PCBs Congeners Research Articles

Persistent Organic Pollutants (POPs) in three bathyal chondrichthyes from the North-Western Mediterranean Sea

The deep-sea can act as a sink for legacy contaminants such as organochlorines (OCs), causing damages in its inhabitants for their persistence and their prolonged effects in the organisms. HCB, DDT and its isomers, and 28 PCBs congeners were detected in muscle and embryonic tissues of three deep-sea chondrichthyes Chimaera monstrosa (n = 16), Dalatias licha (n = 12) and Etmopterus spinax (n = 51) sampled in Ligurian and Tyrrhenian Sea (Mediterranean Sea). Contaminant distribution in E. spinax and C. monstrosa was PCBs > DDTs ≫ HCB while in D. licha was DDTs > PCBs ≫ HCB. Statistically significant differences were highlighted in OC levels among the species, but no such differences were found among sexes. Ratios between DDT isomers highlighted an historical input of the pesticide in the environment. For the first time was also demonstrated maternal transfer in deep water chondrichthyes, specifically in E. spinax where was highlighted that transfer of contaminants increases with increasing compound's Log Kow.

Investigation of polychlorinated biphenyls in breast milk from two regions in Bulgaria.

Human breast milk is an optimally balanced infant food and a suitable tool for assessing the burden of humans with lipophilic persistent organic pollutants. The aim of this study was to investigate the accumulation profile of polychlorinated biphenyls in breast milk of women living in Bulgaria and to assess the health risk to infants. Breast milk samples were obtained from 72 healthy primiparae and multiparae mothers, living in two regions in northeastern Bulgaria - Varna region and Dobrich region, in the period October 2019-July 2021. Important information for the study, such as age, body mass, smoking and dietary habits, was collected through a questionnaire. Fifteen congeners of PCBs, including six indicator congeners, were determined by capillary gas chromatography system with mass spectrometry detection. The lipid content of the tested samples was in the range from 0.5% to 6.7%, with average value 3.25%. The six indicator PCBs in human milk samples formed up to 89% of the total PCBs levels. The most abundant congener was PCB 153, followed by PCB 138 and PCB 180. Five of the 15 PCB congeners (77, 126, 128, 156, 169) were not detected in any of the milk samples. The arithmetic mean PCB levels in milk samples from Varna (32.7ng/g lw) were found higher than PCB levels in breast milk of mothers from Dobrich (22.5ng/g lw). The highest PCB levels were found in milk samples from primiparae mothers in 36-40 age group (for both regions). Infant exposure to PCBs present in human milk was estimated using toxic equivalents (TEQ). The health risk to infants was assessed and was compared to the tolerable daily intake (TDI). Positive correlation was found between the arithmetic mean PCBs levels and two important factors - the age and body mass index of the primiparae group. The mean values of the analyzed PCB congeners in breast milk samples from multiparae were lower than in those from primiparae mothers. The regional differences in PCB concentrations were small, suggesting similar exposures in the studied regions. The levels of PCBs in breast milk were found lower than levels from studies in other European countries. Statistical data does not show any association between PCB levels in milk and dietary habits. The results showed that infants are not at risk of any adverse effects caused by PCBs through breast milk.

A comparative monitoring of maternal and cord serum polychlorinated biphenyls levels from Iranian pregnant women between industrial and urban areas

The aim of this study was to compare maternal and fetal exposure to PCBs in pregnant women from a petrochemical and gas area (PGA) and an urban area (UA), by the analyses of serum samples from mother (MS) and cord (CS). After liquid-liquid extracting, samples were analyzed for 12 PCBs congeners by gas chromatography mass spectrometer. Adjusted multiple linear regression models showed the mean levels (μg/L) of total PCBs in the MS and CS samples from the PGA (1.70 ± 0.81 and 1.19 ± 0.43) were significantly higher than those from UA (1.64 ± 0.75 and 1.07 ± 0.38). PCB 44 was predominant in both MS and CS serum samples, and in both PGA (0.80 ± 0.70 and 0.76 ± 0.67) and UA (0.79 ± 0.39 and 0.67 ± 0.34). A negative correlation was found for PCB 52 as one-unit increase in the cord serum levels was associated with 0.024 g decrease in newborn weight. Similarly, one-unit increase in the maternal serum PCB 18 concentrations were associated with 0.09 and 0.086 cm decrease in newborn height and head circumference. The serum levels of PCB 18 and 52 in the mothers who consumed meat and milk at least 1 meal/week were higher than these who consumed meat and milk never or less than 1 meal/month. The findings in this study indicated that higher maternal exposure to PCBs, as result of living in an industrialized area, leads to higher PCBs accumulation in cord blood, which consequently passes to the developing fetus. These events may cause harmful effects on both them in-utero and afterbirth growth and development.

Dioxin-like polychlorinated biphenyl (pcbs) congeners induce inflammatory responses and reduce thyroid-specific genes expression in human thyrocytes via ahr pathways

Dioxin-like polychlorinated biphenyl (pcbs) congeners induce inflammatory responses and reduce thyroid-specific genes expression in human thyrocytes via ahr pathways

Detection of indicator polychlorinated biphenyls (I-PCBs) and polycyclic aromatic hydrocarbons (PAHs) in cow milk from selected areas of Dhaka, Bangladesh and potential human health risks assessment

In this study, the levels of indicator PCBs congeners and PAHs compounds were reported in cow milk from selected areas in Dhaka, Bangladesh, and the potential human health risks were assessed. A total of 100 milk samples were collected and analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). Method validation was performed using recovery performance, linearity, limit of detection (LOD), and limit of quantification (LOQ) assays. PCBs congeners, including PCB No. 52 (2,2´,5,5´-tetrachlorobiphenyl), PCB No. 101 (2,2´,4,5,5´-pentachlorobiphenyl), PCB No. 153 (2,2,4,4,5,5–hexachlorobiphenyl), and PCB No 209 (Decachloro-1,1′-biphenyl perchlorobiphenyl) were detected, whereas PCB No 28 (2,2 ´,4–trichlorobiphenyl), PCB No. 138 (2,2´,3,4,4´,5´–hexachlorobiphenyl), and PCB No 180 (2,2´,3,4,4´,5,5´–heptachlorobiphenyl) were not detected in the analyzed milk samples. Among the 16 PAHs compounds, benzo (a) anthracene and chrysene were detected in milk samples. The Σ hazard risk index (HI) of all detected PCBs congeners was below the limit set by the European Food Safety Authority, which indicates limited health risks to animals and humans in the study area. However, the presence of PCBs and PAHs in milk samples from industrial areas may negatively affect human health, and further detailed studies are required to ensure public health safety.

Potential health risk assessment of HFRs, PCBs, and OCPs in the Yellow River basin.

The concentrations of PBDEs, NBFRs, DP, PCBs, and OCPs were analyzed in water samples of the Yellow River Basin (YRB) and in soil and maize samples collected from basin irrigation areas to understand the status of POPs and associated health risks. The results showed: (1) the congeners of eight PBDEs and seven NBFRs were detected in 10 tributaries, with average concentrations of 1575 and 4288pg. L-1. Thirty-three congeners of PCBs were detected, and the average concentration of PCB was 232pg. L-1. Five HCHs were the primary congeners among twenty-three congeners of OCPs in the ten tributaries, accounting for 79% of the total. The average concentration of OCPs was 8287pg. L-1. (2) Similar congeners of HFRs, PCBs, and OCPs were found in the trunk water. The ranking based on the HFR concentration was upstream>downstream>midstream, and that of the PCB and OCP concentration was downstream>upstream>midstream. (3) PCBs and OCPs in the trunk water of the YRB and in the soil and maize irrigated with river water pose potential carcinogenic and non-carcinogenic risks. The results indicate considerable organic pollution in the YRB, suggesting that national emission standards for POPs should be implemented soon.

A perspective on the potential health risks from PCBs and heavy metals contamination of <i>M. merluccius</i> from Mediterranean Sea

In this study, we determined the concentration of six marker PCBS congeners and four trace elements, all having a maximum tolerable level of intake set by EU regulation, in samples of European hake taken from the Mediterranean Sea. The results showed that the contaminant levels were below the recommended international limits in all samples, although with higher PCBs concentrations in samples from Ligurian and Adriatic Sea. The relationships between the contaminants and the sampling sites were investigated using analysis of variance (ANOVA) and Tukey's HSD post-hoc tests. Statistical analysis revealed significant interactions especially between the PCBs, the sum of PCBs and the sites. To evaluate the potential health risk from consumption, we calculated the estimated daily intake (EDI) for adults, finding that total health risk index (HRI) value was low (< 1) in the case of chronic consumptions, despite the non-negligible mercury concentration.

A perspective on the potential health risks from PCBs and heavy metals contamination of M. merluccius from Mediterranean Sea.

In this study, we determined the concentration of six marker PCBS congeners and four trace elements, all having a maximum tolerable level of intake set by EU regulation, in samples of European hake taken from the Mediterranean Sea. The results showed that the contaminant levels were below the recommended international limits in all samples, although with higher PCBs concentrations in samples from Ligurian and Adriatic Sea. The relationships between the contaminants and the sampling sites were investigated using analysis of variance (ANOVA) and Tukey's HSD post-hoc tests. Statistical analysis revealed significant interactions especially between the PCBs, the sum of PCBs and the sites. To evaluate the potential health risk from consumption, we calculated the estimated daily intake (EDI) for adults, finding that total health risk index (HRI) value was low (< 1) in the case of chronic consumptions, despite the non-negligible mercury concentration.

Concentrations, Possible Sources and Influence Factors of Dissolved Polychlorinated Biphenyls in the Water of Yangzhuang Coal Mining Subsidence Area, China

To understand the content, composition and other pollution states of dissolved PCBs in the waters of coal mining subsidence area, the research object is determined as the water of Yangzhuang mining subsidence area. Seven point locations are selected there and three layers of water samples are collected in each of the point locations so as to detect and analyze PCBs with GC-MS and make sources recognition and analysis of relative factors. Results show that other PCB congeners all have been detected except PCB138 congener among the 14 detected PCBs congeners. PCBs mainly consist of trichlorodiphenyl and pentachlorodiphenyl. These two substances in each site occupy 59 to 79% of total PCBs. The pollution sources are primarily two sorts: the atmospheric transmission source and the unintended source. PCBs content has a moderate linear positive correlation with DOC and water temperature and a moderate linear negative correlation with DO. PCBs concentration is in a lower-middle level.

Risk assessment of some organic contaminants: a case study based on food consumption in Tanta and Ismailia cities, Egypt

The impact of some organic pollutants on some residents of Tanta and Ismailia cities of Egypt through their consumption of vegetables, fruits and fish (Nile tilapia and catfish) was examined. Residues of organochlorine (OCS) and organophosphorus (OPS) as some polychlorinated biphenyls (PCBS) were compared with pesticides as well maximum residue limits (MRLS). Probable health risk to consumers was also assessed. P, P'-DDT, P, P'-DDE, P, P'-DDD, endrin, α-BHC, (lindane), and hexachlorbenzene (HCB) were the most detected organochlorine compounds, but did not exceed MRLs.However, OPS residues were the most frequently detected contaminants. PCBs congeners 28, 70, 52, and 180 were detected in tilapia fish from Tanta, but congeners 28 and 180 were the only detected congeners in samples collected from Ismailia region. ∑PCBS values in all matrices did not exceed MRLS. Hazard index (HI) exhibited unity for all compounds at 50 the decreasing order: catfish > vegetables > fruits > Nile tilapia in Tanta, while in Ismailia the order was Nile tilapia > fruit > vegetables. Results also revealed that risk values for adults were greater than those of children categories.

Examining Changes in Persistent Organochlorine Pollutants Following High Consumption of Farmed Atlantic Salmon: Results from an 8-Week Dietary Intervention Study

Background: In 2004 a publication in Science by Hites et al. reported a 10 to 100-fold higher concentrations of persistent organochlorine pollutants (POPs) in farmed Atlantic salmon compared to wild Pacific salmon. These findings generated intense debate on the health-risk-benefits of farmed Atlantic Salmon.Objective: To examine the short-term effect of high consumption of farmed Atlantic salmon on serum POP concentrations.Methods: A 4-arm randomized controlled trial in overweight or obese subjects (BMI: 27.5-32.5 kg/m2) assigned to energy-restricted seafood diet over an 8-week period (SEAFOOD-plus, 2004-2005, n&amp;#61;324). Controls were assigned to a fish free diet and one arm was assigned to three meals per week of farmed Atlantic salmon (24 meals), matched for energy. Of these participants 20 male cases (Salmon) and 20 male controls were selected who experienced modest weight loss and concentrations of pp-DDE, HCB and PCBs (congeners no. 118, 138, 153, 170, 180) were measured at baseline and endpoint.Results: Median baseline concentrations for sum of PCBs, pp-DDE and HCB were 1.41, 0.78 and 0.16 ng/mL, respectively. Mean weight loss at endpoint was 4.8kg and 4.5kg in the salmon and control group (p&amp;#61;0.68), respectively. Concentrations of EPA and DHA were significantly increased at endpoint by ~32% in the Salmon group but reduced by ~14% in controls, suggesting compliance to the intervention. At endpoint the mean sum of PCBs was increased by 0.36ng/mL in the salmon group (p&amp;#61;0.22). Lack of significance is unlikely to be explained by weight loss during the intervention as only a minor change of -0.06ng/mL (p&amp;#61;0.84) in PCB concentrations were observed among controls. Individual PCB congeners, pp-DDE and HCB were non-significantly but systematically increased by 6 to 41% of mean levels in the salmon group compared to controls.Conclusion: Our study suggests that high consumption of farmed Atlantic Salmon over a short period does not substantially affect circulating POP levels.

Comparative study of persistent organic pollutant (POP) (chlorinated pesticides, PCBs, and dioxins/furans) concentrations in cancer-affected human organs with those of healthy organs

The concentrations of POPs (persistent organic pollutants) including 16 compounds of OCPs, 12 dioxin-like PCBs congeners, and 17 PCDDs/Fs congeners were determined in 46 human adipose tissue samples gathered from Jordanian citizens. Thirteen adipose tissue samples of healthy people were collected from Jordan University Hospital and 33 adipose tissue samples of cancer-affected patients were collected from King Hussein Cancer Center. All samples were extracted, cleaned-up, and analyzed using GC/MS. In the healthy person's samples, among the OCP compounds, the highest concentration was found for heptachlor-oxo-epoxide (5696.71μg/kg), while among the PCB congeners, the non-ortho PCB 126 shows the highest TEQ concentrations (5554.5μgTEQ/kg) and among the PCDDs/Fs congeners, the highest TEQ value was found for the congener 2,3,4,7,8-PeCDFs (5.93μgTEQ/kg). For the cancer-affected patient's samples, the highest concentration among the OCP compounds was found for o,p-DDT (638.7μg/kg), while among the PCBs congeners, the highest TEQ value was found for the non-ortho-PCB 126 (3366.24μgTEQ/kg) and among the PCDDs/Fs congeners, the highest TEQ value was found for the congener 1,2,3,7,8-PeCDDs (20.64μgTEQ/kg). OCP concentration level in adipose tissue samples for healthy people was 32 times higher than for cancer patient persons, while the TEQ values for dioxin-like PCB concentrations in adipose tissue samples of healthy people was 2.2 times higher than in the samples of cancer-affected patient and the TEQ values for PCDDs/Fs in adipose tissue samples of cancer-affected patient was 3 times higher than in the samples of healthy people.

First report of bioaccumulation and bioconcentration of aliphatic hydrocarbons (AHs) and persistent organic pollutants (PAHs, PCBs and PCNs) and their effects on alcyonacea and scleractinian corals and their endosymbiotic algae from the Persian Gulf, Iran: Inter and intra-species differences

The coral reefs of the Persian Gulf are the most diverse systems of life in the marine environment of the Middle East. Unfortunately, they are highly threatened by local and global stressors, particularly oil pollutants. This is the first quantitative and qualitative study aimed at assessing the concentration and sources of n-alkanes and POPs (PAHs, PCBs and PCNs) in coral tissues, symbiotic algae (zooxanthellae), reef sediments and seawaters in coral reefs of Lark and Kharg in the Persian Gulf, Iran. This work was conducted on eight species of six genera and three families of hard corals and one family of soft coral. A significant variation in the concentration of ∑30n-alkanes and POPs (∑40PAHs, ∑22PCBs and 20PCNs) was found in the decreasing order: zooxanthellae > coral tissue > skeleton > reef sediment > seawater. The bioaccumulation of these compounds was 2-times higher in ahermatypic than in hermatypic corals, among which significant variations were observed in both sites. In Kharg, Porites lutea had the highest mean concentration of ∑30n-alkanes and ∑40PAHs in soft tissue, whereas the lowest values were in Platygyra daedalea. A contrasting trend was documented for ∑22PCBs and 20PCNs, with the highest level reported in soft tissue of P. daedalea and the lowest in P. lutea at Kharg. Compositional pattern of AHs and PAHs demonstrated the predominance of LMW-PAHs and n-alkanes. In skeleton and reef sediments, tetra, penta and tri-CBs were the most abundant PCBs congeners followed by di-CB > hexa-CB > hepta-CB > octa-CB,whiletri-CB > di-CB > tetra-CB > penta-CB > hexa-CB > hepta-CB > octa-CB was observed for soft tissue, zooxanthellae and seawater. The results of RAD test indicated significantly negative correlation between total concentration of these compounds with zooxanthellae density, the chlorophyll-a and C2 in corals at both reefs. This is the first report on levels, health assessment and source apportionments of POPs in zooxanthellae and a first step in the implementation of specific coral reef management measures.

Spatial and temporal distribution of pesticides and PCBs in the atmosphere using XAD-resin based passive samplers: A case study in the Quequén Grande River watershed, Argentina

XAD-resin based passive air samplers were deployed at 10 sites in the Quequén Grande River watershed in Argentina during three periods to evaluate the spatial and temporal variations of pesticides and PCBs in the atmosphere. Endosulfan and chlorpyrifos were the most prevalent pesticide because of their continued usage in Argentina, while DDTs, HCHs, chlordanes, dieldrin and heptachlors registered lower levels, reflecting their use in the past. Atmospheric endosulfan levels were 1–2 orders of magnitude higher during the application period (application: 800–12,000 pg/m3, pre- and post-application: <2–350 pg/m3), suggesting that its use in the area continued even after a ban came into effect. The remaining organochlorine pesticides also reached higher concentrations during this period, which is more likely attributable to temperature controlled air-surface exchange than current applications. The highest concentrations of chlorpyrifos were recorded during the application period, in particular at agricultural sites, where its use is wide-spread on soybean fields. The fungicide chlorothalonil was found predominantly at urban sites and in proximity to Quequén harbor, suggesting that its use might be domestic and as a biocide in antifouling paints. A different temporal pattern was observed for the herbicide trifluralin, suggesting its use in the early stages of the wheat-growing season during winter. Limited spatial variations in PCBs levels indicate a diffuse contamination source in the study area, while their relatively high correlation with temperature suggests re-volatilization from local sources. Relative enrichment of lighter PCBs congeners could be attributed to re-evaporation from secondary sources as well as atmospheric transport from urban sites.

Cathodic photoelectrochemical detection of PCB101 in environmental samples with high sensitivity and selectivity

A novel cathodic photoelectrochemical (PEC) sensing method was developed for fast and convenient detection of PCB101 taking advantages of the excellent PEC reducibility of Pd quantum dots (QDs) modified molecularly imprinted TiO2 nanorods (NRs). Attributed to the efficient PEC reduction of PCB101 on the cathode surface, sensitive cathodic photocurrent would be produced with increasing PCB101 concentration under a negative bias potential, giving a low PCB101 detection limit of 5×10−14molL−1. Meanwhile, molecular imprinting (MI) technique was integrated by in situ introduction of MI sites on the surface of TiO2 NRs, so that highly specific adsorption and reduction of PCB101 congener could be obtained. The results indicated that the PEC sensor presented excellent selectivity toward PCB101 with the coexistance of 100-fold excess of other pollutants including the PCBs congeners, other aromatic pollutants, and heavy metal ions. The cathodic PEC sensor was sucessfully applied in determination of PCB101 in real water and soil samples, and the results had good consistency with that obtained by the traditional GC–MS. This work provides a new concept and research basis for fabricating cathodic PEC sensor for the environmental pollutants with specific structures that were easily reduced.

Contribution of Persistent Organic Pollutant Exposure to the Adipose Tissue Oxidative Microenvironment in an Adult Cohort: A Multipollutant Approach.

Despite growing in vitro and in vivo evidence of the putative role of persistent organic pollutants (POPs) in the induction of oxidative damage in cell structures, this issue has been poorly addressed from an epidemiologic perspective. The aim of this study was to explore associations between adipose tissue POP concentrations and the in situ oxidative microenvironment. A cross-sectional study was conducted in a subsample (n = 271) of a previously established cohort, quantifying levels of eight POPs and four groups of oxidative stress biomarkers in adipose tissue. Associations were explored using multivariate linear regression analyses adjusted for potential confounders. We assessed the combined effect of POPs on oxidative stress/glutathione system biomarkers using weighted quantile sum regression (WQS). Increased concentrations of p,p'-DDE, HCB, β-HCH, dicofol, and PCBs (congeners -138, -153, and -180) were predominantly associated with higher lipid peroxidation (TBARS) [exp(β) = 1.09-1.78, p < 0.01-0.04)] and SOD activity [exp(β) = 1.13-1.48, p < 0.01-0.05)] levels. However, only a few associations were observed with glutathione system biomarkers, e.g., PCB-180 with total glutathione [exp(β) = 1.98, p = 0.03]. The WQS index was found to be positively associated with SOD activity, and PCB-138, PCB-180, and β-HCH were the main contributors to the index. Likewise, the WQS index was positively associated with TBARS levels, with the three PCBs acting as the main contributors. This is the first epidemiological evidence of the putative disruption by POPs of the adipose tissue oxidative microenvironment. Our results indicate that POP exposure may enhance alternative pathways to the glutathione detoxification route, which might result in tissue damage. Further research is warranted to fully elucidate the potential health implications.

Endocrine disrupting chemicals and ovulation: Is there a relationship?

Although the potential for endocrine disrupting chemicals (EDCs) to disrupt female fecundity is great, few studies have assessed the threat to human reproduction. This study investigates levels of organochlorines in relation to their impact on women’s menstrual cycles and ovulatory status.To address concerns of the Akwesasne Mohawk community in upstate New York regarding well-established exposure to EDCs, women’s fertility and reproductive health endpoints, we recruited 215 women between the ages of 21 and 38 years to measure menstrual cycle characteristics and levels of local pollutants. Of these, 155 women collected saliva over the course of their menstrual cycle allowing for analysis of estradiol and progesterone levels and the determination of ovulatory status in relationship to their serum pollutant levels. A subset of participants (15) who did not commence cycling within a month of their enrollment were not included in the analysis, hence reducing the sample size to 140 participants. Additionally, a lipid panel, estradiol and progesterone were assessed in serum on Day 3 of the menstrual cycle.Median cycle length for women in the sample was 29 days. After aligning the cycles, 110 women were considered ovulatory and 45 (29%) anovulatory. Concentrations of groups of more persistent PCBs congeners, HCB, and p,p’-DDE did not differ significantly with ovulatory status. However, a sub-group of low-chlorinated PCB congeners, considered to be estrogenic were significantly higher among anovulatory women. These findings suggest that certain EDC’s, ubiquitous in our environment, may adversely affect menstrual cycles and thus have the capacity to impair reproductive function, including likelihood of conception.

DFT Studies of SN2 Dechlorination of Polychlorinated Biphenyls.

Nucleophilic dechlorination of all 209 PCBs congeners by ethylene glycol anion has been studied theoretically at the DFT level. The obtained Gibbs free energies of activation are in the range 7-22 kcal/mol. The reaction Gibbs free energies indicate that all reactions are virtually irreversible. Due to geometric constrains these reactions undergo rather untypical attack with attacking oxygen atom being nearly perpendicular to the attacked C-Cl bond. The most prone to substitution are chlorine atoms that occupy ortho- (2, 2', 6, 6') positions. These results provide extensive information on the PEG/KOH dependent PCBs degradation. They can also be used in further developments of reaction class transition state theory (RC-TST) for description of complex reactive systems encountered for example in combustion processes.

Distribution of persistent organic pollutants (PAHs, Me-PAHs, PCBs) in dissolved, particulate and sedimentary phases in freshwater systems

The occurrence of three groups of hazardous organic contaminants (PCBs, PAHs, Me-PAHs) in fifteen watercourses and rivers located in highly urbanized and industrialized zones was studied. The distribution of 62 organic contaminants was determined in three matrices: in the dissolved phase, associated with suspended solid matter (SSM) and in sediment. Their distributions in the aquatic environment depend strongly on their physicochemical properties. Low molecular weight PAHs were predominant in the dissolved phase while those with high molecular weight accumulated preferentially in SSM and sediments. Among the 28 PCBs congeners, only PCB153 was detected. The results showed that the contamination of these areas originated mainly from combustion processes. The three the most polluted sites identified are surrounded by big cities. Ecotoxicological assessment based on the international Sediment Quality Guidelines (SQGs) showed that the toxic effects of the sediment in these watercourses and rivers occurred due to high levels of hydrocarbons.

Franciscana dolphins as PCBs marine biomonitors in Argentina, south-west Atlantic Ocean

Including a multi-year collection of samples (2004–2011) the present research fills 20 years of an information gap regarding the PCB burden in south-west Atlantic franciscana dolphins (Pontoporia blainvillei) while aiming to test the null hypothesis that PCBs congeners are increasingly bioaccumulating in south-west Atlantic specimens in relation to northern hemisphere records. In addition, the present survey analyses indicators of potential biological impairment associated to PCBs tissue burden. The results could associate each sampling area group of dolphins to one or two Aroclor® patterns and point to dominant regional diffuse sources entering PCBs mixtures to the marine environment with a possible regional/long-range atmospheric contribution. In addition, total PCB levels were from four to seven times lower than the closer precedents for the area (18–26 years ago) indicating a progress in the environmental release and biota exposure of PCBs and posing an objective indicator of success of the present international elimination programme. Further, when compared with regional and global bioaccumulation patterns, PCBs congeners in Argentinean specimens appeared to occur in a decreasing tendency. Finally, calculated TEQs TCDD levels raised a concern in regards to environmental safety, showing guideline values to be widely exceeded and the occasional occurrence of positive correlations between PCBs bioaccumulationvs. sexual immaturity.