Assessment of exposure to PCB 153 from breast feeding and normal food intake in individual children using a system approach model

Investigators have typically relied on a single or few discrete time points as measures of polychlorinated biphenyl (PCB) body burden, however health effects are more likely to be the result of integrative exposure in time, optionally expressed as an area under the time curve (AUC) of PCB serum concentration. Using data from a subgroup of 93 infants from a birth cohort in eastern Slovakia—a region highly polluted by PCBs—we fit a system type model, customized to our longitudinal measures of serum PCB concentrations in cord, 6, 16, and 45 month blood specimens. The most abundant congener, PCB 153, was chosen for modeling purposes. In addition to currently used methods of exposure assessment, our approach estimates a concentration time profile for each subject, taking into account mean residence time of PCB 153 molecules in the body, duration of breast feeding, hypothetical PCB 153 concentration in steady-state without breast feeding and alternately without normal food intake. Hypothetical PCB 153 concentration in steady-state without normal food intake correlates with AUC (r = 0.84, p < 0.001) as well as with duration of breast feeding (r = 0.64, p < 0.001). It makes possible to determine each subject’s exposure profile expressed as AUC of PCBs serum concentration with a minimum model parameters. PCB body burden in most infants was strongly associated with duration of breast feeding in most, but not all children, was apparent from model output.     

Polychlorinated biphenyls hot and cold seasons distribution in see water,sediment, and fish samples in the Khour-e-Mousa (Mah-Shahr), Iran

The concentrations of polychlorinated biphenyls (PCBs) were assessed at four sites in Khour-e-Mousa (Mah-Shahr), Iran. Sea water, sediment and fish (cynoglossus bilineatus) samples were taken at each site and were analysed for PCB levels. To investigate the possible source of PCBs found in fish samples, sediments and waters were collected from four sites (D1, D2, D3, and D4) and studied. The relationship between PCB concentrations in sediment, water and fish is discussed. The results indicate that PCBs are detected in all fish samples and its concentration range from 3.2 to 102.7 μg kg^?1 dry weight and 5.4–149.7 μg kg^?1 dry weight in cold and warm seasons, respectively. The D2 and D4 sites were found to have the highest and lowest levels of PCB concentrations, respectively. Total congener PCB (CB, 28, 52, 44, 101, 149, 118, 153, 138, and 180) concentrations at the sediment samples for D1, D2, D3, and D4 sites ranged from 1.6 to 30.9 μg kg^?1 dry weight and 2.3–47.1 μg kg^?1 dry weight in cold and warm seasons, respectively. The total PCB concentrations for D2 site were found to be significantly higher than other three sites. Total water congener PCB (CB, 28, 52, 44, 101, 149, 118, 153, 138, and 180) concentrations ranged from 0.01 to 0.25 μg L^?1 and 0.02–0.39 μg L^?1 in cold and warm seasons, respectively.     

Atmospheric emission of polychlorinated biphenyls from multiple industrial thermal processes

In this study, field measurements were conducted to estimate and characterize the atmospheric emission levels and profiles of polychlorinated biphenyls (PCBs) from multiple industrial thermal processes. The emission levels and profiles of PCBs from five types of thermal processes at twenty-three plants were studied and compared with eight processes reported in our previous studies. Correlation analysis was preformed to identify a marker congener for emission of ΣPCB. A significant correlation was observed between congener CB-118 and ΣPCB (R² = 0.65 and p < 0.01), which suggests that CB-118 is a good marker congener for emission of ΣPCB. The profiles of PCBs emitted from the thirteen thermal processes were compared, and this information could be used for studying source–receptor relationships and identifying the specific sources of PCBs. To prioritize the sources for control, the concentrations of PCBs from thirteen industrial thermal sources were compared. The PCB concentrations from secondary zinc smelting and thermal wire reclamation were about one to three order magnitude higher than those of other sources, which suggests that these two sources be given priority in PCB source control. Finally, the atmospheric emission factors of PCBs from the thirteen industrial sources were summarized, and these data will be useful for developing an integrated emission inventory of PCBs.     

Measurement of the vapor phase deposition of polychlorinated bipheyls (PCBs) using a water surface sampler

A water surface sampler (WSS) was employed in combination with greased knife-edge surface deposition plates (KSSs) to measure the vapor phase deposition rates of PCBs to the sampler at an urban site, Chicago, IL. This sampler employed a water circulation system that continuously removed deposited PCBs. Total (gas+particle) and particulate PCB fluxes were collected with the WSS and KSSs, respectively. Gas phase PCB fluxes were then calculated by subtracting the KSS fluxes (particulate) from the WSS fluxes (gas+particle). The calculated gas phase PCB fluxes averaged 830±910 ng m⁻²d⁻¹. This flux value is, in general, higher than the fluxes determined using simultaneously measured air–water concentrations in natural waters and is in the absorption direction. This difference is primarily because the PCBs were continuously removed from the WSS water keeping the water PCB concentration near zero.Concurrently, ambient air samples were collected using a modified high volume air sampler. The gas phase PCB concentrations ranged between 1.10 and 4.46 ng m⁻³ (average±SD, 2.29±1.28 ng m⁻³). The gas phase fluxes were divided by the simultaneously measured gas phase ambient concentrations to determine the overall gas phase mass transfer coefficients (MTCs) for PCBs. The average gas phase overall MTCs (K_g) for each homolog group ranged between 0.22 and 1.32 cm s⁻¹ (0.54±0.47 cm s⁻¹). The average MTC was in good agreement with those determined using similar techniques.     

Atmospheric deposition of organochlorine contaminants to Galveston Bay,Texas

Atmospheric monitoring of PCBs and chlorinated pesticides (e.g., HCHs, chlordanes, and DDTs) in Galveston Bay was conducted at Seabrook, Texas. Air and wet deposition samples were collected from 2 February 1995 and continued through 6 August 1996. Vapor total PCB (tPCB) concentrations in air ranged from 0.21 to 4.78 ng m⁻³ with a dominance of tri-chlorinated PCBs. Dissolved tPCBs in rain ranged from 0.08 to 3.34 ng l⁻¹, with tetra-chlorinated PCBs predominating. The predominant isomers found in air and rain were α- and γ-HCH, α- and γ-chlordanes, 4,4′-DDT, and dieldrin. The concentrations of PCBs and pesticides in the air and rain revealed no clear seasonal trend. Elevated levels of PCBs in the air occurred when temperatures were high and wind came from urban and industrialized areas (S, SW, NW, and W of the site). Concentrations of HCHs were elevated in April, May, and October, perhaps due to local and/or regional applications of γ-HCH (lindane). Other pesticides showed no notable temporal variation. When winds originated from the Gulf of Mexico (southeasterly), lower concentrations of organochlorines were detected in the air. The direct deposition rate (wet+dry) of PCBs to Galveston Bay (6.40 μg m⁻² yr⁻¹) was significantly higher than that of pesticides by a factor of 5–10. The net flux from gas exchange estimated for PCBs was from Galveston Bay water to the atmosphere (78 μg m⁻² yr⁻¹). Gas exchange of PCBs from bay water to the atmosphere was the dominant flux.     

Persistent organochlorine pollutants and menstrual cycle characteristics

An evolving body of evidence suggests an adverse relation between persistent organochlorine pollutants (POPs) and menstruation, though prospective longitudinal measurement of menses is limited and served as the impetus for study. We prospectively assessed the relation between a mixture of persistent organochlorine compounds and menstrual cycle length and duration of bleeding in a cohort of women attempting to become pregnant. Eighty-three (83%) women contributing 447 cycles for analysis provided a blood specimen for the quantification of 76 polychlorinated biphenyls and seven organochlorine pesticides, and completed daily diaries on menstruation until a human chorionic gonadotropin confirmed pregnancy or 12 menstrual cycles without conception. Gas chromatography with electron capture detection was used to quantify concentrations (ng g⁻¹ serum); enzymatic methods were used to quantify serum lipids (mg dL⁻¹). A linear regression model with a mixture distribution was used to identify chemicals grouped by purported biologic activity that significantly affected menstrual cycle length and duration of bleeding adjusting for age at menarche and enrollment, body mass index, and cigarette smoking.A significant 3-d increase in cycle length was observed for women in the highest tertile of estrogenic PCB congeners relative to the lowest tertile (β = 3.20; 95% CI 0.36, 6.04). A significant reduction in bleeding (<1 d) was observed among women in the highest versus lowest tertile of aromatic fungicide exposure (γ = −0.15; 95% CI −0.29, −0.00). Select POPs were associated with changes in menstruation underscoring the importance of assessing chemical mixtures for female fecundity.     

Accumulation of hydroxylated polychlorinated biphenyls (OH-PCBs) and implications for PCBs metabolic capacities in three porpoise species

The present study investigated polychlorinated biphenyls (PCBs) and hydroxylated metabolites of PCBs (OH-PCBs) in blood from three porpoise species: finless porpoises (Neophocaena phocaenoides), harbor porpoises (Phocoena phocoena), and Dall’s porpoises (Phocoenoides dalli). The porpoises were found stranded or were bycaught along the Japanese coast. Concentrations of OH-PCB were the highest in Dall’s porpoises (58 pg g⁻¹ wet wt), second highest in finless porpoises (20 pg g⁻¹ wet wt), and lowest in harbor porpoises (8.3 pg g⁻¹ wet wt). The concentrations in Dall’s porpoises were significantly higher than the concentrations in finless porpoises and harbor porpoises (p < 0.05 and p < 0.01, respectively). There was a positive correlation between PCB and OH-PCB concentrations (r = 0.67, p < 0.001), suggesting the possible concentration-dependent induction of CYP enzymes. The three porpoise species may have exceptionally low metabolic capacities compared with other marine and terrestrial mammals, because low OH-PCB/PCB concentration ratios were found, which were 0.0016 for Dall’s porpoises, 0.0013 for harbor porpoises, and 0.00058 for finless porpoises. Distinct differences in the OH-PCB congener patterns were observed for the three species, even though they are taxonomically closely related.     

Blood levels of PCDDs,PCDFs, and coplanar PCBs in Yusho mothers and their descendants: Association with fetal Yusho disease

Maternal exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) may result in adverse health effects in their children. In Japan in 1968, an accidental human exposure to rice oil contaminated with PCDDs, PCDFs, and PCBs, led to the development of Yusho disease. Yusho mothers delivered descendants with low birth weights and hyperpigmented skin and mucosa, which are characteristic of fetal Yusho disease (FYD). The Yusho cohort was used to evaluate the effect of maternal exposure to PCDDs, PCDFs, and PCBs on the development of FYD. Blood samples, obtained from 64 Yusho mothers (117 descendants: 10 with FYD and 107 without FYD), were analyzed for congeners of seven PCDDs, 10 PCDFs, and four coplanar PCBs. We investigated the association between the maternal estimated blood levels of dioxins at delivery and the risk of fetal Yusho disease. We also studied the differences in dioxin blood levels in 24 mother–descendant pairs (5 with FYD and 19 without FYD). The estimated levels of total PCDD TEQ, total PCDF TEQ, total coplanar PCB TEQ, and total TEQ in the maternal blood at delivery were associated with significantly increased risk of FYD. The odds ratios, which present the risk of FYD for a 10-fold increase in blood dioxin, were largest for 1,2,3,6,7,8-HexaCDD (odds ratio = 28.6, 95% confidence interval = 1.67–489.9, p = 0.02). The levels of 1,2,3,6,7,8-HexaCDD in both the Yusho mothers and their descendants with FYD were higher than the levels in those without FYD. These findings suggest that 1,2,3,6,7,8-HexaCDD is the most important causative congener for the development of FYD.     

Triclosan in individual human milk samples from Australia

Triclosan is a chlorinated phenol ether that has been in widespread use as a broad-spectrum antibacterial agent for four decades. When compared to the limited international data available on human body burden of triclosan, results from a pooled blood study suggested that triclosan concentrations in Australia were a factor two higher than observed in Sweden. This study determined triclosan levels in individual human milk samples (n = 151) collected between 2002 and 2005 from primiparous Australian mothers. It provided the first report of population triclosan levels and individual variation in Australia and gave a measure of infant exposure via breast feeding. The distribution of triclosan concentration was positively skewed, with 7.2% of the samples below the LOQ, 66% with a concentration of less than or equal to 1.0 ng g⁻¹ fresh weight and the remaining samples above 1 ng g⁻¹ reaching a maximum concentration of 19 ng g⁻¹ fresh weight. The mean and median triclosan concentrations were 1.3 ± 2.7 ng g⁻¹ f.w. and 0.26 ng g⁻¹ f.w., respectively. The results of this study showed high variability in triclosan concentrations between individuals and no correlations with maternal age (p = 0.094), maternal weight (p = 0.971) or infant age at the time of sample collection (p = 0.621). A large number of samples contained low or non-quantifiable concentrations of triclosan and so, in Australia, ubiquitous background exposure due to environmental sources is low. This means that body burden can be influenced by an individual’s use of triclosan containing product. Given that triclosan containing product use is continuing, it is important that monitoring in both humans and the environment is continued and that triclosan containing products are adequately labeled so that an individual can choose to avoid exposure.     

Levels of persistent organic pollutants in air in China and over the Yellow Sea

The occurrence of persistent toxic substances (PTS) in China and possibly their regional transport in the Yellow and East China Seas region was studied. Organochlorines in atmospheric gas-phase and particulate matter were collected by high-volume sampling (filters and polyurethane foams) during 2 weeks in June 2003 (dry season) simultaneously at a Yellow Sea coastal site in an urban area, Qingdao, China, and a rural island site, Gosan, Jeju Island, Korea. Using GC methods, the samples were analysed for 9 persistent organic pollutants (POPs) regulated under the global POP convention, namely aldrin, chlordane (cis- and trans-isomers CC and TC), DDT and metabolites (o,p′-DDT, p,p′-DDD, and p,p′-DDE), dieldrin, endrin, heptachlor, hexachlorobenzene (HCB), mirex and PCB (congeners number 28, 52, 101, 153 and 180), and for hexachlorocyclohexane (α-, β- and γ-isomers), a PTS and now considered for regulation under the convention, too. At the coastal site additionally o,p′-DDE and -DDD, β-endosulfan, isodrin, heptachlorepoxide and δ-HCH, and at the island site additionally p,p′-DDT and 12 additional PCB congeners were analysed. 9 samples were collected at the coastal and 15 (for PCBs 5) at the island site. Long-range advection pathways were determined based on analysed back-trajectory calculations.The mean concentrations of DDT and its metabolites, HCB, HCH, and PCB at the coast were in the 100–1000 pg m⁻³ range. Higher concentrations prevailed during nighttime. The levels were in general lower at the island site, but not for DDT. Local sources are likely. PCBs were even 2 orders of magnitude lower, suggesting that PCBs are not subject to regional transport but elevated concentrations in air are limited to the source areas. Organochlorine pesticide levels on the other hand were seemingly determined by regional transport over Mainland China rather than by emissions in the coastal area. The currently used pesticides mirex and chlordane were found at elevated levels, i.e. 79 (6.6–255) and 36 (<6–71) pg m⁻³, respectively, at the coast but not over the island. The POPs pesticides aldrin, dieldrin and endrin, never registered in China, were mostly found at <10 pg m⁻³ except for endrin at the coastal site (up to 400 pg m⁻³) and aldrin at the island site (up to 50 pg m⁻³).     

Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling

Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990–2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p′-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79–1271 ng g⁻¹ lw) and PCBs (range: 4128–53 923 ng g⁻¹ lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs ⩾ 1). Similar results were found for PCBs (range: 1928–17 376 ng g⁻¹ lw) and PFOS (range: 104–2840 ng g⁻¹ ww) in the year 2000 and for dieldrin (range: 43–640 ng g⁻¹ lw), PCBs (range: 3491–13 243 ng g⁻¹ lw) and PFOS (range: 1332–6160 ng g⁻¹ ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQs < 1 and thus appear less likely to be linked to reproductive effects. Furthermore, sumRQs above 1 suggested risk for OHC additive effects. Thus, previous suggestions of possible adverse health effects in polar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife.     

Atmospheric PCBs and organochlorine pesticides in Birmingham,UK: concentrations,sources, temporal and seasonal trends

Concentrations of individual PCBs and DDT, DDE, α- and γ-HCH were recorded in 62 air samples of 24 h duration taken every 1–2 weeks at an urban location in Birmingham, UK between April 1999 and July 2000. Concentrations of PCBs 31/28, 52, 49, 47, 105, 149, 153, 138/164, 174, and 180 were significantly lower (p<0.05) than those recorded at the same site in 1997–1998. While DDT concentrations and DDT:DDE ratios were much lower than those recorded in southern England in 1992–1993; no such decline was observed in concentrations of α- and γ-HCH, or the α:γ-HCH ratio. These data are consistent with declining European usage of DDT, but continuing UK use of γ-HCH, and overseas use and subsequent atmospheric transport of “technical” HCH. γ-HCH concentrations displayed two non-temperature dependent peaks in spring and late summer/early autumn, consistent with agricultural use patterns. Multiple linear regression analysis was used to elucidate the relative influence of temperature, wind direction and a variety of other meteorological variables on atmospheric concentrations of PCBs. When all samples were considered, concentrations of most PCB congeners were influenced by a combination of reciprocal temperature, wind direction, and wind speed. Plotting the ratio of the Beta weightings for the regression coefficients for reciprocal temperature and sine (or cosine) of wind direction against chlorine number, revealed a general increase in the relative influence of temperature compared to wind direction with increasing chlorine number. However, when the 31 samples for which the wind speed <4.4 m s⁻¹ were analysed; only temperature and atmospheric relative humidity were influential for most congeners. This absence of influence of wind direction under relatively calm atmospheric conditions, suggests that it is medium-to-long range transport rather than local sources that exerts the greatest influence on PCB concentrations at our site.     

Seasonal variation of organochlorine contaminants in bonito (Sarda sarda L. 1758) and anchovy (Engraulis encrasicolus L. 1758) in Black Sea region,Turkey

The concentrations of indicator polychlorinated biphenyls (PCBs) and organochlorine insecticides were determined in bonito (Sarda sarda L. 1758) and anchovy (Engraulis encrasicolus L. 1758) from the Black Sea, Turkey. Concentrations of total indicator PCBs ranged between <1–17.0 in bonito, and <1–17.5 ng/g fresh weight in anchovy, and total of 1,1,1-trichloro-2,2-bis-chlorophenyl-ethane and its metabolites’ (DDTs) concentrations ranged between 13.4–26.3, and 2.96–19.0 ng/g fresh weight in bonito and anchovy respectively. PCB 52, p,p′-DDE and endosulfan (α + β) were found dominant in both of the fish species. Except endosulfan, and some DDT metabolites, none of the studied organochlorine pesticides was detected in the fish samples. Concentrations of PCBs in anchovy were found higher than those in bonito, whereas DDT and endosulfan concentrations were found similar in both of the fish species. All of the fish samples had residue concentrations below the maximum residue limits (MRL) recommended by FAO/WHO Codex Alimentarius Commission.     

Polychlorinated biphenyl spatial patterns in San Francisco Bay forage fish

Industrialized waterways frequently contain nearshore hotspots of legacy polychlorinated biphenyl (PCB) contamination, with uncertain contribution to aquatic food web contamination. We evaluated the utility of estuarine forage fish as biosentinel indicators of local PCB contamination across multiple nearshore sites in San Francisco Bay. Topsmelt (Atherinops affinis) or Mississippi silverside (Menidia audens) contamination was compared between 12 targeted sites near historically polluted locations and 17 probabilistically chosen sites representative of ambient conditions. The average sum of 209 PCB congeners in fish from targeted stations (441 ± 432 ng g^?1 wet weight, mean ± SD) was significantly higher than probabilistic stations (138 ± 94 ng g^?1). Concentrations in both species were comparable to those of high lipid sport fish in the Bay, strongly correlated with spatial patterns in sediment contamination, and above selected literature thresholds for potential hazard to fish and wildlife. The highest concentrations were from targeted Central Bay locations, including Hunter’s Point Naval Shipyard (1347 ng g^?1; topsmelt) and Stege Marsh (1337 ng g^?1; silverside). Targeted sites exhibited increased abundance of lower chlorinated congeners, suggesting local source contributions, including Aroclor 1248. These findings indicate that current spatial patterns in PCB bioaccumulation correlate with historical sediment contamination due to industrial activity. They also demonstrate the utility of naturally occurring forage fish as biosentinels of localized PCB exposure.     

High concentrations of persistent organic pollutants including PCBs,DDT, PBDEs and PFOS in little brown bats with white-nose syndrome in New York,USA

White-nose syndrome (WNS) is a condition associated with white fungal growth on ears, wings, and nose of hibernating bats; this condition has recently resulted in high bat mortality in the northeastern United States. Nevertheless, the pathogenesis of morbidity and mortality are still unknown. Elevated exposure to toxic contaminants could be a contributing factor via the consequent immunosuppression and endocrine disruption. In this study, diseased little brown bats (Myotis lucifugus) were collected from several hibernacula in eastern New York State in 2008. Fat tissues of bats were analyzed for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and organochlorine pesticides (OCPs; DDT, chlordanes, HCB, and HCH), and liver was analyzed for perfluorinated compounds (PFCs). A reference population of little brown bats, not affected by WNS, was also collected from a cave in Kentucky for the analysis of trace organic contaminants. Concentration of PCBs in fat tissues of bats from New York ranged from 1900 ng g^?1 to 35 000 ng g^?1, lipid wt, with the highest concentrations found in bats collected from caves in Albany County. High concentrations of PCBs were also found in bats from Kentucky (17 100–18 400 ng g^?1, lipid wt). Total PBDE concentrations in fat tissues ranged from 520 ng g^?1 to 10 900 ng g^?1, lipid wt, in bats from New York and from 4300 ng g^?1 to 13 000 ng g^?1, lipid wt, in bats from Kentucky. High concentrations of DDT (26 900 ng g^?1, lipid wt), chlordanes (6350 ng g^?1, lipid wt), and HCB (260 ng g^?1, lipid wt) were found in bats from New York. Concentrations of hexabromobiphenyl congener 153 (PBB 153) in bats from New York ranged from 8.6 ng g^?1 to 12 4000 ng g^?1, lipid wt. Concentrations of PFCs were on the order of a few tens to a few hundreds of nanograms per gram liver, on a wet weight basis. Overall, high concentrations of PCBs, PBDEs, DDT, and chlordanes were found in fat tissues of diseased bats from New York, although the concentrations in bats from non-diseased, reference population, from Kentucky were also high.     

Polychlorinated biphenyls and particulate organic/elemental carbon in the atmosphere of Chesapeake Bay,USA

Polychlorinated biphenyls (PCBs) and particulate organic/elemental carbon (OC/EC) differ as to sources, but are both elevated in major urban areas leading to loadings of proximate terrestrial and aquatic systems. Because of the dramatic difference in speciation, sources, and sinks of these compunds, gas+particulate phase PCBs and particulate OC/EC were measured in urban Baltimore, MD and over Chesapeake Bay at 4 and 12 h frequencies in July 1997. Gas phase ∑PCBs averaged 1180 pg m⁻³ for Baltimore and 550 pg m⁻³ for northern Chesapeake Bay. PCB homolog distributions in the gas phase differed between the land and over-water sites whereby the trichlorobiphenyls were higher in Baltimore compared to Chesapeake Bay. Autocorrelation analysis yielded a diurnal cycle for gas phase PCBs at Baltimore with the lowest concentrations observed during the day. Particulate organic and elemental carbon constituted 12.4% (17.4% organic matter) and 2.8% of total suspended particles (TSP) in Baltimore, and 15.0% (21.0% organic matter) and 5.3% over the Chesapeake Bay, respectively. Variability in PCB concentrations was not related to the variability in OC/EC concentrations. OC/EC ratios suggest that particulate organic carbon was mostly primary aerosol. Emissions of both classes of compounds into the Baltimore atmosphere and vicinity are major sources to the Bay.     

Atmospheric polychlorinated biphenyl concentrations and apparent degradation in coastal New Jersey

To characterize the atmospheric dynamics and behavior of organic compounds in the NY–NJ Harbor Estuary, atmospheric concentrations of polychlorinated biphenyls (PCBs) were measured at coastal, suburban and urban sites in New Jersey in 1997–1999. ∑PCB concentrations at the suburban site varied from 86 to 2300 pg m⁻³ and from 84 to 1100 pg m⁻³ at the coastal site. Although the temporal trends of total concentrations were significantly different at the three sites (p<0.01), PCB congener profiles revealed similar patterns (r²>0.90, p<0.001) implicating a dominant emission type and/or process. Temperature explained >50% of the total variability in ln[PCB] at both sites. Atmospheric concentrations at the suburban site increased when winds blew from an eastnortheast vector, while increased wind speeds led to a slight dilution. Wind speed and direction were not significantly correlated with the concentrations measured at the coastal site. Temporal changes in congener distribution at the suburban site are consistent with the preferential atmospheric removal of 3–5 Cl-biphenyls by hydroxyl radical attack with estimated half-lives of 0.7–1.8 years.     

Bioaccumulation of polybrominated diphenyl ethers in harbor seals from the northwest Atlantic

Polybrominated diphenyl ethers (PBDEs) were analyzed in blubber of harbor seals (Phoca vitulina concolor) collected between 1991 and 2005 along the northwest Atlantic. ∑PBDE concentrations (mono- to hexa-BDEs) detected in blubber samples (n = 42) ranged from 80 to 25 720 ng g⁻¹ lw, (overall mean 2403 ± 5406 ng g⁻¹ lw). By age, mean ∑PBDE concentrations were: 3645 ± 7388, 2945 ± 5995, 1385 ± 1265, and 326 ± 193 ng g⁻¹ lw in pups, yearlings, adult males, and adult females, respectively. Unlike the trend for PCBs, no decreasing gradient from urban to rural/remote areas was observed for PBDEs in these samples, likely reflecting inputs from local sources. No significant temporal trend was observed for PBDEs in harbor seals between 1991 and 2005, although congener profiles shifted over time. Tetra-BDE-47 was the dominant congener, followed by BDEs-99, -100, -153, -154, and -155 in varying order, suggesting exposure to the penta-BDE product. In adult males, the hexa-BDEs contributed more to the total (22%) than BDEs-99 and -100 (14%), and concentrations of BDE-155 were elevated compared with -154. Higher BDEs were detected in a subset of seals (n = 12) including hepta-BDE-183, the marker for the octa-BDE mixture, and octa-BDE-197, along with several unidentified hepta- and octa- congeners. BDE-209 was detected in seal blubber at concentrations ranging from 1.1 to 8 ng g⁻¹ lw, indicating that deca-BDE is bioavailable in this marine food web. This is the first study to document the accumulation of BDE-209 at measurable levels in wild harbor seals. While the PBDE patterns in blubber indicate exposure to all three BDE commercial mixtures, the data also suggest that BDE-209 debromination by seal prey fish may contribute to the loading of lower brominated congeners (hexa- to octa-BDEs) in these seals.     

Persistent organochlorine pesticide and PCB residues in surface sediments of Lake Qarun,a protected area of Egypt

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in sediment samples collected from 34 locations in Lake Qarun, Egypt to elucidate their concentrations, distribution, possible sources and potential ecological risk. A total of 25 OCPs and 29 PCBs were identified and quantified. OCPs and PCBs were found to be ubiquitous pollutants in the aquatic environment of Lake Qarun, particular near urban areas reflecting the local usage and input of these pollutants. Total concentrations of OCPs and PCBs in sediments ranged from 1.01 to 164.8 ng g^?1 and 1.48 to 137.2 ng g^?1, respectively. Among OCPs, γ-HCH, heptachlor, aldrin, endrin, p,p′-DDE, oxy-chlordane and endosulfan I and II were the most abundant compounds. The composition of PCB congeners was dominated by the tri-, tetra-, penta- and hexa-chlorinated biphenyls. The ratios of certain metabolites (isomers) to their parent compounds (mixtures) indicated there are still new inputs of lindane, endrin, heptachlor and technical endosulfan to Qarun Lake, while the ratios of (p,p′-DDE + p,p′-DDD)/∑p,p′-DDTs indicate earlier usage of DDT. Contamination levels of PCBs and HCHs can be categorized as moderate to high compared to other urbanized regions worldwide. According to established sediment quality guidelines, γ-HCH, endrin and chlordanes would be more concerned OCP species for the ecotoxicological risk in Lake Qarun.     

Polychlorinated biphenyls (PCBs) and Polybrominated Diphenyl ethers (PBDEs) in three fish species from an estuary in the southeastern coast of Brazil

Polychlorinated biphenyls (PCBs) and Polybrominated Diphenyls Ethers (PBDEs) are two highly lipophilic classes of persistent organic pollutants able to resist degradation and with the ability to bioaccumulate through the food chain. In Brazil, there are still few studies on PCBs and PBDEs in aquatic organisms. In this study, we determined the levels of PBDEs and PCBs in three different fish species from the Ilha Grande Bay, located in the southern state of Rio de Janeiro, Brazil. PBDEs levels were very low, with values below the limit of quantification. PCBs concentrations ranged from 2.29 to 27.60 ng g^?1 ww in muscle and from 3.41 to 34.22 ng g^?1 ww in liver of the three investigated fish species. Significant positive correlations were established between PCBs concentration and fish biometric variables in mullet (length and lipid content) and a statistically significant change between seasons in croaker was observed.