminants, as non-dioxin-like polychlorinated biphenyls (NDL-PCBs), polycyclic aromatic hydrocarbons (PAHs) and cadmium (Cd). Moreover, mussels may concentrate human enteric viruses, like noroviruses (NoVGI/GII), astrovirus (AsV) and rotavirus (RV). Herein, to establish a relationship between environmental and viral contamination, with the aim to ensure human food safety, both chemical and microbiological analysis were carried out in mussels Mytilus galloprovincialis, farmed in Campania region (Italy). Chemical analysis revealed ranges below the European maximum limits, and were: ∑6 NDL-PCBs (28, 52, 101, 138, 153, 180) 0.579-16.857 ng g^-1 wet weight (ww); BaP LOQ (<0.2 µg kg^-1)- 2.9 µg kg^-1 ww, and ∑4 PAHs (BaA, CHR, BbFA, BaP) 0.7-23.7 µg kg^-1 ww; Cd LOQ (<0.005 mg kg^-1)- 0.078 mg kg^-1 ww. In addition, mussels exhibited a prevalence of NoVGI (18%), NoVGII (43%), AsV (40%), RV (30%) and the presence of more than one viruses resulted in about 35%. Overall, a simultaneous contamination, both chemical and viral, was found in 62% of samples. Interestingly, virus-positive mussels showed levels of chemicals higher than negative ones.

Estimation of daily intake of polychlorinated biphenyls not similar to dioxins (NDL-PCB) from fish consumption in Spain in different population groups

OBJECTIVE

To assess the daily intake of polychlorinated biphenyls not similar to dioxins (NDL-PCB) derived from fish consumption in Spain and compare it with tolerance limits in order to establish a safe threshold so that the nutritional benefits derived from fish consumption may be optimized.

DESIGN

Analysis of NDL-PCB in fish samples and ecological study of the estimated intake of NDL-PCB from fish consumption in different Spanish population groups.

SUBJECTS

National representative sample of the Spanish population.

RESULTS

The intake of NDL-PCB was estimated in two different scenarios: upper bound (UB) and lower bound (LB). Estimating intake using the average concentration of NDL-PCB found in the fish samples, the intake for 'other children' is estimated as: 1·80 (UB) and 5·33 (LB) ng/kg per d at the 50th percentile (P50); 7·39 (UB) and 21·94 (LB) ng/kg per d at the 95th percentile (P95) of fish consumption. Estimated NDL-PCB intake shoots up in the toddler group, reaching values of 30·43 (UB) and 90·37 (LB) ng/kg per d at P95. Estimated intake values are lower than those previously estimated in Europe, something expected since in previous studies intake was estimated through total diet. In adults, our estimated values are 1·59 (UB) and 4·72 (LB) ng/kg per d at P50; 4·95 (UB) and 14·72 (LB) ng/kg per d at P95.

CONCLUSIONS

NDL-PCB concentration in fish is under the tolerance limits in most samples. However, daily intake in consumers of large quantities of fish should be monitored and special attention should be given to the youngest age groups due to their special vulnerability and higher exposure.

Polybrominated diphenyl ethers and indicator polychlorinated biphenyls in human milk from China under the Stockholm Convention

Seven congeners of polybrominated diphenyl ethers (PBDEs) (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153,BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) (PCB-28, PCB-52, PCB-101, PCB-138, PCB-153 and PCB-180) were measured in 32 regional pooled human milk samples originating from 1760 volunteering primiparous mothers to evaluate the current human body burden of general population and the temporal trend in China. Individual human milk samples were collected following a WHO-designed procedure. This work is one of parts of the evaluation of effectiveness of Stockholm Convention performance. The concentration of ∑₇PBDEs ranged from 0.3 ng g^-1 lipid to 4.0 ng g^-1 lipid with a mean of 1.5 ng g^-1 lipid. The concentration of ∑₆PCBs ranged from 2.3 ng g^-1 lipid to 19.0 ng g^-1 lipid with a mean of 6.6 ng g^-1 lipid. By comparing with background determination in 2007, there was no significance for ∑₇PBDEs. However, BDE-47, BDE-99, and BDE-100 significantly decreased with an average of 45%, 48%, and 46%, respectively, from 2007 to 2011, and an increase of BDE-183 was founded in most regions. For ∑₆PCBs, there was a significant decline with an average reduction of 41% from 2007 to 2011. These results indicate the effectiveness of reduction and elimination of POPs in China. Future national human milk biomonitoring is worthy to be done to further evaluate the time trend and effectiveness of the Convention performance.

Field investigation to determine the environmental source of PCBs in a pig farm

During a national monitoring plan, a pork fat sample was declared non-compliant for the sum of dioxins and PCB-DL (EU regulation). The National Reference Laboratory together with competent authorities conducted extended investigations to determine rapidly the contamination source at the farm level. A range of samples (n = 129), representative of potential contamination sources, was selected for further characterization (fat, feed, materials, dust, soil) and was analyzed for PCDD/Fs and DL-PCBs by GC-HRMS. A hot spot was localized in the farm, which corresponded to a pre-feed storage tank, the paints of which presented huge DL-PCB concentrations (>1 × 10⁶ pg g^-1), responsible for the contamination. The present case report describes a new source of PCB contamination, previously undescribed.

Lifetime excess cancer risk due to carcinogens in food and beverages: Urban versus rural differences in Canada

OBJECTIVES

To explore differences in urban versus rural lifetime excess risk of cancer from five specific contaminants found in food and beverages.

METHODS

Probable contaminant intake is estimated using Monte Carlo simulations of contaminant concentrations in combination with dietary patterns. Contaminant concentrations for arsenic, benzene, lead, polychlorinated biphenyls (PCBs) and tetrachloroethylene (PERC) were derived from government dietary studies. The dietary patterns of 34 944 Canadians from 10 provinces were available from Health Canada's Canadian Community Health Survey, Cycle 2.2, Nutrition (2004). Associated lifetime excess cancer risk (LECR) was subsequently calculated from the results of the simulations.

RESULTS

In the calculation of LECR from food and beverages for the five selected substances, two (lead and PERC) were shown to have excess risk below 10 per million; whereas for the remaining three (arsenic, benzene and PCBs), it was shown that at least 50% of the population were above 10 per million excess cancers. Arsenic residues, ingested via rice and rice cereal, registered the greatest disparity between urban and rural intake, with LECR per million levels well above 1000 per million at the upper bound. The majority of PCBs ingestion comes from meat, with values slightly higher for urban populations and LECR per million estimates between 50 and 400. Drinking water is the primary contributor of benzene intake in both urban and rural populations, with LECR per million estimates of 35 extra cancers in the top 1% of sampled population.

CONCLUSION

Overall, there are few disparities between urban and rural lifetime excess cancer risk from contaminants found in food and beverages. Estimates could be improved with more complete Canadian dietary intake and concentration data in support of detailed exposure assessments in estimating LECR.

Indicator polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in seafood from Xiamen (China): levels, distributions, and risk assessment

Indicator polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in 289 seafood samples including fishes, crustaceans, and shellfish collected from six administrative regions in Xiamen of China. The residual levels of PCBs, dichlorodiphenyltrichloroethane and its metabolites (DDTs), and hexachlorocyclohexanes (HCHs) ranged <LOD-64 (median 1.8) ng g^-1 wet weight (ww), 0.03-88 (median 1.4) ng g^-1 ww, and <LOD-5.5 (median <LOD) ng g^-1 ww, respectively. The most abundant compounds were PCB101, p,p'-DDT, and β-HCH. Significant differences in the amounts of PCBs and DDTs were recorded among the species, whereas no significant differences were observed among the species with regard to HCH concentrations. Within the regions investigated, the concentrations of PCBs were much lower in Haicang than in other regions and HCHs were detected with highest concentration in Siming, while no significant differences were observed in DDT concentrations. Principal component analysis (PCA) showed that PCB and OCP pollutions came from similar sources in Xiamen. But the pollution sources of Xiangan were diverse. The predominance of PCBs might be attributed to the past usage of domestically produced commercial PCB mixtures, and the profiles of OCPs might indicate their current use in agriculture. Results of carcinogenic risk assessment based on the 50th or 95th percentile exposure levels exceeded the threshold, suggesting that the PCBs should be of concern. On the other hand, the hazard quotients (HQs) of noncancer risks were all far below than 1.

Distribution and residue profile of organochlorine pesticides and polychlorinated biphenyls in sediment and fish of Lake Manzala, Egypt

Sediment and fish (Oreochromis niloticus) samples collected from Lake Manzala were analyzed to assess the spatial distribution of OCPs and 96 PCBs. Relatively higher concentrations of chlorpyrifos, ∑DDT, and HCB were found, particularly at the Bahr Al-Baqar drain station, which has uncontrolled inputs of untreated domestic, agricultural, and industrial wastes. The concentrations of ∑PCBs ranged from 19 to 69 ng/g dw and from 7.4 to 29 ng/g dw for sediment and fish samples, respectively. Ratios of DDT to its metabolites suggest that the source of ∑DDT is from past usage of technical DDT in the regions surrounding the lake. Sediment quality guidelines were exceeded in 88, 75, and 42% of sediments for the Effects Range Low (ERL) for ∑PCBs, ∑DDT, and 4,4'-DDE, respectively. Sediment from the Bahr Al-Baqar drain exceeded the Probable Effects Level (PEL) for DDT isomers 2,4' and 4,4'. All fish samples from Lake Manzala were well below action and tolerance levels set by US EPA for ∑DDT, chlordane, dieldrin, heptachlor, mirex, and PCBs.

HIGHLIGHTS

Distributions of OCPs and PCBs in sediment and tilapia from Lake Manzala were investigated. Chlorpyrifos, ∑DDT, and HCB sediment concentrations were spatially variable and relatively elevated. ∑96PCBs, ∑DDT, and 4,4'-DDE exceeded the Effects Range Low in 88, 75, and 42% of the sediments, respectively. The major input from Cairo, the Bahr Al-Baqar drain, exceeded the Probable Effects Level for DDT isomers in sediments. OCP and PCB concentrations in tilapia were below action and tolerance levels set by the US-EPA.

Roles of Human CYP2A6 and Monkey CYP2A24 and 2A26 Cytochrome P450 Enzymes in the Oxidation of 2,5,2',5'-Tetrachlorobiphenyl

2,5,2',5'-Tetrachlorobiphenyl (TCB) induced type I binding spectra with cytochrome P450 (P450) 2A6 and 2A13, with Ks values of 9.4 and 0.51 µM, respectively. However, CYP2A6 oxidized 2,5,2',5'-TCB to form 4-hydroxylated products at a much higher rate (∼1.0 minute-1) than CYP2A13 (∼0.02 minute-1) based on analysis by liquid chromatography-tandem mass spectrometry. Formation of 4-hydroxy-2,5,2',5'-TCB by CYP2A6 was greater than that of 3-hydroxy-2,5,2',5'-TCB and three other hydroxylated products. Several human P450 enzymes, including CYP1A1, 1A2, 1B1, 2B6, 2D6, 2E1, 2C9, and 3A4, did not show any detectable activities in oxidizing 2,5,2',5'-TCB. Cynomolgus monkey CYP2A24, which shows 95% amino acid identity to human CYP2A6, catalyzed 4-hydroxylation of 2,5,2',5'-TCB at a higher rate (∼0.3 minute-1) than CYP2A26 (93% identity to CYP2A6, ∼0.13 minute-1) and CYP2A23 (94% identity to CYP2A13, ∼0.008 minute-1). None of these human and monkey CYP2A enzymes were catalytically active in oxidizing other TCB congeners, such as 2,4,3',4'-, 3,4,3',4'-, and 3,5,3',5'-TCB. Molecular docking analysis suggested that there are different orientations of interaction of 2,5,2',5'-TCB with the active sites (over the heme) of human and monkey CYP2A enzymes, and that ligand interaction energies (U values) of bound protein-ligand complexes show structural relationships of interaction of TCBs and other ligands with active sites of CYP2A enzymes. Catalytic differences in human and monkey CYP2A enzymes in the oxidation of 2,5,2',5'-TCB are suggested to be due to amino acid changes at substrate recognition sites, i.e., V110L, I209S, I300F, V365M, S369G, and R372H, based on the comparison of primary sequences.

Levels of Polychlorinated Biphenyls in Plastic Resin Pellets from Six Beaches on the Accra-Tema Coastline, Ghana

BACKGROUND

Polychlorinated biphenyls (PCBs) are organic compounds, known to be carcinogenic and banned by the Stockholm Convention. PCBs are hydrophobic substances able to accumulate in organic materials, including plastic pellets. Plastic resin pellets are industrial raw materials that are remolded finished products for industrial and domestic use, commonly used for packaging. Plastic resin pellets were chosen as the medium for monitoring hydrophobic contaminants because they are able to adsorb PCB contaminants. Pellets can be unintentionally washed into the ocean where hydrophobic contaminants such as PCBs are also deposited.

OBJECTIVES

We aimed to identify PCB congeners and quantify PCB pollution levels in the marine environment using resin plastic pellets collected from six beaches along the Accra-Tema coastline in Ghana.

METHODS

Plastic resin pellets (5 g) were extracted with 200 mL of n-hexane for 16 hours by Soxhlet extraction. Concentrations of PCBs from the extracts were determined using gas chromatography with an electron capture detector.

RESULTS

The individual PCB congeners detected were PCB 28, 52, 101, 105, 138, 153, 156 and 180. PCB 28 was detected at all six beaches, with a total concentration of 43.5 ng/g pellet (mean/beach 7.25 +/- 2.47 ng/g pellet; CV = 34%), while PCB 138 was only detected on one beach (Castle Beach) at a total concentration of 0.8 ng/g pellet. The concentration of PCBs ranged from 7.4 ng/g (Sunset Beach) to 47.5 ng/g (Castle Beach) (mean 16.4±15.4 ng/g per beach; CV=94%).

DISCUSSION

PCB concentrations at Castle Beach have been studied previously, showing an increase from 39 ng/g to 47.5 ng/g, whereas levels decreased significantly from 28 ng/g to 14.2 ng/g in Sakumono Beach over the span of three years.

CONCLUSIONS

The concentrations of four detected PCB congeners (28, 52, 101 and 156) were significantly higher than the World Health Organization (WHO) allowable daily intake of 6 ng/g food per day for PCBs. A more efficient industrial and domestic waste disposal system is advocated for Ghana.

Metals and PCB levels in some edible marine organisms from the Ionian Sea: dietary intake evaluation and risk for consumers

Concentrations of some metals (Cd, Cu, As, Hg, Pb) and polychlorinated biphenyls (PCBs) were investigated in edible marine organisms from different trophic levels and feeding behaviour like bivalve molluscs (Mytilus galloprovincialis and Chlamys glabra), gastropod molluscs (Hexaplex trunculus) and some commercial species of fish (Trachurus trachurus, Boops boops, Sarpa salpa and Gobius niger). These species were collected in the first inlet of the Mar Piccolo of Taranto (Ionian Sea, Southern Italy), classified as 'Site of National Interest' established by National Law 426 (1998) and included in the 'National Environmental Remediation and Restoration Projects'. The aim of this work was to investigate contamination levels and public health risks, associated with consuming seafood harvested from these areas. Moreover, in this study, was also estimated the weekly intake in children and adults, both for metals and PCBs. In comparison with the permissible limits set by EC Regulations, Cd and Pb levels were over the limit in the H. trunculus (in all sampling stations) and in the fish T. trachurus respectively. PCBs were over the legal limit in all sampled species with the exception of M. galloprovincialis (station 1), C. glabra and the herbivorous fish S. salpa. In the fish T. trachurus, for example, the concentration of six target PCBs was about five times higher than the EC limit. The estimated intakes of those trace elements included in this study through seafood consumption by the population exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Expert Committee on Food Additives for Cd and Hg in the H. trunculus and T. trachurus, especially in children. Moreover, hazard quotience (HQ) for Hg and Cd was >1 in the children for T. trachurus and H. trunculus consumption. As regard non-dioxin-like PCB (NDL-PCB), the estimated intake were always above the 'provisional guidance value' (70 ng/kg body weight) Arnich et al. (Regul Toxicol Pharm 54: 287-2, 2009) for all sampled organism. Thus, health risks due to the dietary Hg, Cd and PCBs intake, especially for children, cannot be excluded. Therefore, an extended remediation programme is necessary to safeguard marine ecosystem, human health and, not less important, the economic activities, in the Taranto marine area.

PAHs and PCBs accumulated by SPMD-based virtual organisms and feral fish in Three Gorges Reservoir, China

Polycyclic aromatic hydrocarbon (PAHs) and polychlorinated biphenyls (PCBs) accumulated by semipermeable membrane device (SPMD)-based virtual organisms (VOs) and local feral fish were studied in Three Gorges Reservoir (TGR), China. VOs were deployed at seven sites in TGR for two periods in 2009 and 5 species of fish with different living habitats and feeding habits collected in the same periods from two counties in TGR. The concentration and profile of PAHs and PCBs in fish were quite different from those in VOs. Most high-molecular-weight-PAHs were detected in VOs, while they were undetected in fish. Most PCBs were undetected in VOs, while most of them were detected in fish. Low-molecular-weight-PAHs were predominant contaminants of PAHs and non-dioxin-like-PCBs were the main PCBs in fish. The levels of PAHs and PCBs in the few fish samples were low and were not of concern based on chemical contaminant limits of non-carcinogenic effect.

Dietary exposure to non-dioxin-like PCBs of different population groups in Austria

The dietary exposure to the sum of the six indicator PCBs (Σ6 PCBs; PCB 28, 52, 101, 138, 153, and 180) across different Austrian population groups was assessed in this study by combining data on occurrence from food of the Austrian market (n=157) analysed during 2006-2011 with national food consumption data. The most contaminated food group was meat, poultry, game and offal with average levels of ndl-PCBs of 5.20 ng g(-1) fat. In fish and fish products and eggs, mean concentrations of 3.89 ng g(-1) fresh weight (fw) and 4.00 ng g(-1) fat, respectively, were found. In milk and dairy products average concentrations ranged from 3.07 to 4.44 ng g(-1) fat. The mean dietary intake of Σ6 PCBs was estimated to be 3.37 ng kg(-1) bw d(-1) for children (6-15 years old), 3.19 ng kg(-1) bw d(-1) for women (19-65 years) and 2.64 ng kg(-1) bw d(-1) for men (19-65 years). In all three population groups, milk and dairy products was the major contributing food group to the total dietary intake (50-55%) followed by fish and fish products (23-27%). The exposure of all Austrian population groups is well below the tolerable daily intake (TDI) of 10 ng kg(-1) bw d(-1) proposed by WHO, accounting for 34% in children, 32% in women and 26% in men.

Study on polychlorobiphenyl serum levels in French consumers of freshwater fish

INTRODUCTION

Polychlorobiphenyls (PCBs) are persistent pollutants that are widespread in the environment and in foodstuffs, particularly in freshwater fish, which frequently exceed the maximum levels set by European regulations.

OBJECTIVES

First, we describe the consumption of freshwater fish and serum PCB levels in French anglers, a population expected to have the highest level of dietary PCB exposure. Second, we investigated whether there is a statistical relationship between serum PCB levels and the angler consumption of freshwater fish with high PCB bioaccumulation potential (PCB-BP(+) freshwater fish) in order to make recommendations with regard to safe consumption of freshwater fish.

METHODS

We conducted a survey of anglers from six sites with contrasting PCB contamination levels. The survey included a food consumption frequency questionnaire and blood samples were taken to assess serum PCB levels. We used a regression model to determine the main factors contributing to serum PCB levels.

RESULTS

Consumption of PCB-BP(+) freshwater fish was relatively infrequent. Serum PCB levels of the study population and of women of childbearing age were in the same range as those observed in the French population and in neighbouring European countries, but higher than in the North American population. The two factors with the highest positive association with serum PCB levels were age (R(2)=61%) and the consumption of PCB-BP(+) freshwater fish (R(2)=2%). Using the regression model, we calculated, for several scenarios depending on the age and gender of the population, the maximum annual frequencies for PCB-BP(+) freshwater fish consumption that do not exceed the critical body burden threshold.

CONCLUSION

Following the results of this study, the French agency for food, environmental and occupational health and safety (ANSES) issued an opinion and recommended some specific maximum freshwater fish consumption frequencies to protect the French general population.

Polychlorinated biphenyls (PCBs) in air, soil, and cereal crops along the two tributaries of River Chenab, Pakistan: concentrations, distribution, and screening level risk assessment

This study reports the first systematic data on PCB levels and their risk assessments by consumption of cereal food crops from Pakistan. Polychlorinated biphenyls (PCB) including dioxin-like PCBs (dl-PCBs) were analyzed in wheat (n=28), rice (n=28), air (n=6), and soil (n=28) samples to assess the levels, spatial distribution pattern, and their risk assessments along with the two tributaries of River Chenab, Pakistan. ∑33PCB concentrations ranged between 0.15-2.22 ng g(-1)dW, 0.05-9.21 ng g(-1)dW, 0.70-30.5 ng g(-1)dW and 41-299 pg m(-3) in the wheat, rice, soil, and air samples, respectively. In the current study, comparatively lower dioxin toxicity equivalency (TEQ) values were calculated from the previously reported data. Hazardous ratio (HR) for human health risk assessment allied to non-cancer was found lower than integrity.