High Levels Of Polychlorinated Biphenyls Research Articles

Polychlorinated biphenyls (PCBs) in sediments and fish from dredged tributaries and creeks of river Ethiope, South-South, Nigeria: sources, risk assessment and bioaccumulation

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are ubiquitous in nature. In this study, the levels of PCBs were evaluated in sediments and fish samples obtained from dredged tributaries and creeks of River Ethiope. The work also assessed the possible relationship between the parameters and risks posed by polychlorinated biphenyls via several pollution indices. The mean concentrations of \sum PCBs on the sediments spanned from 645 – 3,977 µg/kg (wet season) to 252 – 1,219 µg/kg (dry season) dry weight. The concentrations of PCBs in fishes were 1,688 µg/kg (wet season) and 557 µg/kg (dry season). Higher bioaccumulation factors were observed with lower molecular weight PCBs than the higher ones (9 – Hexa – PCB, 8- Tetra- PCB). The results of the ecological risk (160 \leq Eri < 320), and human health risk (\geq 10-4 to 10-3-\leq 10-6), showed moderately to very high contamination and also moderately to very high cancer risk for children and adults. The strong positive correlation between PCB-114 and PCB-77, PCB-81, PCB-105 (r2 = 1.00, 0.99 & 1.00, p < 0.01) and the risks assessment values which ranged from 6.10 × 10-3 to 1.47 × 10-2 for children and 6.30 × 10-4 to 1.11 × 10-3 for adults (wet season), 1.04 × 10-3 to 2.99 × 10-2 for children and 7.80 × 10-5 to 5.61 × 10-1 for adults (dry season), showed rarely to adversely high potential ecological risk, biological effect and human health risk across the environment. The data show that higher levels of PCBs were observed in sediments and fish samples when compared with available standards. Considering the ILCR, hazard index, toxic equivalent, the sediments and fish obtained from these sites would be considered risky for humans. Dredging activities are majorly responsible for the high levels of PCBs across the sites. These have contributed significantly to the environmental status of the studied area.

Status, distribution, source, and risk of polychlorinated biphenyl levels in soils of five cities from the Hexi Corridor, Northwest China

Few studies have been performed on the persistent organic pollutant contamination in soil from the plateau and remote areas, particularly the mid-latitude arid and semi-arid regions of Northwest China. The occurrence, spatial distribution, source, and potential risk of 12 polychlorinated biphenyls (PCBs) were investigated in soil collected from five Hexi Corridor cities in Northwest China. All of the PCBs were detected individually in the soil samples. The concentration of Σ12PCBs in the Hexi Corridor ranged from 2.0 to 148.5ng/g, with an average of 21.3ng/g. The tetra-CBs and hexa-CBs were the dominant PCB components in the soil. Higher PCB levels were found in the industrial city of Jiuquan, and the fewest PCBs were detected at Jinchang. Source analysis by principal component analysis showed that the dominant sources of PCBs were automobile exhaust, paint additives, insulation materials, and other industrial products. The carcinogenic health risk of PCBs in the Hexi Corridor soil was within acceptable levels, but the exposure risk of PCBs in soil for children was higher than that for adults.

A Review of Polychlorinated Biphenyls (PCBs) Pollution in the Air: Where and How Much Are We Exposed to?

Polychlorinated biphenyls (PCBs) were widely used in industrial and commercial applications, until they were banned in the late 1970s as a result of their significant environmental pollution. PCBs in the environment gained scientific interest because of their persistence and the potential threats they pose to humans. Traditionally, human exposure to PCBs was linked to dietary ingestion. Inhalational exposure to these contaminants is often overlooked. This review discusses the occurrence and distribution of PCBs in environmental matrices and their associated health impacts. Severe PCB contamination levels have been reported in e-waste recycling areas. The occurrence of high PCB levels, notably in urban and industrial areas, might result from extensive PCB use and intensive human activity. Furthermore, PCB contamination in the indoor environment is ten-fold higher than outdoors, which may present expose risk for humans through the inhalation of contaminated air or through the ingestion of dust. In such settings, the inhalation route may contribute significantly to PCB exposure. The data on human health effects due to PCB inhalation are scarce. More epidemiological studies should be performed to investigate the inhalation dose and response mechanism and to evaluate the health risks. Further studies should also evaluate the health impact of prolonged low-concentration PCB exposure.

LEVELS OF INDICATOR POLYCHLORINATED BIPHENYLS IN HUMAN MILK FROM VARNA REGION, BULGARIA

Human milk is an appropriate tool for the assessment of the body burden of humans with lipophilic persistent organic pollutants such as polychlorinated biphenyls (PCBs). Purpose: The aims of the study were to determine the levels of polychlorinated biphenyls in the breast milk of women living in Varna, Bulgaria and to evaluate the association with demographic characteristics. Material and methods: Breast milk samples were collected in 2019 - 2020 from 28 healthy primiparae mothers. The six indicator PCB congeners were determined in individual mother's milk samples by capillary gas chromatography system with mass spectrometry detection (GC-MS). Results: The predominant PCB congener measured in human milk was PCB 153, followed by PCB 138 and PCB 180. The lower chlorinated congeners PCBs (28, 52 and 101) were found below the limit of detection in most individual samples. The median level of the Indicator PCBs in milk samples was 29.1 ng/g lipid weight. The highest PCBs levels were found in breast milk from primiparae mothers 36 – 40 age (36.8 ng/g lipid as a sum of six Indicator PCBs), suggesting bioaccumulation of these pollutants. Conclusions: Positive association was found between the Indicator PCBs levels and the age of mothers. The levels of the Indicator PCBs in breast milk were found to be lower than levels reported in other studies in the European countries.

Silicone wristbands as personal passive samplers of exposure to polychlorinated biphenyls in contaminated buildings.

Polychlorinated biphenyls (PCBs) were used in a number of industrial products from 1950 to 80s, including building materials. As a result, some buildings exhibit high levels of PCBs in the indoor environment. The aim of this study was to test silicone wristbands as a method for estimating personal exposure to PCBs in buildings both in controlled experiments and field settings. In the controlled study, the sampling kinetics of silicone wristbands were investigated in a 31-day uptake study. The field study focused on the application of wristbands as a personal exposure measure. It included 71 persons in a contaminated housing estate and 23 persons in a reference group. The linear uptake of PCBs ranged from 2 to 24days for PCB-8, 18, 28, 31, 40, 44, 49, 52, 66, 99, and 101 under controlled conditions. A generic sampling rate (Rk) of 2.3m3 d-1 corresponding to a mass transfer coefficient of 17mh-1 was found in the controlled kinetic study. Partitioning coefficients were also determined for the nine congeners. In the field study, an apparent generic field sampling rate (Rf) of 2.6m3 d-1 was found; when adjusted to reported hours exposed, it increased to 3.5m3 d-1. The wristbands were shown to be a good tool for predicting airborne exposure, as there was a highly significant difference between the exposed and reference group as well as a clear trend when used for ranking of exposure. In correlation analyses, highly significant correlations were observed between air and wristband levels, though adjusting by self-reported exposure time only increased the correlation marginally in the field study. The obtained kinetic data can be used for estimating the magnitude of external exposure. The advantages provided by the wristbands in the form of easy use and handling are significant, though the limitations should also be acknowledged.

Mixture of environmental pollutants in breast milk from a Spanish cohort of nursing mothers.

Breastfeeding is one of the most effective ways to ensure child health and survival, with several benefits for both the infants and their mothers. However, breast milk can contain environmental pollutants with endocrine disruption capacity, neurotoxicity and/or potential to alter microbiota. Monitoring breast milk provides information on the current chemical exposure of breastfed infants and, in addition, on the current and historical exposure of nursing mothers. In this study, the levels of a wide range of pollutants were measured in breast milk of Spanish nursing mothers. Target chemicals were dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), oxy-chlordane, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), per- and poly-fluoroalkyl substances (PFASs) (including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)), chlorpyrifos, bisphenol A (BPA), tetrabromobisphenol A (TBBPA), and a number of toxic and essential elements. Traces of most chemicals were found. A correlation between the levels of some persistent organic pollutants (POPs) and maternal characteristics (age and body mass index) was observed, while smoking was associated to higher concentrations of some toxic elements. Higher levels of PCBs were detected in samples from Spanish primiparous mothers compared to non-Spanish multiparous women. Breast milk from low-income mothers showed higher content of DDT and DDE than high-income mothers. Although breastfeeding is clearly beneficial for babies, the exposure to this mixture of hazardous substances, as well as their interaction and combined effects must not be disregarded.

Occurrences and possible sources of persistent organic pollutants (POPs) in ice-free area soils in East Antarctica

Antarctica is widely regarded as a sink for persistent organic pollutants (POPs). However, there is a scarcity of data on the occurrence and spatial pattern of POPs in Antarctica, especially in the cold-xeric East Antarctica. Here, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in soils from the Larsemann Hills, the second-largest ice-free area along East Antarctica, were investigated. It is shown that the main OCP contaminants were HCB, p,p’-DDD and δ-HCH (3.7–1522.3 pg g−1, 38.2–2276.6 pg g−1 and < LOD–570 pg g−1, respectively). OCPs in soils were primarily caused by long-distance atmospheric transport, but local sources can be found in areas heavily impacted by local human activities. Among DDTs and HCHs, only p,p’-DDD and δ-HCH were detected, indicating that DDTs and HCHs have aged. For PCBs (14.1–993.4 pg g−1), low-chlorinated PCB congeners were found in soil samples far from the station areas (Zhongshan, Progress II, and Progress I), possibly due to long-range atmospheric transport, while high levels of high-chlorinated PCB were found in the soils inside the station area (Law Base) and close to the main road, possibly associated with local station activities. Among the measured PBDEs (81.8–695.5 pg g−1), BDE-209 was the most frequently observed species, and the low-BDE found in soil samples could be from BDE-209 photodegradation. The majority of samples containing high concentrations of BDE-209 are concentrated in the station areas, implying that its source may be related to local station activities.

Distribution of organochlorine pesticides and polychlorinated biphenyls present in surface sediments of the Sabaki and Tana estuaries, Kenya

Polychlorinated biphenyls (PCBs) and Organochlorine pesticides (OCPs) in the surface sediments of the Sabaki and Tana estuaries were studied to determine distribution as well as their ecological risk. The concentration range of PCBs and OCPs were 0.65-9.29 ng/g dw and 0.47-9.84 ng/g dw, respectively. Sabaki Bridge in the Sabaki River and Tana 4 in the Tana River recorded high levels of both PCBs and OCPs. The calculated values of DDD+DDE/ DDT showed that the presence of DDT from both the rivers is a result of historical input. The ecotoxicological impact of sediment pollution by PCBs and OCPs was assessed using sediment quality guidelines specified by the Canadian Council of Ministers of the Environment. The concentration values for PCB, HCB, Heptachlor epoxide, and Chlordane in this study indicate low ecological risk to sediment dwelling organisms. DDT showed an adverse biological effect to sediment dwelling organisms. As a result, there is a need to establish a programme for monitoring persistent organic pollutants in Kenya, so that any elevation in concentration above the environmental quality standards can be detected and appropriate actions taken to minimize potential adverse effects to the environment and public health.

Dietary Acid Load, Serum Polychlorinated Biphenyl Levels, and Mortality Following Breast Cancer in the Long Island Breast Cancer Study Project.

Dietary acid load (DAL) may be associated with all-cause mortality (ACM) and breast cancer-specific mortality (BCM), and these associations may be modified by serum polychlorinated biphenyl (PCB) levels. Participants included 519 women diagnosed with first primary in situ or invasive breast cancer in 1996/1997 with available lipid-corrected PCB data. After a median of 17 years, there were 217 deaths (73 BCM). Potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores calculated from a baseline food frequency questionnaire estimated DAL. Cox regression estimated covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between PRAL and NEAP with mortality. We evaluated effect measure modification by total serum PCB levels (>median vs. ≤median). PRAL quartile 4 versus quartile 1 was associated with an ACM HR of 1.31 (95%CI = 0.90–1.92). In the upper median of PCBs, ACM HRs were 1.43 (95%CI = 0.96–2.11) and 1.40 (95%CI = 0.94–2.07) for PRAL and NEAP upper medians, respectively. In the lower median of PCBs, the upper median of NEAP was inversely associated with BCM (HR = 0.40, 95%CI = 0.19–0.85). DAL may be associated with increased risk of all-cause mortality following breast cancer among women with high total serum PCB levels, but inversely associated with breast cancer mortality among women with low PCB levels.

Polychlorinated biphenyls and organochlorine pesticides in breast milk samples and their correlation with dietary and reproductive factors in lactating mothers in Istanbul.

Persistent organic pollutants (POPs) continue to threaten the environment and human health. We have investigated levels of polychlorinated biphenyls (PCBs) and organochlorinated pesticides (OCPs) in breast milk samples. A questionnaire was also obtained from the study participants. A total of 48 healthy lactating mothers (mean age: 29.5±0.8 years) living in Istanbul volunteered to participate in this study. High-resolution analyses of several OCPs and PCB congeners were done by gas chromatography. The levels of seven major PCB congeners (28, 52, 101, 118, 138, 153, and 180) and eight OCPs (α-benzenehexachloride, β-benzenehexachloride, δ-benzenehexachloride, hexachlorobenzene (HCB), and 2,4'-dichlorodiphenyldichloroethylene (2,4DDE), 4,4'-dichlorodiphenyldichloroethylene (4,4DDE), 2,4'-dichlorodiphenyltrichloroethane (2,4DDT), and 4,4'-dichlorodiphenyltrichloroethane (4,4DDT)) were determined. The analysis showed that the highest levels of PCBs were observed in PCB 52 (22.99±8.78 ng/g lipid), PCB 101 (12.22±7.8 ng/g lipid), PCB 28 (11.44±5.16 ng/g lipid), and PCB 153 (1.70±0.74 ng/g lipid). The highest OCPs detected were 4,4DDT (3.33±2.05 ng/g lipid) and 4,4DDE (0.86 ± 0.39 ng/g lipid), and the lowest was observed in HCB (0.016 ± 0.01 ng/g lipid). Our findings show that traces of PCBs and OCPs are still present in breast milk of lactating women living in Istanbul, and these pollutants decline in multipara women compared to primipara mothers. We also suggest that breast milk is a useful and representative biological tool for human biomonitoring of POPs.

Exploring associations between prenatal exposure to multiple endocrine disruptors and birth weight with exposure continuum mapping

BackgroundImproved understanding of how prenatal exposure to environmental mixtures influences birth weight or other adverse outcomes is essential in protecting child health. ObjectiveWe illustrate a novel exposure continuum mapping (ECM) framework that combines the self-organizing map (SOM) algorithm with generalized additive modeling (GAM) in order to integrate spatially-correlated learning into the study mixtures of environmental chemicals. We demonstrate our method using biomarker data on chemical mixtures collected from a diverse mother-child cohort. MethodsWe obtained biomarker concentrations for 16 prevalent endocrine disrupting chemicals (EDCs) collected in the first-trimester from a large, ethnically/racially diverse cohort of healthy pregnant women (n = 604) during 2009–2012. This included 4 organochlorine pesticides (OCPs), 4 polybrominated diphenyl ethers (PBDEs), 4 polychlorinated biphenyls (PCBs), and 4 perfluoroalkyl substances (PFAS). We applied a two-stage exposure continuum mapping (ECM) approach to investigate the combined impact of the EDCs on birth weight. First, we analyzed our EDC data with SOM in order to reduce the dimensionality of our exposure matrix into a two-dimensional grid (i.e., map) where nodes depict the types of EDC mixture profiles observed within our data. We define this map as the ‘exposure continuum map’, as the gridded surface reflects a continuous sequence of exposure profiles where adjacent nodes are composed of similar mixtures and profiles at more distal nodes are more distinct. Lastly, we used GAM to estimate a joint-dose response based on the coordinates of our ECM in order to capture the relationship between participant location on the ECM and infant birth weight after adjusting for maternal age, race/ethnicity, pre-pregnancy body mass index (BMI), education, serum cotinine, total plasma lipids, and infant sex. Single chemical regression models were applied to facilitate comparison. ResultsWe found that an ECM with 36 mixture profiles retained 70% of the total variation in the exposure data. Frequency analysis showed that the most common profiles included relatively low concentrations for most EDCs (~10%) and that profiles with relatively higher concentrations (for single or multiple EDCs) tended to be rarer (~1%) but more distinct. Estimation of a joint-dose response function revealed that lower birth weights mapped to locations where profile compositions were dominated by relatively high PBDEs and select OCPs. Higher birth weights mapped to locations where profiles consisted of higher PCBs. These findings agreed well with results from single chemical models. ConclusionsFindings from our study revealed a wide range of prenatal exposure scenarios and found that combinations exhibiting higher levels of PBDEs were associated with lower birth weight and combinations with higher levels of PCBs and PFAS were associated with increased birth weight. Our ECM approach provides a promising framework for supporting studies of other exposure mixtures.

The Association of the Polychlorinated Biphenyl Class of Endocrine Disruptors With Polycystic Ovary Syndrome and Thyroid Dysfunction

Introduction:. Polychlorinated biphenyls (PCBs) are a class of endocrine disruptors with a long half-life in the body that are associated with irregular menses, growth and development delay, increased cancer risk, thyroid disorders and an increased risk of diabetes. Higher levels of PCBs have been related to polycystic ovary syndrome (PCOS). PCB toxicity depends on their structure, with coplanar PCBs being most toxic (akin to dioxins); therefore, PCB subtypes were determined to see if they differed in women with PCOS compared to normal controls. Methods:. PCB levels were compared in Caucasian women with (n=29) and without (n=30) PCOS and related to metabolic features. PCBs were fractionated then analysed by high-resolution gas chromatography-unit resolution mass spectrometry. Results:. The control and PCOS groups were age and BMI matched (p=ns); insulin resistance was not different (HOMA 1.7±1.0 v 2±1.6, p=ns) but free androgen index was increased in PCOS (p<0.004). PCB-118, 138, 153 and 180 were found in all subjects, whilst fewer subjects showed PCB-28(15/59), PCB-52(4/59) or PCB-101(26/59). There was no difference for PCB-188,138,153 and 180 between controls and PCOS, but all correlated with increasing age (p<0.01) and decreasing estimated glomerular filtration rate (p<0.05); no correlations with BMI, HOMA, testosterone, TSH or T3 were found; however, PCB-118 (the only coplanar PCB detected) associated with an increased T4/T3 ratio (p<0.01). Conclusion. Despite PCBs being banned over a decade ago, PCBs were detected, but did not differ between age and BMI matched women with and without PCOS. Thyroid dysfunction may be only associated with toxic coplanar PCBs, such as PCB-118 that was associated with a higher T4/T3 ratio.

Metabolic activation and toxicological evaluation of polychlorinated biphenyls in Drosophila melanogaster

Degradation of polychlorinated biphenyls (PCBs) is initiated by cytochrome P450 (CYP) enzymes and includes PCB oxidation to OH-metabolites, which often display a higher toxicity than their parental compounds. In search of an animal model reflecting PCB metabolism and toxicity, we tested Drosophila melanogaster, a well-known model system for genetics and human disease. Feeding Drosophila with lower chlorinated (LC) PCB congeners 28, 52 or 101 resulted in the detection of a human-like pattern of respective OH-metabolites in fly lysates. Feeding flies high PCB 28 concentrations caused lethality. Thus we silenced selected CYPs via RNA interference and analyzed the effect on PCB 28-derived metabolite formation by assaying 3-OH-2′,4,4′-trichlorobiphenyl (3-OHCB 28) and 3′-OH-4′,4,6′-trichlorobiphenyl (3′-OHCB 28) in fly lysates. We identified several drosophila CYPs (dCYPs) whose knockdown reduced PCB 28-derived OH-metabolites and suppressed PCB 28 induced lethality including dCYP1A2. Following in vitro analysis using a liver-like CYP-cocktail, containing human orthologues of dCYP1A2, we confirm human CYP1A2 as a PCB 28 metabolizing enzyme. PCB 28-induced mortality in flies was accompanied by locomotor impairment, a common phenotype of neurodegenerative disorders. Along this line, we show PCB 28-initiated caspase activation in differentiated fly neurons. This suggested the loss of neurons through apoptosis. Our findings in flies are congruent with observation in human exposed to high PCB levels. In plasma samples of PCB exposed humans, levels of the neurofilament light chain increase after LC-PCB exposure, indicating neuronal damage. In summary our findings demonstrate parallels between Drosophila and the human systems with respect to CYP mediated metabolism and PCB mediated neurotoxicity.

Validation of proximity-based estimates of residential exposure to emissions of dioxins and dioxin-like compounds in the U.S.

Background: Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are persistent organic pollutants emitted from industrial sources. The relationship between proximity to emissions from these sources and personal exposure is poorly understood.Methods: We linked geocoded residential addresses and serum measurements of PCDDs, PCDFs, PCBs, and their derived TEQ (toxic equivalency quotient) for 5,725 participants in the 1999-2004 U.S. National Health and Nutritional Examination Survey (NHANES) to a U.S. Environmental Protection Agency database of 4,478 historical emission sources of dioxins and dioxin-like compounds (e.g., coal-fired power plants, solid waste incinerators). We calculated continuous and categorical (3, 5, 10km) exposure metrics reflecting distance to the nearest facility and estimated intensity of exposure with a distance- and toxicity-weighted average emissions index (AEI [ng TEQ/km2]). We used linear regression models to evaluate associations between proximity metrics and log-transformed sums of serum PCDDs, PCDFs, PCBs, and TEQ and used logistic regression to determine the extent these metrics predicted high (top quartile) serum levels.Results: Overall, 16%, 30%, and 53% of participants lived within 3, 5, or 10km of one or more facility, respectively. No consistent associations were observed between serum levels and simple proximity metrics reflecting distance to nearest facility. Mean serum concentrations of total PCDDs/PCDFs/PCBs and total TEQ were highest among participants in the top AEI5k quartile; an increasing trend was statistically significant only for PCBs (p&lt;0.01). In adjusted models, participants in the highest AEI5k quartile had increased odds of having high levels of total PCBs (OR=1.8; 95%CI:1.3-2.5) and TEQ (OR=1.6; 95%CI:1.0-2.5) compared to those with no facilities within 5km.Conclusion: In this nationally representative population, we demonstrated that residential proximity to emissions was positively associated with serum total PCBs and TEQ. Findings from this effort support the use of distance- and emissions-based exposure proxies to estimate personal exposure.

Exposure to environmental contaminants and risk of pregnancy induced hypertension and gestational diabetes mellitus

Introduction: Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB), are ubiquitously found in the environment and resistant to degradation. POPs, along with persistent organochlorine pesticides including p,p'-dichlorodiphenyl dichloroethylene (DDE) and heavy metals have been associated with various pregnancy outcomes but results are inconsistent.Objective: We assessed the associations between prenatal exposures to organochlorines and heavy metals and the development of gestational diabetes mellitus (GDM) and pregnancy induced hypertension (PIH). Methods: We used existing exposure models to predict prenatal levels of PCBs (using the sum of 4 prevalent congeners), DDE, HCB, lead (Pb) and mercury (Hg) for all pregnant women living in southeast Massachusetts between 1993-1998 (n=10,270). Outcome and covariate data were obtained from Massachusetts birth records. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for GDM and PIH were estimated using multivariable logistic regression models. Results: Approximately 1.8% of women in this study population developed GDM and 1.9% of women developed PIH. PCBs, DDE and HCB were strongly associated with the development of GDM, while no associations were observed for Pb and Hg exposure. After adjusting for weight gain during pregnancy, smoking during pregnancy, parity, race, and socioeconomic factors, the effects of PCBs (OR: 1.56; 95% CI: 1.10-2.22) and DDE (OR: 2.84; 95% CI: 1.90-4.25) on GDM remained. However, the risk associated with HCB exposure was no longer significant after adjusting for confounders. Associations with PIH were null.Conclusions: These results suggest that women with high prenatal levels of PCBs and DDE may have a higher risk of developing GDM. We found no associations between PIH and exposures to organochlorines and heavy metals.

Polychlorinated biphenyls and organochlorine pesticides in water and sediment from Volturno River, Southern Italy: occurrence, distribution and risk assessment

BackgroundTo assess the Volturno River pollution and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) caused by Polychlorinated biphenyls (PCBs) and Organochlorine pesticides (OCPs), 32 PCBs and aldrin, α-BHC, β-BHC, δ-BHC, γ-BHC (lindane), 4,4′- DDD, 4,4′-DDE, 4,4′-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulphate, endrin, heptachlor, heptachlor epoxide (isomer B) and methoxychlor have been selected and were analyzed in three different phases: dissolved phase (DP), suspended particulate matter (SPM) and sediments. PCBs and OCPs were extracted using an SPE column for the DP and glass fiber filter for SPM and sediment samples. Cleaned extracts were analyzed by gas chromatography with electron capture detector (ECD) and mass spectrometry (MS) detector for PCBs and OCPs, respectively.ResultsPollutants discharges of PCBs and OCPs into the sea were calculated in about 106.9 kg year−1 (87.1 kg year−1 of PCBs and 19.7 kg year−1 of OCPs), showing that this river could be a major source of PCBs and OCPs pollution to the Central Mediterranean Sea. Total concentrations of PCBs ranged from 4.1 to 48.0 ng L−1 in water (sum of DP and SPM) and from 4.3 to 64.3 ng g−1 in sediment samples. The concentrations of total organochlorine pesticides (OCPs) obtained in water (sum of DP and SPM) ranged from 0.93 to 8.66 ng L−1 and from 0.52 to 9.89 ng g−1 in sediment samples. Principal component analysis shows that all PCB compounds are more likely to come from surface runoff than an atmospheric deposition.ConclusionThe data show that higher levels of PCBs and OCPs were found in sediment samples than in DP and SPM samples, which are an indication of no fresh inputs of these compounds. Based on our results, unintentionally produced PCBs by industrial processes (and other processes) were considered to be the main sources of PCBs in Volturno River and Estuary sediments. Considering the Sediment Quality Guidelines (SQGs), the Ecological Risk Index (ERI), the Risk Quotient (RQ) and the USEPA Environmental Quality Standards (EQS), the Volturno River and its Estuary would be considered an area in which the integrity is possibly at risk.

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.

High levels of dioxins and PCBs in meat, fat and livers of free ranging pigs, goats, sheep and cows from the island of Curaçao

Samples of adipose tissue, meat and livers from pigs, cows, sheep and goats from Curaçao were analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and dioxin-like (dl-) and non-dioxin-like (ndl-) PCBs (polychlorinated biphenyls). Levels in many samples of adipose tissue were higher than the EU maximum levels (MLs) for PCDD/Fs and the sum of PCDD/Fs and dl-PCBs (sum-TEQ), indicating unusually high levels. Median sum-TEQ (Toxic Equivalents) levels for pigs, cows, sheep and goats were 0.9 (range 0.3–35), 3.0 (0.5–14), 5.7 (0.3–28) and 6.5 (0.5–134) pg TEQ g−1 fat. For most samples, the congener pattern pointed to the burning of waste as the major source, in line with the fact that most animals forage outside. MLs for ndl-PCBs were also exceeded in some of the samples, indicating that some areas are additionally contaminated with PCBs. Meat levels showed similar lipid based levels as adipose tissue, contrary to liver levels, which were much higher in most animals. Pigs showed liver sequestration at lower levels in adipose tissue than the ruminants. The relatively high levels observed in this study are likely to result in high exposure of consumers and measures were taken to reduce the contamination of areas where animals forage.

Changes in thyroid hormone related proteins and gene expression induced by polychlorinated biphenyls and halogen flame retardants exposure of children in a Chinese e-waste recycling area

Polychlorinated biphenyls (PCBs) and halogen flame retardants (HFRs) are major pollutants in e-waste recycling area. High internal exposure levels of PCBs and HFRs are harmful to human thyroid hormone (TH) equilibrium. To examine their disrupting effects on TH, we conducted a study on children (n = 114) of an e-waste recycling and a control area in South China. Concentrations of PCBs, HFRs, and TH levels were determined in serum samples. TH related proteins and their corresponding gene were also monitored as markers of such disruption. Levels of these chemicals in the exposed group were much greater than those in the control group. Results of the linear regression and generalized additive model indicated the presence of close relationships between the internal exposure levels and the responses of TH related proteins, gene expression. More extensive exposure concentrations of these chemicals led to higher expression of iodothyronine deiodinase I and decreased the concentrations of thyroid-stimulating hormone, expression of TH receptor α, indicating the exertion of discrepant and even contrary influences on equilibrium of TH, and a compensation of these mechanisms may kept the homeostasis of TH. These results for children warrant further investigation on the health risks of PCBs and HFRs exposure in e-waste area.

Хлорорганические соединения в камбалах рода Hippoglossoides Gottsche, 1835 из дальневосточных морей России

Хлорорганические пестициды (ХОП) и полихлорированные бифенилы (ПХБ) относятся к группе стойких органических загрязняющих веществ (СОЗ) и являются глобальными суперэкотоксикантами. Рыба и морепродукты — важный источник полноценного белка и полиненасыщенных жирных кислот, особенно для жителей приморских районов. До 90 % всех поллютантов поступают в организм человека с пищей. Конечным депо СОЗ в окружающей среде являются морские экосистемы, а следовательно, эти вещества могут накапливаться в различных объектах морского промысла. В работе представлены сведения о концентрациях ХОП [изомеры ГХЦГ (α-, β-, γ-), ДДТ и его метаболиты (ДДД и ДДЕ)] и ПХБ в мышцах камбал рода Hippoglossoides Gottsche, 1835, обитающих в дальневосточных морях России (Охотское море, Татарский пролив, Японское море). Липиды экстрагировали из гомогенатов тканей рыб смесью гексана и ацетона с последующим разрушением жировых компонентов концентрированной серной кислотой. ХОП и ПХБ разделяли при помощи колоночной хроматографии полярным и неполярным растворителями. Ксенобиотики количественно определяли методом газовой хромато-масс-спектрометрии. Для оценки качества выбранной методики применяли метод стандартных добавок. Средняя воспроизводимость концентраций аналитов варьировала от 94,6 до 103,7 %, что говорит о надёжности полученных данных и об эффективности использованных методов. Средние концентрации ∑ДДТ, ∑ГХЦГ, ∑ХОП (∑ДДТ + ∑ГХЦГ) и ∑ПХБ конгенеров составили: в образцах, отобранных в восточной части Охотского моря, — (62 ± 89), (50 ± 52), (100 ± 125) и (92 ± 45) нг·г−1 липидов; в южной части Охотского моря — (20 ± 17), (36 ± 37), (54 ± 41) и (99 ± 43) нг·г−1 липидов; в Японском море — (40 ± 29), (62 ± 36), (102 ± 50) и (1616 ± 1177) нг·г−1 липидов соответственно. В образцах из Татарского пролива средние уровни ∑ГХЦГ, ∑ХОП и ∑ПХБ составили (221 ± 182), (224 ± 180) и (455 ± 317) нг·г−1 липидов соответственно. ДДТ обнаружен в трёх исследованных образцах. В восточной части Охотского моря в камбалах зарегистрированы наибольшие концентрации ДДТ и умеренные — ГХЦГ, что может быть связано с расположением на полуострове Камчатка «могильника» ядохимикатов и пестицидов, в котором захоронены ХОП. Поступление ПХБ в воды южной части Охотского моря может объясняться как активным судоходством, так и наличием стоков с мусорных полигонов, несущих остаточные количества ПХБ в экосистему. Южная часть Охотского моря — самый чистый из исследованных районов, характеризующийся наименьшим содержанием ДДТ, ГХЦГ и ПХБ в организмах. В камбалах из залива Невельского (Татарский пролив) ДДТ практически отсутствовал. В то же время в них выявлен самый высокий уровень содержания ГХЦГ, представленного только β-изомером, что говорит о длительной циркуляции токсиканта в экосистеме. Согласно постановлению Правительства Сахалинской области, на территории о-ва Сахалин есть полигоны размещения пришедших в негодность или запрещённых пестицидов, хранение которых (на момент вступления постановления в силу) осуществлялось с нарушениями, способными привести к серьёзному загрязнению окружающей среды. Скорее всего, источником загрязнения Татарского пролива стали именно они. Другим источником загрязнения ГХЦГ могут быть течения, выносящие воды Японского моря через пролив Невельского в Охотское море. Высокие уровни ПХБ в водах залива могут быть связаны с активным судоходством и, возможно, с влиянием свалок бытовых отходов на о-ве Сахалин. Камбалы из Японского моря характеризуются наибольшим загрязнением СОЗ. Поступление ХОП в акваторию моря может быть связано с поверхностными смывами, речными стоками, утечками из хранилищ запрещённых к применению пестицидов и атмосферным переносом из стран Азии, где до сих пор разрешено применение некоторых ХОП. Найденные уровни ПХБ на порядок величин превышают таковые в камбалах из Охотского моря и Татарского пролива, что может быть объяснено активным судоходством в водах Японского моря, влиянием действующих нефтеналивного и угольного портов в г. Находке, а также местным загрязнением прибрежной полосы (так называемых диких пляжей). Таким образом, исследована аккумуляция хлорорганических пестицидов (ГХЦГ и ДДТ) и полихлорированных бифенилов в мышцах камбал из дальневосточных морей России. При существующем глобальном фоне СОЗ, сформировавшемся на планете, уровни этих соединений в камбалах южной части Охотского моря могут быть приняты как фоновые. Наибольшему антропогенному прессу подвержено Японское море, где концентрации ПХБ значительно превышают таковые как в дальневосточных морях России, так и в сравниваемых регионах мира в целом.