Differences In PCB Concentrations Research Articles

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

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

Residential exposure to airborne polychlorinated biphenyls and risk of cardiovascular diseases: A register-based cohort study

Background and aim Polychlorinated biphenyls (PCBs) are biopersistent chemicals ubiquitously present in our environment. Although exposure to lower-chlorinated PCBs (LC-PCBs) evaporating from building materials to indoor air is relatively common, the long-term cardiovascular effects remain unknown. We aimed to examine the risk of cardiovascular disease (CVD) following residential exposure to PCBs in indoor air. Methods The study builds on the register-based Health Effects of PCBs in Indoor Air (HESPAIR) cohort of 51,921 residents of two residential areas near Copenhagen: Farum Midtpunkt and Brøndby Strand Parkerne. Here, indoor air was contaminated with PCB in one third of the apartments. Indoor air measurements in subsets of apartments have documented large differences in PCB-concentrations between contaminated and uncontaminated apartments, dominated by LC-PCBs. Individual PCB-exposure was based on relocation dates from nation-wide registers and indoor air PCB-measurements and calculated as PCByear. CVD Information was retrieved from the Danish National Patient Register for the follow-up period 1977–2018. We estimated hazard ratios using Cox regression analyses with time-varying exposure adjusting for a priori identified potential confounders. Results Residential exposure to airborne PCB was not associated with a higher overall risk for CVD (HR for highly exposed: 1.02, 95% CI 0.95-1.11). The same was the case for most of the specific cardiovascular diseases apart from acute myocardial infarction where a 17% higher risk was observed for residents exposed to ≥3300 ng/m3*year compared to the reference group (HR 1.17, 95% CI 1.01-1.36). Conclusions In this first study to examine CVD risk following residential exposure to PCBs in indoor air, we observed only limited support for cardiovascular effects of living in PCB-contaminated air. Considering the prevalence of exposure to airborne PCBs and lack of knowledge on their potential health effects, these findings need to be corroborated in future studies. Key words lower-chlorinated PCBs; cardiovascular toxicity; environmental epidemiology; environmental pollutants

Historical data review and source analysis of PCBs/Arochlors in the Lower Leon Creek Watershed

PCBs have been banned since the late 1970s, but concentrations still exist in sediments and riverine fish and continue to exceed regulatory limits which can result in negative health effects. This study looks at historical records of PCB and Arochlor concentrations in surface water, sediments, and fish tissue for the Lower Leon Creek, Bexar County in Texas. Temporal analysis on the concentrations of PCBs and Arochlors was conducted for detection and exceedance of selected screening criteria. In addition, the half-lives of select PCB congeners were calculated for 2007-2012 data to ascertain differences in PCB concentrations with their hydrophobicity. Source analysis was conducted to determine the potential contributing sources of PCB contamination using source data (landfills, outfalls, etc.) and the PCB exceedance data. For sediment and fish tissue sampling results, historic data shows high concentrations of PCB/Arochlors over the course of several decades. The historical data is characterized as being widely variable for detections in Arochlors and concentrations between years, with a dramatic drop in concentrations detected starting in 2009. Overall, the sampling locations adjacent to and downstream from the former Kelly Air Force Base have the highest concentrations of PCB/Arochlors over the longest period of time. The results of this work will aid regulatory agencies in addressing impairment.

PCB Levels in Humans in an Area of PCB Transformer Recycling

PCB levels in environmental, food, and human samples were determined around a highly PCB-contaminated town (F town), a less contaminated town (P town), and a control town (DXG). There were significant differences in PCB concentrations in the intravenous blood of the mothers and their children living in F, P, and DXG sites. In F town, PCB concentrations in the blood of the mothers averaged 190 mug/kg lipid, as compared to 97 mug/kg lipid in the control site. PCB concentrations in the blood of boys and girls averaged 222 and 153 mug/kg lipid, respectively, in F town. PCB concentrations in the umbilical cord blood averaged 566.8 and 168.2 mug/kg lipid, respectively, in the more seriously (F town) and less seriously (P town) polluted sites. Concentrations in the fetal excreta of the newborns averaged 100.06 and 1.66 mug/kg lipid, respectively, in these sites. PCBs were detected in surface water, underground water, soil, and vegetables, and have spread in a circumference of 30 km from the PCB source and have accumulated in the food chains from surface water to fish and duck eggs and from soil to chickens and pigs. The inhabitants have taken in PCBs through these foods since the 1970s. The results implicate the e-waste recycling operations as having caused elevated PCB levels in the environment and in humans. The elevated exposure levels may have health implications for the next generation.

Evaluation of Noninvasive Approach for Monitoring PCB Pollution of Seabirds Using Preen Gland Oil

Oil secreted from the preen gland (located at the base of the tail feathers) of seabirds can be collected from live birds. We determined PCB concentrations and profiles in the preen gland oil and corresponding abdominal adipose tissue collected from 30 seabirds (2 orders, 3 families, 10 genera, 13 species) to examine the utility of the oil as a monitoring medium. Samples were collected from seabirds that had died in traffic accidents or had become caught unintentionally in experimental drift nets and long-lines in the North Pacific Ocean. Significant concentrations of PCBs were detected in all oil samples, with a concentration range of 9-4834 ng/g-lipid and a geometric mean of 404 ng/ g-lipid. PCBs in the oil had more lower-chlorinated congeners than those in corresponding abdominal adipose, suggesting that they had less opportunity to undergo metabolism before they were secreted from the gland. We observed a weak but significant correlation between the PCB concentrations in the oil and abdominal adipose tissue (R2 = 0.19, P < 0.05). Correcting for the metabolic loss of PCBs on the basis of congener profiles improved the correlation (R2 = 0.48, P < 0.001), implying that congener-specific determination of PCBs in the preen gland oil enables us to estimate PCB concentrations in the abdominal adipose within 1 order of magnitude difference. The differences in PCB concentrations among the 13 species are discussed in terms of dietary behavior, habitat, and migration.

Variations in PCB concentrations between genders of six warmwater fish species in Lake Logan Martin, Alabama, USA

We collected and analyzed 955 individual fish (six species) for sexual differences in PCB bioaccumulations from a southeastern, USA reservoir. Using 2-way ANCOVAs, we found significant differences in fillet PCB concentrations between sexes for channel catfish (Ictalurus punctatus), largemouth bass (Micropterus salmoides) and spotted bass (Micropterus punctulatus). Striped bass (Morone saxatilus), black crappie (Pomoxis nigromaculatus) and freshwater drum (Aplodinotus grunniens) did not display differences between sexes in PCB concentrations. We suspect that sexual differences may be due to biological differences in reproduction, relative motility and lipid deposition. For one species (striped bass), sexual differences in PCB concentrations were inconsistent with a study in the Hudson River suggesting that sexual differences in bioaccumulations can change across ecosystems. Two species which did show sexual differences, largemouth bass and channel catfish, are often chosen as representative species (e.g., "piscivore" and "benthivore") in contaminant monitoring in many USA states indicating human consumption and risk management decisions would be improved if an equal number of male and female fish were included in composite PCBs analysis. This could reduce variability in fish PCBs data from which consumption advisories are based.

Summer Food Habits of Pumpkinseeds ( Lepomis gibbosus) and Bluegills ( Lepomis macrochirus) in Presque Isle Bay, Lake Erie

Zebra mussels ( Dreissena polymorpha) and quagga mussels ( D. bugensis) have received much attention since they were first reported in the Great Lakes. Predation by fishes may be an important factor in regulating dreissenid populations, but the extent to which fish prey on them is not entirely clear. Pumpkinseeds ( Lepomis gibbosus) are known to be effective predators of mollusks, but bluegills ( Lepomis macrochirus) do not generally prey heavily on mollusks. Analysis of stomach contents of pumpkinseeds and bluegills collected from Presque Isle Bay of Lake Erie (Erie, Pennsylvania) revealed considerable differences in the diets of the two species. Specifically, dreissenids were the most important food item in the diet of pumpkinseeds and composed 63% of the volume of their diet. In contrast, dreissenids were relatively unimportant in the diet of bluegills and composed only 2.3% of the volume of their diet. Although bluegills and pumpkinseeds differed considerably in their consumption of dreissenids and other prey items, no clear differences in PCB concentrations were detected between the two species. Thus bluegills must acquire most of their PCBs from prey other than dreissenids.

Bioaccumulation of PCBs in Arctic seabirds: influence of dietary exposure and congener biotransformation

Four seabird species and their prey (zooplankton or fish) were collected in the Barents Sea to determine how dietary exposure, cytochrome P450 (CYP) enzyme activities and sex influenced their hepatic PCB concentrations and accumulation patterns. Five males and five females from each seabird species (little auk ( Alle alle), Brünnich's guillemot ( Uria lomvia), black guillemot ( Cepphus grylle) and black-legged kittiwake ( Rissa tridactyla)) were analysed. PCB concentrations could not be explained directly by carbon source ( δ 13C) or trophic position ( δ 15N), but by a combination of dietary parameters ( δ 13C, δ 15N, migratory pattern, age) and contaminant metabolism. Contrary to previous studies, the PCB pattern differed among seabirds, with a higher proportion of persistent congeners (% of PCB-153, R PCB-153) in black-legged kittiwake than in auks. The PCB pattern also differed among auks, with little auk as the most efficient biotransformer (highest R PCB-153 values of persistent congeners). Based on high R PCB-153 values, Brünnich's guillemot poorly metabolised ortho– meta-unsubstituted congeners, whereas black guillemot poorly metabolised meta– para unsubstituted congeners. Species-specific differences in PCB biotransformation were confirmed by metabolic indices, where PCB patterns in seabirds were adjusted for PCB pattern in prey. The relative contribution of ortho– meta-unsubstituted congeners to ∑PCBsdecreased with increasing EROD activity. There were no differences in PCB concentrations, PCB patterns or cytochrome P450 enzyme activities between males and females. CYP P450 activities (CYP1A- and CYP2B/3A-like: EROD and testosterone 6β-hydroxylation, respectively) were low and did not correlate with concentrations of non- or mono- ortho Cl-substituted PCBs (NO- and MO-PCBs), or with total toxic equivalent concentrations (TEQs) for dioxin-like effects of NO- and MO-PCBs.

Impacts from PCB accumulation on amphibians inhabiting streams flowing from the Paducah Gaseous Diffusion Plant.

Contamination at the Paducah Gaseous Diffusion Plant (PGDP), Paducah, Kentucky, has been under evaluation for many years. We studied amphibians in selected outfalls (drainage ditches) flowing from the PGDP to determine if PCBs were accumulating in their tissues and how this might affect local populations. We determined relative amphibian species richness and abundance among seven outfalls and three reference streams by listening to their calls during audio surveys. We also captured amphibians from each study site during the summers of 2000 and 2001 and analyzed their carcasses for PCBs (Aroclor 1260 and 34 congeners) and livers for ethoxyresorufin O-deethylase (EROD) activity, a biomarker of PCBs and other organic contamination. Ten species were heard across study sites, and abundance and richness at outfalls were similar to those observed at reference sites. However, there were significant differences in abundance (p = 0.001) and richness (p = 0.048) of amphibians between continuously flowing and intermittent outfalls. There were no significant differences in PCB concentrations (p = 0.113) in amphibians captured from study sites, although Aroclor 1260 concentrations tended to be higher in amphibians collected from one outfall (outfall 12) on the east side of the plant (x = 1260 microg/kg) compared with all other study sites (x = 489 microg/kg). EROD activity measured in the liver was not indicative of Aroclor 1260 concentrations in amphibians at the PGDP, and EROD did not differ by study site, species, age class, or gender. PCB concentrations measured in amphibians at the PGDP were similar to concentrations measured at reference sites and did not appear to negatively affect individual amphibians or abundance and richness.

PCB in soils and estimated soil–air exchange fluxes of selected PCB congeners in the south of Sweden

PCB concentrations were studied in different soils to determine the spatial variation over a region of approximately 11 000 km 2. PCB congener pattern was used to illustrate the spatial differences, as shown by principal component analysis (PCA). The relationship to different soil parameters was studied. PCB concentrations in soil showed a large variation between sampling-areas with median concentrations ranging between 2.3 and 332 ng g −1 (dw). Highest concentrations were found at two sites with sandy soils, one with extremely high organic carbon content. Both sites were located on the west coast of southern Sweden. Soils with similar soil textures (i.e. sandy silt moraine) did not show any significant differences in PCB concentrations. PCB congener composition was shown to differ between sites, with congener patterns almost site-specific. PCB in air and precipitation was measured and the transfer of chemicals between the soil and air compartments was estimated. Soil–air fugacity quotient calculations showed that the PCBs in the soil consistently had a higher fugacity than the PCBs in the air, with a median quotient value of 2.7. The gaseous fluxes between soil and air were estimated using standard modelling equations and a net soil–air flux estimated by subtracting bulk deposition from gaseous soil–air fluxes. It was shown that inclusion of vertical sorbed phase transport of PCBs in the soil had a large effect on the direction of the net soil–air exchange fluxes.

Polychlorinated biphenyls in the air of southern Sweden – spatial and temporal variation

Polychlorinated biphenyls in the lower atmosphere were studied over a regional area covering approximately 11 000 km 2 in southern Sweden. Sampling were performed in 1992–1993, continuously during one year, where samples from 11 sampling-sites (in all 260 samples) were analysed. PCB concentrations ranged over two order of magnitudes, 7–983 pg m −3. Differences in PCB concentrations among the sampling sites revealed a large number of high-concentration outliers, mainly originating from one suburban site. Smaller differences in PCB concentrations between sites probably originated from varying geographical and meteorological conditions, that affected exchange processes between air and surfaces differently at the sampling sites.

Flux of transuranium nuclides and chlorinated hydrocarbons in the northwestern Mediterranean

The transuranium nuclides, plutonium and americium, and selected chlorinated hydrocarbon compounds have been measured in sediment trap samples, bottom sediments and waters. These measurements have been used to quantify vertical fluxes and elucidate particulate biogeochemical cycles, of these man-made contaminants in the northwestern Mediterranean. Sediment trap experiments in the Gulf of Lions (Lacaze-Duthiers Canyon) have shown that transuranic fluxes are considerably higher in the Gulf of Lions, than those which have been reported for the northeast Pacific; principally this is due to the relatively high mass fluxes in this region of the Mediterranean. Water, surface sediment and sediment trap data indicate that 241Am is being transported downward (via particle settling) more rapidly than 239+240 Pu. From direct flux measurement, residence times for 239+240 Pu and 241Am in the upper 300 m were computed to be 2.5 and 0.14 years, respectively. Comparison of 239+240 Pu concentrations in the water column, in 1986, with similar measurements made 5–11 years earlier suggests that fallout input to the Mediterranean has decreased by nearly a factor of 2 during the period 1975–1986. Fluxes of PCB, HCB, γ-HCH and DDT residues varied by as much as an order of magnitude, or more, both temporally and with depth. The average fluxes of most of the compounds in the Lacaze-Duthiers Canyon, during 1985–1986, were quite similar to those measured off the coast of Monaco several years earlier. Generally, the increased chlorinated hydrocarbon fluxes observed with depth were a direct result of the much higher mass fluxes which occurred at depth. Demonstrated differences in PCB concentrations in the settling particles, deposited surface sediments and overlying sediment floc indicate that simple bottom sediment resuspension is not a major contributor to the enhanced PCB flux noted at depth. The PCB concentration in sedimenting particulate material collected from deeper waters, is similar to previously analysed benthic flocs; it is likely to have been advected into the canyon with the nepheloid layer, which is a common oceanographic feature in this region.