PCB Congeners Research Articles

Spatial and temporal analysis of the risks posed by polycyclic aromatic hydrocarbon, polychlorinated biphenyl and metal contaminants in sediments in UK estuaries and coastal waters

The environmental risks of 22 contaminants, comprising 6 metals, 10 PAHs and 6 PCB congeners occurring in UK estuaries and coastal waters were assessed as single substances. Sediment samples were taken within 12 nautical miles of the English and Welsh coastlines between 1999 and 2011. The measured environmental concentrations were compared to quality standards including ERL, ERM and EAC, all of which have been established internationally. Out of a total of 38,031 individual samples analysed, 42.6% and 7.7% exceeded the ERL/EAC and ERM values, respectively. The highest Risk Characterisation Ratios (RCRs) for metals, PAHs and PCBs were observed for copper, fluorene and CB118 (2,3′,4,4′,5-pentachlorobiphenyl). In general, the highest concentrations of PAHs and PCBs were observed in 2011 in the Lower Medway indicating a potential risk to the aquatic environment. This study suggests that re-suspension of contaminants banned over 20years ago is still an ongoing issue.

Intervention to reduce PCBs: learnings from a controlled study of Anniston residents.

Nonabsorbable dietary lipid reduces the absorption of dietary PCBs and increases the excretion of previously absorbed stored PCBs. Absorption of all PCB congeners will presumably be interrupted by nonabsorbable lipid; however excretion will be enhanced only for PCBs that have not been metabolized and also for their lipophilic metabolites. Our study with the nonabsorbable lipid, olestra, in a controlled trial in Anniston residents with elevated PCB levels demonstrated that it is possible to enhance removal of PCBs from the body in the clinically meaningful time frame of 1 year. The rate of disappearance of PCBs in participants who ate 15 g/day of olestra was significantly faster than the rate determined during the 5 years prior to intervention. The rate of disappearance was not changed from the pretrial rate in participants who ingested vegetable oil. Consideration of the role of body weight and fat is an important factor in the design of intervention trials of this kind, and the results of this trial suggest that the level of body fat in individuals will influence the rate of removal from the body. Previously reported data from animals and from a case report indicate that weight loss combined with nonabsorbable dietary lipid will maximize removal of PCBs and presumably other stored organochlorine compounds. The design of future intervention trials should include a focus on body fat levels and changes. Future trials should also include the testing of dietary compounds other than olestra that have affinity for PCBs, such as plant-derived polyphenols.

Polychlorinated biphenyls and polybrominated biphenyl ethers in adipose tissue and matched serum from an E-waste recycling area (Wenling, China)

To Date, the knowledge on relationship between PCBs/PBDEs exposure and thyroid hormones (THs) levels during pregnancy still needs to be extended. Meanwhile, studies on congener-specific adipose-serum ratios for PCBs/PBDEs were limited. This study reports the levels of PCBs/PBDEs in serum-adipose tissue samples (n = 64) from expectant women living surrounding e-waste recycling sites in Wenling, China. Their concentrations varied from several to hundreds of ng g−1 lipid. Maternal exposure to PCBs was associated with lower TSH during pregnancy, suggesting possible implication for maternal health and fetal development. The compound levels between the adipose tissue and matched serum samples were highly correlated (p < 0.001), generating a predicted adipose-serum partitioning relationship for individual PCB congener and PBDE congener. Molecular characteristics, such as Kow value, molecular weight and molecular volume, may play a key role in the variable partitioning of some compounds between serum and adipose tissue.

Comparison of the in vitro effects of TCDD, PCB 126 and PCB 153 on thyroid-restricted gene expression and thyroid hormone secretion by the chicken thyroid gland

The aim of this study was to compare the in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) and 2,2′4,4′,5,5′-hexachlorobiphenyl (PCB153; non-coplanar PCB) on mRNA expression of thyroid-restricted genes, i.e. sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and thyroid hormone secretion from the thyroid gland of the laying chicken. Relative expression levels of NIS, TG and TPO genes and thyroxine (T4) and triiodothyronine (T3) secretion from the thyroidal explants were quantified by the real-time qPCR and RIA methods, respectively. In comparison with the control group, TCDD and PCB 126 significantly increased mRNA expression of TPO and TG genes. TCDD did not affect NIS mRNA levels, but PCB 126 decreased its expression. No effect of PCB 153 on the expression of these genes was observed. TCDD and PCB 126 significantly decreased T4 and T3 secretion. There was no significant effect of PCB 153 on these hormone secretions. In conclusion, the results obtained show that in comparison with non-coplanar PCB 153, TCDD and coplanar PCB 126 can directly affect thyroid hormone synthesis and secretion, and in consequence, they may disrupt the endocrine function of the thyroid gland of the laying chicken.

Seasonal Variation and Gas/Particle Partitioning of PCBs in Air from Central Urban Area of an Industrial Base and Coastal City -Tianjin, China

ABSTRACTThe 26 air samples were collected from Tianjin urban areas from July 2010 to May 2011 for the analysis of 86 PCB congeners to investigate the gas/particle partitioning of PCBs. The total PCBs concentration (in pg/m3) ranged from 31.28 to 650.33 (mean: 273.77) and showed a significantly seasonal variation as summer > autumn > spring > winter. Gas PCBs accounted for 80.79% of total PCBs. The fraction of each gas PCB homolog increased with the decreasing chlorine atoms. The contribution of gas PCBs to total PCBs showed a strong seasonal variation with summer (94.07%) > autumn (78.91%) > spring (78.19%) > winter (56.02%). Tri-, tetra- and penta-PCBs were the predominantly homologs in Tianjin atmosphere. The natural logarithm of partial pressure of PCBs were well correlated with the inverse absolute environmental temperature (R = 0.79). The steep slope of –4933.64 obtained from Clausius–Clapeyron (C.C) plot indicated the influence of local PCBs sources. In generally, the C.C slopes and the surface-air exchange enthalpy (∆HSA) for different PCB homologs increased with the increasing chlorine atoms. The fraction of particle bound PCBs were underestimated for PCBs with PL0 > 10–3.85 Pa and overestimated for PCB congeners with PL0 < 10–3.85 Pa by Junge-Pankow model. The logarithm of particle/gas partitioning coefficients (log KP) of PCBs were well correlated with the logarithm of respective sub-cooled vapor pressures (log PL0) (R = 0.72) and the octanol-air partition coefficient (log KOA) (R = 0.77). The slopes for log KP against log PL0 and log KOA plots were –0.44 and 0.48, deviated significantly from the expected –1 and +1 for the equilibrium state of gas/particle partitioning, possibly explained by the emission of PCBs and particles from the local industries and other sources. The TEQ concentrations (fg/m3) for 12 dioxin-like PCB congeners ranged from 35.628 to 612.796 with the mean value as 144.878.

Distribution of polychlorinated biphenyl residues in sediments and blue mussels (Mytilus galloprovincialis) from Port Elizabeth Harbour, South Africa

Sediment and Mytilus galloprovincialis samples collected from the Port Elizabeth Harbour were analysed for six indicator PCB congeners to assess their contamination status. The concentrations of total PCBs in sediments and M. galloprovincialis ranged from 0.56 to 2.35ng/g dry weight and 14.48 to 21.37ng/g wet weight, respectively. Congeners 138 and 153 were dominant and accounted for an average of 29% and 24% of total PCBs in M. galloprovincialis; 32% and 30% in sediments, respectively. Sediments are home to a wide variety of aquatic life. None of the sediments analysed exceeded the PCB limits recommended the Canadian interim sediment quality guideline and the South African recommended sediment guidelines (21.6ng/g). Both humans and aquatic life are sensitive to the toxic effects of PCBs.

Prenatal Polychlorinated Biphenyls Exposure and Semen Quality in Adult Male Offspring: Results from the Child Health and Development Studies

Introduction In some cross sectional studies exposure to PCBs is associated with reduced sperm quality; however, only one small study has investigated prenatal exposure. Methods In a sample of 195 adult men whose mothers were enrolled in Child Health and Development studies in the 1960s, we measured 15 PCB congeners in maternal early postpartum serum in relation to sperm concentration, motility, and morphology in men ages 39 to 47. Linear regression was used to estimate the associations between maternal serum PCB levels and semen parameters, adjusting for potential confounders. Results Higher levels of PCB105 in maternal serum predicted increased sperm concentration in adult sons (estimated adjusted b = 1.9; 95% Confidence Interval (CI) (0.3-3.4)). Higher maternal serum PCB74 predicted increased sperm motility (estimated adjusted b = 24.9; 95% CI (1.9, 48.0)). In contrast, higher maternal serum PCB183 predicted decreased motility (estimated adjusted b= -41.04. 95% CI (-74.7, -7.4)) and higher maternal serum PCB66 and PCB156 predicted decreased percent normal sperm morphology (estimated adjusted b=-4.1; 95% CI (-8.0, -0.3) and estimated adjusted b=-7.1; 95% CI (-13.8, -0.5), respectively Conclusion Maternal perinatal serum levels of five specific PCB congeners predicted measures of semen quality in adult sons. Interestingly, maternal perinatal serum levels of three of these PCBs (105, 183 and 156) also predicted time to pregnancy in adult daughters in the Child Health and Development Studies in a prior report. Findings suggest that perinatal exposure to these three PCBs may result in lasting endocrine disruption in both sexes.

PCB concentrations in plankton size classes, a temporal study in Marseille Bay, Western Mediterranean Sea

PCB levels in plankton were investigated in the Bay of Marseille, Western Mediterranean Sea, between September 2010 and October 2011. Concentrations of PCB congeners (CB 18, CB 52, CB 101, CB 118, CB 138, CB 153, CB 180) were determined in three plankton size-classes (60–200, 200–500 and 500–1000μm) together with different parameters: chlorophyll content, plankton dry-weight biomass, carbon and nitrogen stable isotope ratios and plankton-community structure. The ∑PCB7 concentrations ranged between 14.2 and 88.1ngg−1d.w., for all size classes and all sampling periods. The results do not show the biomass dilution effect and indicate moderate but significant biomagnification with plankton trophic position estimated by δ15N signatures. Equilibrium with water phase may notably contribute in controlling the PCB levels in the plankton. More generally, presented results imply that PCB accumulation in the plankton is an effect of abiotic and trophic complex interactions in the Bay of Marseille.

Distribution and Toxicity Risks of PCBs in the Tidal Flat Ecosystem Near the 37th PCBs Sealed Site on the Coast of Zhejiang Province, China

ABSTRACTThis study investigated the dioxin-like (DL) PCB concentration and congener distributions in water, sediment, and Boleophthalmus pectinirostris samples collected from a beach near the 37th PCBs sealed site (the hazardous waste storage site was sealed by Zhejiang Province Environmental Monitoring Center) of Zhejiang Province, China, so as to evaluate the harmful effects of PCBs waste sealed sites on the surrounding environment. The results showed that DL-PCBs were in all samples. For all samples, the detection ratio of the mono-ortho congener PCB118 and the non-ortho congener PCB81 reached 100%, and both of their contents correlated well with the total DL-PCBs contents. Levels of low-chloride congeners were higher in environmental samples, while the enrichment of the high-chloride congeners was higher in fish. The content of PCBs in B. pectinirostris was highly related to the sediment environment, thus B. pectinirostris could well indicate environmental PCBs pollution. Considering both of the PCBs content and toxic analysis, even after 4 years of being excavated and cleaned, water, sediment, and fish samples were still at a certain degree of toxicity risks. Some areas were revealed to have a high toxicity risk, suggesting this PCBs sealed site still posed toxicity risks to the surrounding tidal flat ecosystem and might potentially endanger animals and human health.

Uptake of PCBs contained in marine sediments by the green macroalga Ulva rigida

The uptake of PCBs contained in marine sediments by the green macroalga Ulva rigida was investigated in both laboratory and field experiments. Under laboratory conditions, total PCBs (tPCBs) uptake was significantly greater in live vs dead plants. The concentration of tPCB taken up in live plants was greatest in the first 24h (1580μgkg−1 dry weight), and then increased at a lower rate from day 2 to 14. Dead plants had a significantly lower tPCB concentration after 24h (609μgkg−1 dry weight) and lower uptake rate through day 14. Lesser chlorinated PCB congeners (below 123) made up the majority of PCBs taken up. Congener composition in both laboratory and field experiments was correlated to congener logKow value and sediment content. Field experiments showed that Ulva plants could concentrate PCBs to 3.9mgkg−1 in 24h. Thus, U. rigida is capable of removing PCBs in sediments at a rapid rate.

Persistent organic pollutants (PCBs and OCP) in air and soil from Ulaanbaatar and the Lake Hovsgol region, Mongolia

The investigations of POPs in soil and air in three urban and rural sites of the Mongolia are presented. The POPs distribution in air repeats the POPs distribution in soil on the area investigated. The POPs levels in soil and air are lower than maximum permissible concentrations (MPC) and preliminary permissible concentrations (PPC) of PCBs and OCP accepted in Russia. POPs levels in Mongolian soil obtained in the investigation are comparable with those from background areas of the world. POPs levels in Mongolian air are in the frame of concentrations found in the world. The PCB homological pattern in soil near electric power station in Ulaanbaatar is close to homological pattern in PCB technical mixture (Sovol or Arochlor 1254). The homological patterns in soil from other sites changed due to the redistribution of PCB congeners in the environment. The ratio of DDT and its metabolites indicates fresh entrance of DDT in the environment of Mongolia due to the atmospheric transboundary transport from countries using DDT (China, India) or from local agricultural sources. Hazard indexes in result from human exposure with POPs in soil and air are lower by 2-4 orders than 1 that denotes the possible default of disturbances in target organ and system. CR under the same scenario corresponds to the first diapason that is taken by population as negligible risk, not differ from usual everyday risks. Such risks don’t require additional measures for the reducing of risks and their levels are a subject of periodical control. The necessity of additional investigation of POPs distribution and the fate in Mongolian environment is indicated.DOI: http://dx.doi.org/10.5564/mjc.v12i0.176 Mongolian Journal of Chemistry Vol.12 2011: 69-77

Distribution and sources of PCBs (Aroclor 1268) in the Sapelo Island National Estuarine Research Reserve

Aroclor 1268 is a highly chlorinated PCB mixture that was released into the aquatic environment near Brunswick, GA (BR), as a result of decades of local industrial activity. This extensive contamination has led to US EPA Superfund designation in estuarine areas in and around Purvis Creek, GA. Roughly 50km to the northeast is the Sapelo Island National Estuarine Research Reserve (SI) where previous studies have documented unexpectedly high Aroclor 1268-like PCB levels in blubber and plasma samples of resident bottlenose dolphins. This result led to a collaborative effort to assess the PCB patterns and concentrations in SI sediment and fish (as potential vectors for PCB transfer to SI resident dolphins). Thirty SI randomly assigned stations were sampled for sediment PCB levels. Additionally, fish were collected and analyzed from SI (n = 31) and BR (n = 33). Results were pooled with regional assessments of PCB concentrations from South Carolina and North Carolina in an effort to determine the association of Aroclor 1268 levels in SI samples. Results indicated that PCB levels in sediment and fish are much lower in the SI estuary compared to BR sediment and fish concentrations. However, PCB congener profiles for both sediments and fish were similar between the two locations and consistent with the Aroclor 1268 signature, indicating possible transport from the Brunswick area. A likely source of Aroclor 1268 in dolphins from SI is contaminated fish prey.

Influence of redox conditions on the microbial degradation of polychlorinated biphenyls in different niches of rice paddy fields

The biotransformation of PCBs in three niches with contrasting redox conditions (water–soil interface, rhizosphere and non-rhizosphere subsoil) was studied using rhizoboxes subjected to the sequential flooding and draining conditions associated with rice cultivation in paddy fields. Rice cultivation favored PCB dechlorination and further transformation of the degradation products. Microbial dechlorination activity not only began earlier but was also 50% greater in the rhizosphere in comparison with bulk soil. Distinct profiles of both phospholipid fatty acids (PLFAs) and PCB congeners arose in each niche. Signature PLFAs attributed to Gram-positive (G+) bacteria were significantly correlated with the dissipation of PCB congeners in paddy field soils, especially in the rhizosphere.

Polychlorinated biphenyls and selected organochlorine pesticides in serum of Slovak population from industrial and non-industrial areas.

The concentrations of indicator polychlorinated biphenyls (PCBs No. 28, 52, 101, 138, 153 and 180) and organochlorine pesticides (HCB, p,p'-DDE and p,p'-DDT) in 121 blood serum specimens collected from non-occupationally exposed adults living in contaminated and comparison areas were determined using high-resolution gas chromatography/electron capture detection (HRGC/ECD). The sum of the serum concentrations of the three most abundant PCB congeners (No. 138, 153 and 180) found in participants (N = 81) living in industrial areas near incinerators, metallurgical and chemical plants (Krompachy, Kosice, Nemecka and Sala) was significantly higher (p < 0.001) than in participants living in villages and towns without known sources causing persistent organic pollutant (POP) contamination (N = 40). Similarly, significant differences were observed for p,p'-DDE (p < 0.0001) and p,p'-DDT (p < 0.002). However, a Mann-Whitney U test between groups showed that the difference for HCB was not statistically significant (p = 0.089). Age was positively correlated with the sum of PCBs (No. 138, 153 and 180), HCB and the sum of p,p'-DDE and p,p'-DDT (p < 0.01 for all).

Pcbs in Soils around an Old Electric Transformer Factory in North China

The 28 surface soil samples (0-10 cm) were collected from the urban area of Baoding city nearby an old electric transformer factory for analysis of 84 PCB congeners. Total PCBs concentrations ranged from 0.69 to 11.15 ng/g (mean: 3.62 ng/g). The PCBs concentration (5.72 ng/g) for sampling sites in the vicinity (0-2.5 km) of the transformer factory was higher than that (2.96 ng/g) for other sampling sites. Compositional patterns of individual congener and homologs were similar to those of Chinese transformer oils. The top five congeners were PCB-6, 18, 22, 33 and 31/28 among the identified PCBs. Low chlorinated PCBs (di-to tetra-CBs) accounted for 69.58% of total PCBs concentrations and the predominant PCB homologs were tri-CBs (46.38%), penta-CBs (13.73%) and di-CBs (9.47%), respectively. Principal component analysis showed that technical formulations such as Chinese transformer oil, Aroclor1242, 1016, KC-300 and A-30 were the main sources of soils PCBs from Baoding city. The TEQ concentrations based on ten dioxin-like PCBs ranged from 0 to 26.0986 ng/kg with the mean value as 7.3336 ng/kg.

PCBs in Air from an Industrial Zone in a Coastal City-Tianjin, China

The 23 air samples were collected from Tianjin Dongli industrial zone from July 2010 to May 2011 for the analysis of 84 PCB congeners to investigate the gas/particle partitioning. The total PCBs concentration ranged from 71.08 to 567.36 pg m-3 with the mean value as 307.78±137.45 pg m-3 and the seasonal trends were summer &gt;winter &gt;spring &gt;autumn. Gas PCBs accounted for 77.47% of the total PCBs. The fraction of each gas PCB homolog increased with the decreasing chlorine atoms. The contribution of gas PCBs to total PCBs showed a strong seasonal variation with summer (92.44%)&gt; autumn (85.16%) &gt; spring (80.61%) &gt; winter (42.70%). Tri-, tetra-, penta-PCBs and di-PCBs were the predominantly homologs in atmosphere from industrial zone in Tianjin. The natural logarithm of partial pressure of PCBs were well correlated with the inverse absolute environmental temperature (R=0.77). The steep slope of-3764 obtained from Clausius–Clapeyron plot indicated the influence of local PCBs sources.

Bacterial degradation of Aroclor 1242 in the mycorrhizosphere soils of zucchini (Cucurbita pepo L.) inoculated with arbuscular mycorrhizal fungi.

A greenhouse experiment was conducted to investigate the effects of zucchini (Cucurbita pepo L.), inoculated with the arbuscular mycorrhizal (AM) species Acaulospora laevis, Glomus caledonium, and Glomus mosseae, on the soil bacterial community responsible for Aroclor 1242 dissipation. The dissipation rates of Aroclor 1242 and soil bacteria abundance were much higher with the A. laevis and G. mosseae treatments compared to the non-mycorrhizal control. The biphenyl dioxygenase (bphA) and Rhodococcus-like 2,3-dihydroxybiphenyl dioxygenase (bphC) genes were more abundant in AM inoculated soils, suggesting that the bphA and Rhodococcus-like bphC pathways play an important role in Aroclor 1242 dissipation in the mycorrhizosphere. The soil bacterial communities were dominated by classes Betaproteobacteria and Actinobacteria, while the relative proportion of Actinobacteria was significantly (F=2.288, P<0.05) correlated with the PCB congener profile in bulk soil. Our results showed that AM fungi could enhance PCB dissipation by stimulating bph gene abundance and the growth of specific bacterial groups.

Assessment of DDT, HCH and PCB pollution of lake sediments in Poland

Abstract In the years 2010-2013, 528 samples of surface sediments were collected from lake depths in the area of Poland. The content of 7 PCB congeners, HCH isomers and p,p’-DDT, p,p’-DDE and p,p’-DDD was determined using the GC-ECD method. The studies showed the common occurrence of organochlorine compounds in lake sediments in Poland. The presence of HCHs, at a concentration above the determination limit, was detected in 83.71% of samples, that of DDTs in 98.86% of samples, and of PCBs in 98.86% of samples. The maximum HCH concentration was 60.7 ng g-1, that of DDTs 602.9 ng g-1, and of PCBs 50.7 ng g-1, while the averages were 6.3 ng g-1, 19.2 ng g-1 and 2.8 ng g-1, respectively. High levels of DDTs are found in sediments of those lakes upon which major towns are located, whereas the highest HCH concentrations are observed in sediments of the lakes upon which holiday centres and agrotourism facilities have developed. The ratio of concentrations of total DDT metabolites to p,p’-DDT was above 2 in almost all samples, and the value was most frequently from several to tens (average 28.3). Sediments of some lakes contain higher concentrations of γ-HCH and DDT metabolites than their PEC values, the content of γ-HCH was higher in 1.89% of the analysed samples, the content of p,p’-DDE in 3.78% of the samples, and the content of p,p’-DDD in 7.38% of the samples. Concentrations of p,p’-DDT and PCB in excess of the PEC value were not found in any of the samples tested.

Distribution and bioaccumulation of polychlorinated biphenyls and organochlorine pesticides residues in sediments and Manila clams (Ruditapes philippinarum) from along the Mid-Western coast of Korea

The distribution and bioaccumulation features of PCBs, DDTs, and HCHs were investigated in the sediments and Manila clams collected from along the Mid-Western coast of Korea. The measured concentrations of ΣPCBs, ΣDDTs and ΣHCHs were 1.08–3.5, 0.12–0.35 and 0.090–0.30ngg−1dw in sediment, and 33–390, 7.4–46 and 6.3–27ngg−1 lipid in Manila clam, respectively. Their levels were found to be relatively lower than those of other contaminated areas and the consumption of Manila clam from these areas seems to be safe for human health according to calculated lifetime cancer risk and hazard indices. The ΣPCBs and ΣDDTs concentrations in sediments showed a significant relationship to those in clams. The significant correlation was observed between BSAF in clams and Kow for each PCB congeners and DDT metabolites. These findings support that the PCBs and DDTs levels, which are highly hydrophobic chemicals, in clam reflect the sediment pollution through bioaccumulation.

Composition and leaching of construction and demolition waste: Inorganic elements and organic compounds

Thirty-three samples of construction and demolition waste collected at 11 recycling facilities in Denmark were characterised in terms of total content and leaching of inorganic elements and presence of the persistent organic pollutants PCBs and PAHs. Samples included (i) “clean” (i.e. unmixed) concrete waste, (ii) mixed masonry and concrete, (iii) asphalt and (iv) freshly cast concrete cores; both old and newly generated construction and demolition waste was included. PCBs and PAHs were detected in all samples, generally in non-critical concentrations. Overall, PAHs were comparable to background levels in urban environments. “Old” and “new” concrete samples indicated different PCB congener profiles and the presence of PCB even in new concrete suggested that background levels in raw materials may be an issue. Significant variability in total content of trace elements, even more pronounced for leaching, was observed indicating that the number of analysed samples may be critical in relation to decisions regarding management and utilisation of the materials. Higher leaching of chromium, sulphate and chloride were observed for masonry-containing and partly carbonated samples, indicating that source segregation and management practices may be important. Generally, leaching was in compliance with available leaching limits, except for selenium, and in some cases chromium, sulphate and antimony.