Polychlorinated Biphenyls Mass Research Articles

Unexpectedly high levels and health risks of atmospheric polychlorinated biphenyls in modern mechanical dismantling of obsolete electrical equipment: investigations in a large integrated e-waste dismantling industrial estate

Large industrial estates for electrical and electronic waste (e-waste) mechanical dismantling and recycling are gradually replacing outmoded small factories and intensive domestic workshops for e-waste manual and chemical dismantling. However, the air pollution and health risks of persistent organic pollutants during the modern mechanical processing of e-waste, especially obsolete electrical equipment, still remain unclear. Here, unexpectedly high levels (409.3 ng/m3) and health risks of airborne polychlorinated biphenyls (PCBs) were found during the mechanical processing of obsolete electric equipment or parts in a large integrated dismantling industrial estate, which is comparable to or a dozen times higher than those reported during chemical processing. In contrast, the levels (936.0 pg/m3) and health risks of particulate polybrominated diphenyl ethers (PBDEs) were all lower than those of previous studies. PCB emissions (44.9–3300.5 ng/m3) varied significantly across six mechanical dismantling places specifically treating waste motors, electrical appliances, hardware, transformers, and metals, respectively. The high PCB content and mass processing number of obsolete electrical equipment probably result in the highest PCB emissions from the mechanical dismantling of obsolete motors, followed by waste electrical appliances and metals. The PCB non-cancer and cancer risks associated with inhalation and dermal exposure in different mechanical dismantling places were all above the given potential risk limits. In particular, the health risks of dismantling obsolete motor exceeded the definite risk levels. Little difference in PCB emissions and health risks between working and non-working time suggested the importance of PCB volatilization from most e-waste. Such high PCB emissions and health risks of PCBs undoubtedly posed a severe threat to frontline workers, but fortunately, they decreased significantly with the increasing distance from the industrial estate. We highlight that PCB emissions and associated health risks from obsolete electrical equipment with high PCB content during mechanical dismantling activities should be of great concern.

Short-chain fatty acids facilitated long-term dechlorination of PCBs in Taihu Lake sediment microcosms: Evidence from PCB congener and microbial community analyses

Microbial reductive dechlorination hosts great promise as an in situ bioremediation strategy for polychlorinated biphenyls (PCBs) contamination. However, the slow dechlorination in sediments limits natural attenuation. Short-chain fatty acids, as preferred carbon sources and electron donors for dechlorinating microorganisms, might stimulate PCB dechlorination. Herein, two sets of short-chain fatty acids, sole acetate and a fatty acid mixture (acetate, propionate, and butyrate), were amended periodically into Taihu Lake (China) sediment microcosms containing nine PCB congeners (PCB5, 12, 64, 71, 105, 114, 149, 153, and 170) after 24 weeks of incubation. Short-chain fatty acids facilitated the long-term PCB dechlorination and the promoting effect of the fatty acid mixture compared favorably with that of sole acetate. By the end of 108 weeks, the total PCB mass concentrations in acetate amended and fatty acid mixture amended microcosms significantly declined by 7.6% and 10.3% compared with non-amended microcosms (P < 0.05), respectively. Short-chain fatty acids selectively favored the removal of flanked meta and single-flanked para chlorines. Notably, a rare ortho dechlorination pathway, PCB25 (24-3-CB) to PCB13 (3-4-CB), was enhanced. Supplementary fatty acids significantly increased reductive dehalogenases (RDase) gene pcbA5 instead of improving the growth of Dehalococcoides. These findings highlight the merits of low cost short-chain fatty acids on in situ biostimulation in treating PCBs contamination.

Mapping the Contribution of Biomass Burning to Persistent Organic Pollutants in the Air of the Indo-China Peninsula Based on a Passive Air Monitoring Network.

Biomass burning (BB) is an important source of atmospheric persistent organic pollutants (POPs) across the world. However, there are few field-based regional studies regarding the POPs released from BB. Due to the current limitations of emission factors and satellites, the contribution of BB to airborne POPs is still not well understood. In this study, with the simultaneous monitoring of BB biomarkers and POPs based on polyurethane foam-based passive air sampling technique, we mapped the contribution of BB to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Indo-China Peninsula. Spearman correlations between levoglucosan and 16 PCBs (rs = 0.264-0.767, p < 0.05) and 2 OCPs (rs = 0.250-0.328, p < 0.05) confirmed that BB may facilitate POP emissions. Source apportionment indicated that BB contributed 9.3% to the total PCB and OCP mass. The high contribution of positive matrix factorization-resolved BB to PCBs and OCPs was almost consistent with their concentration distributions in the open BB season but not completely consistent with those in the pre-monsoon and/or monsoon seasons. Their contribution distributions may reflect the use history and geographic distribution in secondary sources of POPs. The field-based contribution dataset of BB to POPs is significant in improving regional BB emission inventories and model prediction.

Lab-scale biodegradation assay using passive samplers to determine microorganisms’ ability to reduce polychlorinated biphenyl (PCB) volatilization from contaminated sediment

Many PCB-degrading aerobes have been identified which may serve as bioaugmentation strains for aerobic, in situ bioremediation or in combination with dredging operations. The present work describes a lab-scale PCB biodegradation assay which can be used to screen potential bioaugmentation strains or consortia for their ability to decrease PCB mass flux from contaminated sediment to air through biodegradation of freely dissolved PCBs that have desorbed from sediment particles. The assay uses two types of passive samplers to simultaneously measure PCB mass that is freely dissolved in aqueous solution and PCB mass that has volatilized to the headspace of the bioreactor. Using this approach, relative comparisons of PCB mass accumulated in passive samplers between bioaugmented treatments and controls allow for practical assessment of a microbial strain's ability to reduce both freely dissolved and vapor phase PCB concentrations. The method is designed to be conducted using aliquots of homogenized, well-characterized, PCB-contaminated sediment gathered from a field site. This work details the experimental design methodology, required materials, bioreactor set-up, passive sampling, PCB-extraction, sample cleanup, and quantification protocols such that the biodegradation assay can be conducted or replicated. A step-by-step protocol is also included and annotated with photos, tips, and tricks from experienced analysts.•Relative comparisons of PCB mass accumulated in passive samplers between experimental treatments and controls allow for practical assessment of bioaugmentation strain's ability to reduce both freely dissolved and vapor phase PCB concentrations•Passive sampler preparation, deployment, PCB-extraction, cleanup procedures, and quantification are detailed step-by-step and annotated by experienced analysts

Sources of polychlorinated biphenyls to Upper Hudson River fish post-dredging

Polychlorinated biphenyls (PCBs) are persistent, bioaccumulative, and toxic chemicals that are the dominant contaminant in the Upper Hudson River (UHR) in New York State where two General Electric (GE) plants historically discharged PCBs to the river. Portions of the UHR were dredged from 2009 to 2015 to address PCB contamination. In 2017, the first post-dredging survey of yearling feeder fish and sediment PCB contamination was conducted to establish a baseline for the recovery of the river. Prior analysis of the sediment data from the 2017 survey indicated that ∼2% of the PCBs in the surface sediment were higher in molecular weight than the formulation used by GE and therefore arose from non-GE sources. In this work, the fish PCB data from the 2017 survey were analyzed using Positive Matrix Factorization (PMF). Empirical Bayesian Kriging (EBK) was used to estimate PCB concentrations in the sediment at the locations where fish were collected. The results suggest that PCBs that are the products of microbial dechlorination bioaccumulate in the fish and represent 7% of the PCB mass in the fish data set. Further, the results suggest that about 13% of the PCBs in the fish may have come from non-GE sources. This is higher than the percentage of non-GE PCBs in the sediment, but can be explained by the higher molecular weight of the non-GE mixture which causes it to bioaccumulate more effectively than GE PCBs. Concentrations of the non-GE PCBs averaged about 240 ppb wet weight (whole body) in yearling feeder fish. The remedial goals range from 50 to 400 ppb ww in fillet for fish including piscivorous species that are likely to have higher PCB concentrations than feeder fish.

Aerobic Bioaugmentation to Decrease Polychlorinated Biphenyl (PCB) Emissions from Contaminated Sediments to Air.

We conducted experiments to determine whether bioaugmentation with aerobic, polychlorinated biphenyl (PCB)-degrading microorganisms can mitigate polychlorinated biphenyl (PCB) emissions from contaminated sediment to air. Paraburkholderia xenovorans strain LB400 was added to bioreactors containing PCB-contaminated site sediment. PCB mass in both the headspace and aqueous bioreactor compartments was measured using passive samplers over 35 days. Time-series measurements of all 209 PCB congeners revealed a 57% decrease in total PCB mass accumulated in the vapor phase of bioaugmented treatments relative to non-bioaugmented controls, on average. A comparative congener-specific analysis revealed preferential biodegradation of lower-chlorinated PCBs (LC-PCBs) by LB400. Release of the most abundant congener (PCB 4 [2,2′-dichlorobiphenyl]) decreased by over 90%. Simulations with a PCB reactive transport model closely aligned with experimental observations. We also evaluated the effect of the phytogenic biosurfactant, saponin, on PCB bioavailability and biodegradation by LB400. Time-series qPCR measurements of biphenyl dioxygenase (bphA) genes showed that saponin better maintained bphA abundance, compared to the saponin-free treatment. These findings indicate that an active population of bioaugmented, aerobic PCB-degrading microorganisms can effectively lower PCB emissions and may therefore contribute to minimizing PCB inhalation exposure in communities surrounding PCB-contaminated sites.

Persistent Problem: Global Challenges to Managing PCBs

Polychlorinated biphenyls (PCBs), “famous” as persistent organic pollutants (POPs), have been managed nationally since the 1970s and globally under the Stockholm Convention on POPs since 2004, requiring environmentally sound management (ESM) of PCBs by 2028. At most, 30% of countries are on track to achieve ESM by 2028. Globally over 10 million tonnes of PCB-containing materials remain, mostly in countries lacking the ability to manage PCB waste. Canada (Ontario) and Czechia, both parties to the Stockholm Convention, are close to achieving the 2028 goal, having reduced their stocks of pure PCBs by 99% in the past 10 years. In contrast, the USA, not a party to the Stockholm Convention, continues to have a substantial but poorly inventoried stock of PCBs and only ∼3% decrease in mass of PCBs since 2006. PCB management, which depends on Stockholm Convention support and national compliance, portends major challenges for POP management. The failure to manage global PCB stocks >30 years after the end of production highlights the urgent need to prioritize reducing production and use of newer, more widely distributed POPs such as chlorinated paraffins and per- and polyfluorinated alkyl substances, as these management challenges are unlikely to be resolved in the coming decades.

Analysis of Volumes and Sources of Waste Containing Persistent Organic Pollutants on the Territory of Odesa Region

Purpose. The estimating the amount of accumulation of waste containing Persistent Organic Pollutants (POPs) and state of the management system for this waste in Odesa region. Methods. To calculate the amount of POPs inflows into the environment, we use an updated European methodology for the inventory of pollutant emissions «EMEP/EEA air pollutant emission inventory guidebook (2019) ». Results. The priority sources of waste accumulation containing polychlorinated biphenyls (PCBs) in Odesa region are identified and analyzed; the availability and state of programs implementation for the detoxification of unusable РOPs-containing pesticides in the Odesa region is estimated; specific masses of POPs-containing pesticides per capita in each districts are determined; according to the value of specific masses of pesticides, priority districts for organization of measures to detoxify POPs-containing pesticides are arranged and identified; using the updated European methodology, the volumes of PCB leaks from PCB-containing equipment and the volumes of PCB inflows into the environment (soil cover and air basin) are calculated; the results are ranked and priority districts for detoxification of PCB-containing equipment and, as a result, effective implementation of the Stockholm Convention are identified.The largest share of pesticides falls on the residents of Savran (2,660 kg/person), Biliaivka (2.47 kg/person), Kodyma (2,082 kg/person) and Liubashivka (1,197 kg/person) districts, which should become a priority in the program for detoxification of unusable POPs-containing pesticides. Conclusions. The existing legal base and methodological framework is not enough to effectively implement the requirements of the Stockholm Convention. The program for the detoxification of unusable POPs-containing pesticides for 2018 has not been implemented. So pesticides that are stored incorrectly in the vast majority of cases, are a probable source of PCBs for residents in which districts pesticides are localized The largest contribution to the supply of PCBs from electrical equipment falls on Odesa – 49.2% of the total PCBs mass coming into the environment from this source. That is why the implementation of the program for the discontinuance of using equipment containing PCBs in Odesa region must begin from Odesa.

Leaching Rate of Polychlorinated Biphenyls (PCBs) from Marine Paint Chips

Polychlorinated biphenyls (PCBs) were added to certain marine vessel bottom paints as a plasticizer to improve the adhesion and durability of the paint. The most common PCB formulation used to amend such paints was Aroclor 1254. Fugitive Aroclor-containing paint chips generated from vessel maintenance and repair operations represent a potential source of PCB contamination to sediments. Limited published studies indicate that Aroclor-containing paint is largely inert and exhibits low PCB leaching into water; however, the rate and degree of leaching of PCBs from paint chips have not been directly studied. This laboratory-based study evaluated the rate and extent of leaching of PCBs from paint chips into freshwater. The results of this investigation demonstrate that the rate of PCB dissolution from paint chips decreased rapidly and exponentially over time. Based on this study, it is estimated that the rate of leaching of PCBs from paint chips would cease after approximately 3 years of exposure to water. When all leachable PCBs were exhausted, it is estimated that less than 1% of the mass of PCBs in the paint chips was amenable to dissolution. The results of this experiment suggest that Aroclor-containing paint chips found in sediments are likely short-term sources of dissolved-phase PCB to pore or surface waters and that the majority of the PCBs in paint chips remain in the paint matrix and unavailable for partitioning into water.Graphic

Quantitative analysis of 209 polychlorinated biphenyl (PCB) congeners in sediments of the Raritan River estuary, USA

Abstract This study investigated the distribution of 209 polychlorinated biphenyl (PCB) congeners in sediment samples collected from seven sites in the Raritan River estuary (NJ, USA) using gas chromatography/tandem quadrupole mass spectrometry (GC/MS/MS). Results showed that concentrations of 209 PCB congeners ranged up to 20 ng/g, that total PCB concentrations by homolog groups varied from 9.0 to 327 ng/g, and that total PCB mass ranged from 101.0 to 1,476.3 ng with the order of sites 6 &amp;gt; 7 &amp;gt; 3 &amp;gt; 4 &amp;gt; 2 &amp;gt; 1 &amp;gt; 5. Furthermore, higher PCB concentrations were detected for homolog groups including hexa- and hepta-PCBs. More PCBs were associated with sediments at downstream sites possibly due to accumulation and deposition in the estuary, as supported by strong correlations of PCB concentrations between different sampling sites (R2 ≤ 0.96). Comparisons with prior reports showed that all total PCB concentrations were below those reported by the Contamination Assessment and Reduction Project (CARP) and Delaware River Basin Commission (DRBC), except for sites 6 and 7. Sites 3 and 4 had PCB concentrations exceeding the 22.7 ng/g limit of the Sediment Quality Guidelines (SQGs), whereas sites 6 and 7 exceeded the 180 ng/g limit, indicating potential health hazards from PCBs.

Sources of polychlorinated biphenyls to Upper Hudson River sediment post-dredging

The Upper Hudson River (UHR) has been contaminated with polychlorinated biphenyls (PCBs) since the 1940s due to the manufacture of capacitors at two plants near Hudson Falls and Fort Edward, NY by General Electric (GE). Dredging of portions of the UHR was conducted from 2009 to 2015 as a partial remedy for this contamination. In 2017, the New York State Department of Environmental Conservation undertook a comprehensive post-dredging survey of sediment contamination in the UHR. Thousands of samples were collected, and 130 of these were analyzed for PCBs using EPA method 1668A. This data set was analyzed using Positive Matrix Factorization. Six factors were observed. One factor resembled the dominant Aroclors used by GE with little alteration. Three factors represented different pathways and/or extents of microbial dechlorination. One factor resembled a mixture of microbial dechlorination products and a higher molecular weight Aroclor used by GE. The congener patterns of the dechlorination factors suggest that removal of chlorines at the ortho position does occur in the UHR sediment, in agreement with several laboratory studies showing that such ortho dechlorination is possible. This ortho dechlorination could theoretically lead to complete dechlorination of PCBs to biphenyl in UHR sediment. Only one factor was not attributable to GE. It represents inputs of PCBs from tributaries and urban areas and explains 1.7% of the PCB mass in the sediments. The small contribution from the non-GE PCB source suggests that recontamination of the sediment after dredging was minor.

Polychlorinated biphenyls in stormwater sediments: Relationships with land use and particle characteristics

Polychlorinated biphenyls (PCBs) are classified as persistent organic pollutants (POPs). Concentrations of 209 PCB congeners as well as profiles of the ten homologues were determined in stormwater sediments collected from various (primarily roadway) sites with different land use. The total PCB concentrations ranged from 8.3 to 57.4 ng/g dry weight (dw), with a mean value of 29.2 ng/g dw. PCB concentrations varied with nearby land use. Higher stormwater sediment PCB concentrations were found in dense urban areas (average: 39.8 ± 10.5 ng/g) and residential areas (average: 35.3 ± 6.2 ng/g) compared to highways passing through greenspace (average: 18.0 ± 0.4 ng/g). The number of chlorines per biphenyl ranged from 3.63 to 5.39 and the toxic equivalency (TEQs) of the PCBs were between 1.5 and 18.0 pg/g at all sites. A non-Aroclor congener, PCB 11, was detected in all samples and was dominant at two sites. PCBs were sorbed to smaller stormwater particulate matter (≤75 μm) at higher concentrations compared to larger particles (>75 μm). PCB sorption tended to increase with the total organic carbon (TOC) of the particulate matter in the sediment samples. However, greater PCB mass (almost 80%) was present in the larger particles. Information on sediment PCB concentrations from different land uses, along with stormwater particulate matter data can allow the estimation of PCB loads and load reductions using stormwater control measures.

Estimating the Mass of Chemicals Associated with Ocean Plastic Pollution to Inform Mitigation Efforts.

Plastic pollution in the marine environment is well documented. What remains less recognized and understood are the chemicals associated with it. Plastics enter the ocean with unreacted monomers, oligomers, and additives, which can leach over time. Moreover, plastics sorb organic and inorganic chemicals from surrounding seawater, for example, polychlorinated biphenyls (PCBs) and metals. Thus, interception and cleanup of plastics reduces the amount of chemical contaminants entering or reentering the oceans and removes those already present. Here, we estimate 1) the mass of selected chemical additives entering the global oceans with common plastic debris items, and 2) the mass of sorbed chemicals (using PCBs as a case study) associated with microplastics in selected locations. We estimate the mass of additives that entered the oceans in 2015 as constituents of 7 common plastic debris items (bottles, bottle caps, expanded polystyrene (EPS) containers, cutlery, grocery bags, food wrappers, and straws or stirrers). We calculate that approximately 190 tonnes (t) of 20 chemical additives entered the oceans with these items in 2015. We also estimate the mass of PCBs associated with microplastics in 2 coastal (Hong Kong and Hawaii) and 2 open ocean (North Pacific and South Atlantic gyres) locations, as comparative case studies. We find that the mass of chemicals is related to the mass of plastics in a location, with greater mass of PCBs closer to the source (i.e., land), where there is more plastic per unit area compared to the open ocean. We estimate approximately 85 000 times more PCBs associated with plastics in an average 4.5-km stretch of beach in Hong Kong than from the same size transect in the North Pacific gyre. In conclusion, continuing efforts for plastic interception and cleanup on shorelines effectively reduces the amount of plastic-related chemicals entering and/or reentering the marine environment. Integr Environ Assess Manag 2019;15:596-606. © 2019 SETAC.

Source Apportionment of Polychlorinated Biphenyls in Atmospheric Deposition in the Seattle, WA, USA Area Measured with Method 1668.

Atmospheric deposition can be an important pathway for the delivery of toxic polychlorinated biphenyls (PCBs) to ecosystems, especially in remote areas. Determining the sources of atmospheric PCBs can be difficult, because PCBs may travel long distances to reach the monitoring location, allowing for a variety of weathering processes that may alter PCB fingerprints. Previous efforts to determine the sources of atmospheric PCBs have been hampered by the electron capture detection methods used to measure PCBs. In this work, EPA method 1668, which is capable of measuring all 209 congeners, was used to measure PCBs in bulk atmospheric deposition at seven locations in the Green-Duwamish River watershed in and near Seattle, WA. Analysis of this data set via Positive Matrix Factorization allowed the identification of six factors that represent PCB sources. Four factors, representing approximately 88% of all PCB mass, are strikingly similar to unweathered Aroclors, suggesting minimal weathering during transport and/or local PCB sources at some sites. A fifth factor contained virtually all of the PCB 11 mass and represents PCBs from pigments. It explained approximately 39% of the Toxic Equivalency Quotient in the atmospheric deposition samples. The remaining factor contained non-Aroclor PCBs and may be related to silicone.

Occurrence of halogenated organic contaminants in estuarine sediments from a biosphere reserve in Southern Atlantic

The occurrence, distribution, and the total mass of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were studied in surficial sediments of the Paranaguá Estuarine System (PES), a subtropical estuary in Southern Atlantic. Altogether, concentrations and inventories of contaminants ranged from <0.06 to 4.78 ng g−1 and < 0.13 to 10.47 ng cm−2, respectively. OCPs presented the higher total mass (10.85 kg) and a decreasing trend from the inner estuary towards the adjoining shallow shelf. The occurrence of PCBs was restricted to sites nearby urban and industrial areas, which accumulated ~80% of the total mass of PCBs. Although the level of contamination is low, the results refer to recent years, which mean that the actual values could be greater if sediments from periods of higher usage were analyzed. This study provides the first estimates of POPs (persistent organic pollutants) total mass in the PES, contributing to data for the Southern American inventories.

Modeling the impact of biota on polychlorinated biphenyls (PCBs) fate and transport in Lake Ontario using a population-based multi-compartment fugacity approach

Organisms have long been treated as receptors in exposure studies of polychlorinated biphenyls (PCBs) and other persistent organic pollutants (POPs). The influences of environmental pollution on organisms are well recognized. However, the impact of biota on PCB transport in an environmental system has not been considered in sufficient detail. In this study, a population-based multi-compartment fugacity model is developed by reconfiguring the organisms as populated compartments and reconstructing all the exchange processes between the organism compartments and environmental compartments, especially the previously ignored feedback routes from biota to the environment. We evaluate the model performance by simulating the PCB concentration distribution in Lake Ontario using published loading records. The lake system is divided into three environment compartments (air, water, and sediment) and several organism groups according to the dominant local biotic species. The comparison indicates that the simulated results are well-matched by a list of published field measurements from different years. We identify a new process, called Facilitated Biotic Intermedia Transport (FBIT), to describe the enhanced pollution transport that occurs between environmental media and organisms. As the hydrophobicity of PCB congener increases, the organism population exerts greater influence on PCB mass flows. In a high biomass scenario, the model simulation indicates significant FBIT effects and biotic storage effects with hydrophobic PCB congeners, which also lead to significant shifts in systemic contaminant exchange rates between organisms and the environment.

Assimilation efficiency of sediment-bound PCBs ingested by fish impacted by strong sorption.

Uptake of polychlorinated biphenyls (PCBs) by fish is controlled by the bioavailability of ingested PCBs in the gut and the freely dissolved concentration in the water moving across the gills. The prediction of bioaccumulation in fish relies on models that account for these exposure routes; however, these models typically do not account for incidental ingestion of sediment by fish, which is not well studied. The literature values for the PCB assimilation efficiency in the gut have been reported for compounds in food matrices and not associated with sediment particles. It is also unclear how mitigation strategies that alter PCB bioavailability in sediments affect predictions made by the bioaccumulation models when sediment ingestion is involved. To test the bioavailability of PCBs from treated and untreated sediments, dietary assimilation efficiencies were measured for 16 PCB congeners in mummichogs (Fundulus heteroclitus) that were fed 4 experimental diets. Diets consisted of PCB-spiked earthworms, spiked untreated sediment mixed with earthworms, spiked activated carbon-treated sediment mixed with earthworms, and spiked activated carbon mixed with earthworms. Assimilation efficiencies were determined by calculating the ratio of PCB mass in the fish tissue to the PCB mass in the food after a pulse feeding experiment. Assimilation efficiencies of PCBs associated with earthworm diet were similar to the values reported in the literature. Fish that were fed the PCB-spiked untreated sediment and activated carbon particles exhibited the highest and lowest assimilation efficiencies, respectively, over a wide KOW range. Assimilation efficiencies of sediment-bound PCBs were significantly reduced (31-93% reduction for different congeners) after amendment with activated carbon. The present study indicates that assimilation of PCBs can be reduced by sorption to black carbon. Environ Toxicol Chem 2017;36:3480-3488. © 2017 SETAC.

Atmospheric occurrence, transport and gas–particle partitioning of polychlorinated biphenyls over the northwestern Pacific Ocean

Ship-board air samples were collected during March to May 2015 from the East China Sea (ECS) to the northwestern Pacific Ocean (NWP) to explore the atmospheric occurrence and gas–particle partitioning of polychlorinated biphenyls (PCBs) when the westerly East Asian Monsoon prevailed. Total PCB concentrations in the atmosphere ranged from 56.8 to 261 pg m−3. Higher PCB levels were observed off the coast and minor temperature-induced changes showed that continuous emissions from East Asia remain as an important source to the regional atmosphere. A significant relationship between Koa (octanol–air partition coefficient) and KP (gas–particle partition coefficient) for PCBs was observed under continental air masses, suggesting that land-derived organic aerosols affected the PCB gas–particle partitioning after long-range transport, while an absence of this correlation was identified in marine air masses. The PCB partitioning cannot be fully explained by the absorptive mechanism as the predicted KP were found to be 2–3 orders of magnitude lower than the measured Kp, while the prediction was closely matched when soot adsorption was considered. The results suggested the importance of soot carbon as a transport medium for PCBs during their long-range transport and considerable impacts of continental outflows on PCBs across the downwind area. The estimated transport mass of particulate PCBs into the ECS and NWP totals 2333 kg during the spring, constituting ca. 17% of annual emission inventories of unintentionally produced PCB in China.

Effects of sampling interval on the passive air sampling of atmospheric PCBs levels

ABSTRACTIn this study, we collected Polychlorinated biphenyls (PCBs) using passive air samplers (PASs), between February 4, 2013 and February 2, 2014, with the sampling periods ranging from 10 to 60 days. The samples were collected with PASs that contained polyurethane foam (PUF). With these samples, 87 PCB congeners were analyzed. Sampling coefficient (R) values for the four seasons were calculated using both the high volume air sampler (HVAS) and PAS samples collected with the same time interval. The average of the annual concentrations of 87 PCB congeners, calculated using the R values specific to this study, was 234 ± 175 pg/m3. PCB congeners with 3- and 4- chlorines were dominant. The samples were collected at the same time interval but at different times to represent accumulation in the PASs. The linear regression coefficients (r) of the PCB mass accumulated in PASs against time ranged from 0.89 and 0.97 indicating that accumulation was linear. Moreover, the concentrations of the PCB congeners were statistically correlated with atmospheric conditions.

Levels, Sources, and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Soils from Industrial Areas: A Case Study from Saudi Arabia

ABSTRACTThe objective of this study was to assess the pollution levels, sources, and human health risk of polychlorinated biphenyls (PCBs) in soils of industrial areas of the central and eastern regions of Saudi Arabia. Therefore, the surface soil samples from industrial areas (cement kiln, oil refinery, electric power plant, steel industry, and desalination plant) were collected and analyzed by High-Resolution Gas Chromatography-Mass Spectrometry/Mass Spectrometry-Time of Flight (HRGC-MS/MS-TOF) to quantify the levels of 26 PCBs (including 12 dioxin-like PCBs and 14 indicator-PCBs). The investigated 26 PCBs were detected in all soil samples. The total PCBs concentration (from tri-CBs to hepta-CBs) ranged from 171 to 4892 pg g−1 with an average of 1369 pg g−1 in soils of the central region and of 142–1231 pg g−1 with an average of 302 in soils of the eastern region, showing higher values at cement factory and/or oil refinery sites. Overall, the indicator-PCBs were the main congeners and contributed dominantly to the total mass of PCBs in comparison with the dioxin-like PCB congeners, with the most abundant for PCB-180 in the soil samples of the central region. Among individual dioxin-like PCBs, PCB-126 had the highest average value of the toxicity equivalence (TEQ). The TEQ values of ∑12dioxin-like PCBs did not exceed the Canadian soil quality guidelines of dioxin (4 pg TEQ g−1). Based on human health risk assessment via ingestion, dermal contact, and inhalation, low adverse effects of PCBs could be expected as indicated by lower values of cancer risk (≤10−6). The principal component analysis indicated that there is a different source of PCBs with similar or different PCB profiles.