Average Polychlorinated Biphenyls Concentrations Research Articles

Investigation of organic contaminants in the blubber of a blue whale (Balaenoptera musculus) first stranded on the coast of Taiwan.

This study presents a comprehensive assessment of persistent organic pollutants (POPs) in the blubber of a stranded blue whale found on the coast of Taiwan. The analysis included polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), Hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The whale exhibited evident signs of emaciation, including low body weight, reduced blubber fat content, and thin blubber thickness. The dominant fatty acid type detected in the blubber was short-chain monounsaturated fatty acids (SC-MUFA), known to aid in thermoregulation. Stable isotope ratios indicated that the blue whale occupied a lower trophic position compared to a fin whale, suggesting its proximity to krill habitats in the Southern Ocean for feeding. The average concentrations of DDTs (1089.2 ± 4.7ng/g lw; ΣDDT) and PCBs (1057.1 ± 49.8ng/g lw) in the blubber were almost one order of magnitude higher than PAHs (41.7 ± 10.0ng/g lw), HCB (70.6 ± 2. ng/g lw), and PBDEs (7.2 ± 1.2ng/g lw). Pollutant concentrations in this individual blue whale were comparable to levels found in Norway, higher than those found in Chile, and notably lower than those found in Canada and Mexico. Calculating the biomagnification factor (BMF) for the POPs from krill (Euphausia superba) to the blue whale revealed significant bioaccumulation of pollutants in this particular whale. Additional research is imperative to achieve a thorough comprehension of bioaccumulation of POPs and their potential toxicological impacts on whale health.

DETERMINATION OF POLYCHLORINATED BIPHENYLS (PCBs) IN SURFACE WATER IN ONDO STATE NIGERIA

Polychlorinated biphenyl compounds (PCBs) were included to the Stockholm Convention's list of typical persistent organic pollutants on May 22, 2001. (POPs). Humans have produced PCBs, which are pervasive in the environment. They are a concern for people all around the world because of their toxic, bioaccumulative, long-lasting, hydrophobic, and transboundary characteristics. The study's goals included describing how PCBs are distributed in surface water and evaluating how certain physiochemical factors affect PCB concentrations. Five separate Okitipupa locations—OAUSTECH, Igodan, Okunmo, Idepe, and Lebi/Ofe River—had their water samples taken. The overall average concentration of PCBs discovered in the samples taken from five (5) distinct places was determined to be as follows: OAUSTECH (5.720.13), Igodan (5.520.00), Okunmo (3.480.03), Idepe (21.830.02), and Lebi/Ofe (0.160.00), with their combined probability being determined to be 0.001. Twenty-five (25) PCB congeners were examined using a gas chromatography-electron capture detector (GC-ECD). The majority of congeners were below the detection threshold at every site. Total PCB values varied from 0.16 g/L to 21.83 g/L. The correlation between the overall level of polychlorinated biphenyls and the total organic carbon was positive (0.214), but it was weak (PCBs) and pH, positive (0.096) but poor correlation between the electrical conductivity, and a positive (0.220). The levels found in this investigation, with the exception of one area, were obviously lower than the 0.5μg/l level advised by the WHO. The water's concentration of polychlorinated biphenyls (PCBs) is not significantly impacted by the physicochemical characteristics, and the water is safe to use for household purposes.

The concentrations and sources of PAHs and PCBs in soil from an oil field and estuary in the Yellow River Delta, China

The occurrence of organic pollutants [i.e. polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs)] had been assessed in the soil samples collected from two sub-regions (an oil field and the Yellow River Estuary) in the Yellow River Delta (YRD), China. The concentrations of PAHs and PCBs in the soil were in the range of 157.8–481.7 μg kg−1 (dry weight) and 5.6–56.6 μg kg−1 (dry weight), respectively. The average concentration of PAHs in the soil samples from the oil field were 274.0 μg kg−1, and that in the estuary soil samples were 244.4 μg kg−1. The average concentration of PCBs in the soil samples from the oil field and the estuary were 24.2 μg kg−1 and 10.8 μg kg−1, respectively. The contribution of low molecular weight PAHs (two-ring and three-ring PAHs) was larger in the soil samples from the oil field than that in the estuary soil samples. Both PAHs and PCBs contaminations in the estuary area were lower than that in the oil field area. By using diagnostic ratios analysis, the main source of PAHs was attributed to petroleum input caused by the fuel oil or light refined petroleum products in the Gudong Oilfield. The amount of low-chlorine congeners (three to four chlorine atoms) PCBs in soil samples from the oil field were higher than that in the estuary soil samples. The congeners analysis of PCBs and the correlation analysis between the concentrations of PAHs and PCBs were employed. The results indicated that the emission of PCBs in YRD were influenced by both Gudong oilfield and other industrial sources.

Activity-based exposure levels and lifetime cancer risk for workers exposed to polychlorinated biphenyls during electronic waste dismantling in Buriram province, Thailand

The activity-based exposure concentrations of airborne polychlorinated biphenyls (PCBs) for electronic waste (e-waste) dismantling workers in Buriram province were examined, and their possible carcinogenic risk was assessed. The average exposure concentration of total PCBs in the particle (PM2.5–10 and PM2.5) and gas phases were 53.51 ± 23.68, 65.41 ± 23.06, and 82.72 ± 78.61 ng/m3, respectively, and were all significantly (p < 0.05) higher for workers exposed during burning wires than those of the dismantling bulky-, small-, and internal e-waste parts. The dominant PCB congeners mainly found during e-waste dismantling were the low-chlorinated group, including PCB-28, -52, −77, −81, −105, −118, and −126. PCB-28 and -77 were observed as predominant co-congeners derived from mechanical dismantling, whereas PCB-52, -118, and −126 were the main species emitted from burning activities. The workers exposed to PCBs from burning wires were estimated to have the highest lifetime cancer risk of 1.64E-05, about 2.5- to 3.3-fold higher than those who dismantled bulky-, small- and internal e-waste parts. Consequently, workers should be recommended to wear high-efficiency respiratory protection masks to avoid direct exposure to PCBs and to reduce their possible carcinogenic risk.

The importance of oxbow lakes in the floodplain storage of pollutants

Abstract Oxbow lakes are important stores for fine-grained sediment, which potentially makes them critical sinks for sediment-associated pollutants. We leverage an exhaustive public archive of coring data, supplemented by our data collection, to provide a quantitative assessment of the role of oxbows as off-channel sinks. We investigated loading trends of sediment-sorbed polychlorinated biphenyls (PCBs) within oxbows of the Housatonic River, an actively meandering river in western Massachusetts, USA. Our results reveal the efficiency of oxbows as sinks, with average PCB concentrations (14.8 ppm) that are nearly twice that of the surrounding floodplain (7.56 ppm). Even though the 5.83 km2 floodplain is the largest sink of PCB-laden material, storing as much as 14.1 t of PCBs or 2.42 g m−2, oxbows store more than 20% of all PCBs (3.63 t of PCBs or 11.2 g m−2) while making up just over 5% of the floodplain surface area. Nearly 85% of the oxbow storage of PCBs occurs within the first 50 m of floodplain, making clear the significance of regular oxbow production to the off-channel storage of sediment-associated pollutants.

Regional-temporal Trends and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Olive Lands in Bursa, Turkey

ABSTRACT In this study, it was aimed to determine the spatial and temporal variations of polychlorinated biphenyl (PCB) levels in olive lands (0–5 cm) and to identify dominant PCB homologous groups and cancer risk values. In this context, surface soil samples were taken from seven olive lands in Bursa-Turkey for 9 months. Sampling points were categorized as rural, semi-rural, residential, and industrial areas. Regional-temporal trends of 43 PCB compounds were reported. The total average (∑43) PCB concentrations ranged between 8.3 ± 3.31 ng/g DM and 15.4 ± 3.3 ng/g DM. The lowest ∑43 PCB concentration was measured at the rural area (Mudanya Yörükali-MY) and the highest value was measured at Orhangazi Asilzade (OA), which is an industrial area. The dominant homologous group in all seasons was found to be 5-CBs (31%) followed by 4-CBs (16%) and 6-CBs (15%). Cancer risks were calculated and risk trend was determined as ingestion > dermal > inhalation. The values ranged between 5.26 × 10−6 and 1.28x10−5, 2.62 × 10−5 and 1.08x10−5, 1.68 × 10−1 and 6.9 × 10−12 for dermal, ingestion and inhalation, respectively. Also, the correlation between the levels of certain soil characteristics (dry matter, pH, and temperature) was also investigated. Statistical results showed that for PCB#89/101, PCB#135/144, PCB#126, PCB#156/171/202, PCB#172 PCB#170/190 it was determined that there was a significant relationship.

Investigating the spatial distribution of polychlorinated biphenyls in sediment in the Pearl River Delta, South China.

One hundred forty-three surface sediment (0-5 cm depth) samples were collected from locations representing industrialized areas, less-industrialized areas, and e-waste recycling areas in the Pearl River Delta (PRD). The spatial distribution of polychlorinated biphenyls (PCBs) and their potential adverse effects on aquatic organisms were investigated. The average PCB concentration in the less-industrialized areas (background) in the PRD was approximately 10 ng/g dry weight (dw), which was generally half that found in the industrialized areas (approximately 22 ng/g dw). Severe PCB contamination, with concentrations ranging from 1000 to 26500 ng/g dw, was found in pond sediments collected from e-waste recycling areas. It is very likely that such contamination would have had adverse effects on the aquatic biota there. PCBs in the e-waste recycling areas were dominated by penta- and hex-PCB congeners, which made them significantly different from those found in other regions, where tri- and tetra-PCB congeners were predominant. Higher abundances of less chlorinated congeners were seen in the less-industrialized areas compared to the industrialized areas. Differences in the transport abilities of different congeners, together with dechlorination of higher chlorinated congeners, is the most likely reasons for this.

Polychlorinated Biphenyl Emissions from Steelmaking Electric Arc Furnaces.

Electric arc furnaces (EAFs) in steelmaking plants are a major source of dioxins. Preheating of steelmaking raw materials is widely used in EAFs to reduce energy consumption. Few studies have investigated emissions of dioxin-like polychlorinated biphenyls (PCBs) from EAFs, and the PCB emission levels and characteristics during preheating are unknown. In this study, PCB concentrations and distributions in stack gases emitted during EAF preheating were determined. The average dioxin-like PCB concentrations in stack gases emitted during preheating of three EAFs were 1236.1, 81,664.4, and 669.8pg/Nm3, respectively. These values were greatly influenced by the composition of the steelmaking raw materials. The PCB profiles in all samples were dominated by less-chlorinated homologs. PCB emission factor for preheating in the EAFs is 0.58µg WHO-TEQ/ton averagely, indicating significant emissions of PCBs from preheating process. The data will be useful for developing approaches for preventing and controlling PCB emissions from EAFs.

Distribution and Chiral Signatures of Polychlorinated Biphenyls (PCBs) in Soils and Vegetables around an e-Waste Recycling Site.

The distribution and composition of polychlorinated biphenyls (PCBs) within soil-plant systems around a notorious e-waste recycling site were investigated. The average total PCB concentrations in rhizospheric soils (RSs) and nonrhizospheric soils (NRSs) were 2160 and 1270 pg g-1 dry weight (DW), respectively. PCBs were more enriched in RS than NRS for most vegetable species. PCB accumulation in plant tissues varied greatly among plant cultivars, ranging from 4020 to 14 500 pg g-1 DW in shoots and from 471 to 24 400 pg g-1 DW in roots. The compositions of PCBs in soil and plants showed that hexa- and hepta-chlorinated PCBs were preferentially accumulated in soils, while tri- and tetra-PCBs were abundant in plant tissues. These results indicated that low-chlorinated PCBs might be prone to accumulation and transfer within plants, which was confirmed by the relationship between the root concentration factor and octanol-water coefficient. The first eluting enantiomers of PCB 84 and PCB 95 were preferentially transferred between the soil and plants, while the stereoselectivity of PCB 136 varied among plant species. A significant difference in enantiomeric fractionation of PCB 84 between the soil and roots indicated that enantiomeric enhancement of PCB 84 occurred during its translocation from soil to root, whereas no such difference was observed in these chiral PCBs during their translocation from the root to the shoot.

Residual characteristics and potential health risk assessment of polychlorinated biphenyls (PCBs) in seafood and surface sediments from Xiangshan Bay, China (2011–2016)

Xiangshan Bay provides most of the seafood for residents from the southeast coast of China. However, information on the safety of local seafood was not well known. In this study, we investigated the residue, spatial distribution and potential health risks of ten polychlorinated biphenyls (PCBs) in seafood and surface sediment samples during six years (2011–2016). The results indicated the level of PCBs in 9 types of seafood from Xiangshan Bay ranged between ND and 25.3 ng·g−1. The highest average concentration of PCBs (14.2 ng·g−1) was observed in Ostreidae. The average PCB concentrations in the surface sediments was 1.58 ng·g−1 (ND to 15.2 ng·g−1). The biota-sediment accumulation factors of the PCBs in most seafood indicated that the seafood was readily subjected to the bioaccumulation of PCBs from sediments. The carcinogenic risks were all within the safe ranges of 9 types of seafood for adults.

Urban geochemistry and potential human health risks in the Metropolitan Area of Buenos Aires: PAHs and PCBs in soil, street dust, and bulk deposition.

Soil, street dust, and bulk deposition (dry and wet deposition) were collected in the Metropolitan Area of Buenos Aires (MABA), Argentina, to assess the polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) pollution and the potential risks to human health. Compared with other countries, the mean concentration of PAHs and PCBs in surface soils, street dust and bulk deposition of MABA were at a low or moderate level. Average PAHs and PCBs concentrations in bulk deposition (5.7 ± 5.1 and 0.41 ± 0.25µgg-1, respectively) were five and ten times higher than those of soil (1.08 ± 0.98 and 0.02 ± 0.01µgg-1) and street dust (1.2 ± 0.95 and 0.04 ± 0.03µgg-1), respectively. Different compositional profiles, observed in the three matrices for both groups of contaminants, could be attributed to dissimilar source contribution, partition processes between gas and particulate phases, and transformation. The most contaminated bulk deposition presented higher values for cancer and non-cancer risks relative to soil and street dust. In all matrices, non-carcinogenic risks were below the safety threshold (HI < 1). Regarding carcinogenic risks, exposure to both bulk deposition and soil indicated a moderated potential for cancerous development (Incremental lifetime cancer risk ~ 3.0 × 10-6).

Occurrence and air–soil exchange of organochlorine pesticides and polychlorinated biphenyls at a CAWNET background site in central China: Implications for influencing factors and fate

Ambient air and soil samples were collected between March 2012 and March 2013 at Jinsha, a regional background site in central China, to measure the concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The average concentrations of total OCPs and total PCBs were 191 ± 107 and 39.4 ± 27.1 pg/m3 in air (gaseous and particulate phase) and 0.585 ± 0.437 and 0.083 ± 0.039 ng/g in soil, respectively. The higher concentrations of p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT) and p,p′-DDT/p,p′-DDE ratios in the soil indicated recent p,p′-DDT input to the soil. A strong positive temperature dependence and average fugacity fraction value > 0.5 were observed for p,p′-DDT, suggesting that volatilization of residual DDT in the soil was the main influencing factor on atmospheric p,p′-DDT. Highly average fugacity fractions (>0.7) of trans-chlordane (TC) and cis-chlordane (CC) and high TC/CC ratios both in the soil and atmosphere suggested fresh inputs. Higher gaseous concentrations of hexachlorobenzene (HCB) were observed in winter and negative temperature dependence was directly attributed to the surrounding ongoing source (e.g. fuel consuming activities), especially in winter. Overall, most targeted OCPs and PCBs were influenced by long-range transport, and fugacity fraction values indicated highly volatile compounds (e.g. α-hexachlorocyclohexane (α-HCH) and lower chlorinated PCBs) were volatilized and low volatility compounds (e.g. p,p′-DDE and higher chlorinated PCBs) were deposited at the air–soil interface. Knowing the source and sink of OCPs and PCBs can help to control their pollution in this area and provide a reference for other studies.

Characterisation of Polychlorinated Biphenyls in Coastal Inland Seawater, Nigeria

The concentrations of polychlorinated biphenyls (PCBs) were determined in samples of surface seawater collected from five (5) different locations along the coastline of a tropical lagoon. The surface water samples were analysed using gas chromatography coupled with electron capture detector (GC-ECD) with fifteen (15) PCB congeners detected across the studied area. The chlorobiphenyls levels are in the order Ebute Ero > Oko Baba > Ijora > Lagos Island > Unilag lagoon front with levels 107.89, 53.15, 34.90, 27.78, and 2.15 mg/L, respectively. The enhanced average concentration of PCBs at the Ebute Ero site is due to the predominance of PCB-180 and PCB-185. A negative correlation was found between the total PCB concentration and the level of dissolved oxygen. Although, the results indicated fairly high levels of PCBs, the anthropogenic contributions from industrial releases and domestic activities may be largely associated with the detected concentrations of the di-, tetra-, penta-, hexa-, hepta-, and octa-chlorobiphenyls.

Distribution of OCPs and PCBs in Mussels (Mytilus galloprovincialis) from the Marmara Sea Coastal Sites

Mussel samples were collected monthly between October-2010 and October-2011 from four stations (Bosphorus, Bandırma, Gelibolu, Tekirdağ) in the Marmara Sea. Two consecutive months' samples were homogenized and combined as a single group for analysis. Mussel samples were analyzed for Organochlorine pesticides (OCPs); (total-DDT, total-HCH, Endrin, α-Endosulfan, β-Endosulfan, Heptachlor) and Polychlorinated biphenyls (PCBs); (PCB 28, PCB 52, PCB 138, PCB 153, and PCB 180). All analyses were done according to Eurofins house method in ERGO Laboratory in Germany. Concentrations of α-endosulfan and heptachlor in mussel tissues were below method detection limits. The annual average OCPs concentrations among the stations ranged between 0.02 and 1.45ng/g (wet weight), 1.9-99.75ng/g (lipid weight) whereas the annual average PCBs concentrations among the stations ranged between 0.03 and 0.40ng/g (wet weight), 1.71-26.48ng/g (lipid weight), respectively. There was no relation between fat content of mussels and residues of the contaminants. PCB 138 and PCB 153 were the most predominant PCBs, while total-DDT and total-HCH were the most predominant OCPs in the mussels. Total-DDT concentrations were higher compared to total-HCH and PCBs isomers. Measured levels were below the national and international committees' and institutions' limits for human consumption and protection of aquatic biota.

Polychlorinated biphenyls (PCBs) in sediments/soils of different wetlands along 100-year coastal reclamation chronosequence in the Pearl River Estuary, China

PCBs (polychlorinated biphenyls) were determined in sediment/soil profiles to a depth of 30 cm from three different wetlands (i.e., ditch wetlands, riparian wetlands and reclaimed wetlands) of the Pearl River Estuary to elucidate their levels, distribution and toxic risks along a 100-year chronosequence of reclamation. All detected PCB congeners and the total 15 PCBs (∑15 PCBs) decreased with depth along sediment/soil profiles in these three wetlands. The ∑15 PCBs concentrations ranged from 17.68 to 169.26 ng/g in surface sediments/soils. Generally, old wetlands tended to have higher PCB concentrations than younger ones. The dominant PCB congeners at all sampling sites were light PCB homologues (i.e., tetra-CBs and tri-CBs). According to the sediment quality guideline, the average PCB concentrations exceeded the threshold effects level (TEL, 21.6 ng/g) at most of the sampling sites, exhibiting possible adverse biological effects, which were dominantly caused by light PCB congeners. The total toxic equivalent (TEQ) concentrations of 10 dioxin-like PCBs (DL-PCBs) detected at all sampling sites ranged from 0.04 to 852.7 (10−3 ng/g), mainly affected by PCB126. Only DL-PCB concentrations in ditch and riparian wetland sediments with 40-year reclamation histories (i.e., D40 and Ri40) exhibited moderate adverse biological effects according to SQGQ values. Principal component analysis indicated that PCBs in three wetland sediments/soils mainly originated from Aroclor 1016, 1242, and 1248. Correlation analysis showed that sediment/soil organic carbon content had a significant correlation with the concentrations of several PCB congeners (P < 0.05), whereas no significant correlations were observed between any PCBs congeners and grain size or aggregate content (P > 0.05).

Selective pressurized liquid extraction technique for halogenated organic pollutants in marine mammal blubber: A lipid-rich matrix

Analytical methods for unique and rare samples, such as marine mammal tissue, strive to reduce opportunities for analyte loss and contamination. Historically, analytical methodologies for marine mammal tissues required an extraction followed by multiple cleanup and concentration steps. These steps increase the opportunity for analyte loss and sample contamination. Selective pressurized liquid extractions (SPLE; an analytical technique that combines PLE with in-cell adsorbent cleanup) have the potential to reduce and/or eliminate the number of steps. A SPLE method was developed for the simultaneous extraction of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) from bowhead whale blubber. This SPLE utilized acidic silica with a fat-to-fat retainer ratio of 0.02 as well as eliminated post-extraction cleanup steps, such as size-exclusion chromatography step. In addition, neutral silica was placed beneath the acidic silica as an acid buffer, thereby preventing acid from contaminating the extraction system. Analysis was performed using gas chromatography/mass spectrometry in electron capture negative ionization mode. PBDE, PCB and OCP triplicate recoveries averaged 84±1%, 83±3%, and 76±11%, respectively. Overall, measurements of NIST Whale Blubber SRM 1945 were within±30% of certified values. PBDEs were measured for the first time in bowhead whale blubber; average concentrations ranged from 0.2 to 1.4ngg−1 wet weight (ww). Average OCPs and PCBs concentrations ranged from 0.4 to 37ngg−1ww and 0.1 to 3.0ngg−1ww, respectively, which were within one order of magnitude lower than those previously reported in bowhead whale blubber.

Organochlorine pesticides and polychlorinated biphenyls in grass, yak muscle, liver, and milk in Ruoergai high altitude prairie, the eastern edge of Qinghai-Tibet Plateau

In highland pastures, where no agricultural and industrial activities exist, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are believed to be mainly coming from water–soil–grass system which is subject to air–water and air–soil exchanges and atmospheric precipitation. Samples of grass and yak muscle, liver, and milk were measured for OCPs and PCBs in the summer and winter of 2011. The total concentrations of HCHs, DDTs, endosulfans, HCB, and PCBs in grass samples were in the range of 0.53–2.45, 1.6–6.0, 1.10–4.38, 0.30–1.24, 0.65–2.04ngg−1 dw (dry weight), with the means 1.38, 2.86, 2.06, 0.73, and 1.19ngg−1 dw, respectively. The mean concentrations of HCHs and DDTs in yak muscle were 1.65 and 0.55ngg−1 fw (fresh weight), respectively; no significant seasonal differences. The average total concentrations of HCHs, DDTs, HCB, endosulfans, and PCBs in yak milk were 4.46, 0.59, 1.00, 0.27, and 0.097ngg−1 fat, respectively. Among the POPs investigated, β-HCH and HCB were dominant in yak muscle and liver, whereas β-HCH dominated the yak milk. Consistent with the results of other studies, PCB 153, 138, and 180 were detected in yak milk that is in accordance with the case reported for farmed cow milk in China and other countries. A human health risk was conducted based on the intake of OCPs via consumptions of the yak muscle and milk. Since the daily intake of HCHs and DDTs was lower than WHO or USEPA's acceptable daily intake or minimal risk level, showing that the consumptions of the yak muscle and milk would not pose any immediate risk to local people.

Health Risk of PCBs and DDTs in Seafood from Southern Iran

ABSTRACTLevels of polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane and its metabolites (DDTs) were measured in 18 species of fish, crab, shrimp, and bivalve samples collected from the northern region of the Persian Gulf in Iran. The levels of ∑PCBs varied from 259.92 ± 31.04 ng/g to 1648.88 ± 176.96 ng/g in lipid weight. CB118 showed the highest concentration. ∑DDT variations ranged from ND to 570.45 ± 806.74 ng/g in lipid weight. Health risk was assessed by estimating both dietary intakes and screening values (SVs). Daily intake levels were much lower than the Food and Agriculture Organization (FAO)/World Health Organization (WHO) standards for PCBs and DDTs. Based on an average bodyweight of 73 kg and consumption rates of 0.055 kg/person. day, the SVs for the carcinogen and non-carcinogen effects of PCB and DDT were calculated. Average concentrations of PCBs and DDTs showed that the levels of PCBs exceeded the established SV for carcinogens. This finding suggests the need to enhance risk management regarding seafood consumption through public advisory.

Potential for polychlorinated biphenyl biodegradation in sediments from Indiana Harbor and Ship Canal

Polychlorinated biphenyls (PCBs) are carcinogenic, persistent, and bioaccumulative contaminants that pose risks to human and environmental health. In this study, we evaluated the PCB biodegradation of sediments from Indiana Harbor and Ship Canal (IHSC), a PCB-contaminated site (average PCB concentration = 12,570 ng/g dw). PCB congener profiles and bacterial community structure in a core sediment sample (4.57 m long) were characterized. Analysis of vertical PCB congener profile patterns in sediment and pore water strongly suggests that in situ dechlorination occurred in sediments. However, 16S rRNA genes from putative PCB-dechlorinating Chloroflexi were relatively more abundant in upper 2 m sediments, as were genes indicative of aerobic biodegradation potential (i.e. biphenyl dioxygenase (bphA)). Characterization of the bacterial community by terminal restriction fragment length polymorphism and comparison of these with sediment and pore water PCB congener profiles with the Mantel test revealed a statistical correlation (p < 0.001). Sequences classified as Acinetobacter and Acidovorax were highly abundant in deep sediments. Overall, our results suggest that PCB dechlorination has already occurred, and that IHSC sediments have the potential for further aerobic and anaerobic PCB biodegradation.

Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China

Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the surface water of the East Lake, China were investigated in winter (2012) and summer (2013). A hundred and eight samples were collected from 36 sampling sites and analyzed for the 31 PCB and 10 PBDE congeners. Concentrations of both PCBs and PBDEs showed obvious seasonal variations. The average PCB concentrations in the East Lake ranged from 3.17 to 6.09ngL−1 in winter and 0.19 to 0.99ngL−1 in summer. CB-44, 105, 118 and 179 were dominant in both winter and summer. The average PBDE concentrations in the East Lake ranged from 2.92 to 5.54ngL−1 in winter and 0.67 to 1.51ngL−1 in summer. BDE-47 was predominant in both winter and summer, which accounted for more than 37% of the total PBDEs concentration from all sampling sites. Independent-Samples t-test showed statistical significance of ΣPCBs and ΣPBDEs between winter and summer samples. The analysis of distribution, pattern and seasonal variations indicated the different potential sources of PCBs and PBDEs in the East Lake. The potential eco-toxicological risk was also discussed in the study.