Low Concentrations Of Polychlorinated Biphenyls Research Articles

The Interplay of Persistent Organic Pollutants and Mediterranean Diet in Association With the Risk of Gestational Diabetes Mellitus.

Certain foods characterizing the alternate Mediterranean diet (aMED) are high in persistent organic pollutants (POPs), which are related to greater gestational diabetes mellitus (GDM) risk. We examined the associations of combined aMED and POP exposure with GDM. aMED score of 1,572 pregnant women was derived from food frequency questionnaires at early pregnancy within the U.S. Fetal Growth Study and plasma concentrations of 76 POPs, including organochlorine pesticides, polybrominated diphenyl ethers, polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances, were measured. Associations of combined aMED score and exposure to POPs with GDM risk were examined by multivariable logistic regression models. In 61 of 1,572 (3.88%) women with GDM, 25 of 53 included POPs had a detection rate >50%. Higher POP levels appeared to diminish potential beneficial associations of aMED score with GDM risk, with the lowest GDM risk observed among women with both high aMED score and low POP concentrations. Specifically, adjusted log-odds ratios of GDM risk comparing women with low PCB and high aMED score with those with low aMED score and high PCB concentrations was -0.74 (95% CI -1.41, -0.07). Inverse associations were also observed among women with low aMED score and high TransNo_chlor, PCB182_187, PCB196_203, PCB199, and PCB206. These associations were more pronounced among women with overweight or obesity. Pregnant women who consumed a healthy Mediterranean diet but had a low exposure to POP concentrations had the lowest GDM risk. Future endeavors to promote a healthy diet to prevent GDM may consider concurrent POP exposure.

Seasonal Air–Sea Exchange Dynamics of Polychlorinated Biphenyls Over the East China Marginal Seas: The Role of Water Masses in a Complex Coastal–Ocean Current System

AbstractContinental marginal seas are key reservoirs of anthropogenic pollutants. Understanding the physical processes controlling the air–sea exchange dynamics of polychlorinated biphenyls (PCBs) in the continental margin seas is crucial to constrain the contribution of PCBs from land and rivers to the ocean; however, the transport and fate of PCBs, and their controlling factors of air–sea exchange in the continental marginal seas still remain poorly understood. Here, we collected atmospheric and surface water samples from the Yellow Sea (YS) and East China Sea (ECS) in summer 2018 and winter 2019, and examined the PCB concentrations. The PCB air–sea gas exchange fluxes showed higher net volatilization in winter, largely due to southward movement of the strengthened Yellow Sea Coastal Current and Yangtze River Diluted Water with high PCB concentrations. Both the dissolved PCB concentrations in seawater and wind speed were the primary factors influencing the PCB air–sea exchange fluxes in winter. By contrast, weak PCB volatilization fluxes occurred when the Taiwan Warm Current with low PCB concentrations dominated in the ECS in summer. In comparison, the accumulation and release of some PCB homologues caused by a green tide in the coastal YS could lead to increased volatilization flux in summer. Our results suggest the transfer of air–sea exchange dynamics of PCBs from a water concentration‐dominated pattern to an environmental parameter‐controlled one due to their decreased land‐based input, and highlight the impact of water mass‐triggered changes (environmental parameters and algal blooms) on the air–sea exchange behavior of PCBs in the continental marginal sea.

Effect of sorbate stereochemistry on the sorption/desorption of polychlorinated biphenyls between natural soil and an aqueous solution

ABSTRACT This study aimed to investigate the effect of various sorbate physicochemical properties on the transportation, distribution, fate, and bioavailability as well as remediation of selected hydrophobic organic pollutants in the environment. The natural soil collected from uMngeni River of KwaZulu-Natal province of South Africa and non-ortho and ortho-substituted polychlorinated biphenyls (PCBs) were used in this study. Soil physicochemical properties were characterized and batch studies were carried out to determine the co-effects of PCB stereochemistry and concentration. The results indicated that non-ortho compounds (PCB 77) sorbed more to the soil, (approximately 67%) compared to the di-ortho substituted congener (PCB 52) with 59.5% sorption of the same homolog. The effect of initial concentrations of both non-ortho and ortho-substituted PCBs revealed that low initial PCB concentrations were mostly favored for the sorption while sorption was generally low for ortho-substituted PCBs at high concentration. It is noted from this study that the stereochemistry of PCB congeners may play a critical role in influencing the pollution indices in the environment. Therefore, ortho-substituted congeners may likely be susceptible to aqueous solubility and may likely lead to less affinity to sorb to soil/sediment, and if sorbed have potential to re-suspend back to surface water or leach to the groundwater easily thus posing more risk to aquatic organisms.

River organisms as indicators of the distribution and sources of persistent organic pollutants in contrasting catchments

Persistent organic pollutants (POPs) continue to threaten aquatic organisms, but risk assessments are restricted by poor knowledge of the distribution and quantity of these substances in different biota. Assessments on aquatic invertebrates are particularly scarce. Here, we investigate variation in polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorines (OCs) in sediments, biofilms, macroinvertebrates and fish across rivers in South Wales (UK). Persistent PCB (−118, −153, −180) and PBDE congeners (BDE-47, -99, −100), and OCs (p,p’-dichlorodiphenyldichloroethylene [p,p’-DDE] and dieldrin [HEOD]) dominated the POPs detected, indicating links to historical emissions. Low concentrations of less persistent PBDEs, PCBs and OCs, however, suggest more contemporary sources. Concentrations of POPs were 2–22 times greater in fish than invertebrates, but their detection frequency (>90%) and concentrations (0–304 ng g−1 wet weight) were higher in these organisms than in sediments or biofilms (<10%; 0–12 ng g−1 wet weight). Invertebrates and fish also contained several PCB congeners (28, 52, 77 and 105) and p,p’-dichlorodiphenyltrichloroethane (p,p’-DDT) that were not detected in the environmental samples. Concentrations of PBDEs, PCBs and OCs differed among invertebrate taxa and feeding guilds. After controlling for significant variation among sample types and taxa, PBDEs were found to increase with urban land cover, while increased PCBs were associated with urban land cover and wastewater discharge. These data illustrate how body burdens of POPs across invertebrate and fish taxa provide valuable information on the spatial variation and likely sources of persistent pollutants in freshwater ecosystems. More work is required to resolve differences in POP contamination between taxonomic groups.

Effects of Maternal Reproductive Investment on Sex-Specific Pollutant Accumulation in Seabirds: A Meta-Analysis.

Avian egg production demands resources such as lipids and proteins. Relative egg size and mass varies across species, reflecting differences in maternal investment. This variability may affect the maternal transfer of anthropogenic pollutants including lipophilic polychlorinated biphenyls (PCBs) and protein-associated per- and polyfluoroalkyl substances (PFASs) and mercury (Hg). We conducted a meta-analysis on seabirds and investigated whether interspecies variation in maternal investment contributes toward skewed pollutant concentration ratios between males and females, as Cmale/Cfemale (80 studies). Overall concentrations of PCBs and perfluorooctanesulfonic acid (PFOS) were 1.6 and 1.3 times higher, respectively, in males than females, whereas mercury was similar between sexes. Few studies compared females and eggs ( n = 6), highlighting a knowledge gap. We found that an increasing maternal investment as a clutch-to-female mass ratio resulted in lower PCB concentrations in females than in males during the incubation period, but no sex-specific differences were observed for mercury and PFOS. Egg production is both a lipid dominated and protein-limited process. Females transfer lipophilic pollutants more easily to eggs, and to a higher degree with increasing maternal investment, but feeding ecology may be more important. Interspecies variation in maternal pollutant transfer may lead to negative effects scaling from an offspring to population level.

Gas chromatography determination of the levels of polychlorinated biphenyls (PCBs) in seawater and sediment in the Gulf of Aqaba

The levels of persistent organic pollutants, polychlorinated biphenyls (PCBs), were determined in seawater and marine sediments from different sites along the Jordanian coast of the Gulf of Aqaba. Concentrations of 7 PCBs, namely, PCB-28, PCB-52, PCB-101, PCB-118, PCB-138, PCB-153, and PCB-180, were determined. An automated Soxhlet (Soxtec) extraction method was used for extraction with hexane–acetone as a solvent, and a pre-washed multilayer silica gel column was used for the clean-up step. Samples were analyzed using capillary gas chromatography (GC) with an electron capture detector (ECD) and GC–mass spectrometry (GC–MS) for confirmation. The method's limits of detection (LOD) were determined to be from 0.40 to 1.53 ng/L and from 0.39 to 0.91 ng/g dry weight for seawater and sediment, respectively. Concentrations of PCBs in seawater and sediment samples from all sites were below the LOD. This study provides evidence that very low concentrations of PCBs (&lt;2 ng/g) were found in the water and sediments of the Jordanian coast of the Gulf of Aqaba. PCB concentrations measured in this study can be considered as a baseline for future monitoring and control of PCBs as requested by the Stockholm Convention.

Sex-specific alterations of lipid metabolism in zebrafish exposed to polychlorinated biphenyls

Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) mixtures exerting environmental health risk. In mammals, PCBs have been shown to disrupt metabolic state, especially lipid metabolism, and energy balance, but their effects on lipid metabolism in fish are largely unknown. The zebrafish were selected as model and both male and female adult zebrafish were exposed to different concentrations of PCBs at gradient concentrations of 0.2, 2.0 and 20.0 μg/L for 6 weeks. PCB exposure did not affect survival, but a significant inhibition of growth was observed in the males after exposure to 20.0 μg/L. The lower concentrations of 0.2 and 2.0 μg/L increased hepatic lipid accumulation to a greater extent in male fish, but the higher concentration of 20.0 μg/L did not cause significant fat accumulation in either male or female fish. In males, the expression of genes related to lipogenesis and lipid catabolism was upregulated in a concentration-dependent manner in the liver and visceral mass without liver and gonad; the effects of exposure on lipid metabolism-related genes in female fish were less pronounced. PCB exposure did not induce significant oxidative stress, but did upregulate the expression of stress- and apoptosis-related genes, mostly in male fish. The low concentrations of PCBs (0.2 μg/L and 2.0 μg/L) exerted sex-specific effects on zebrafish lipid metabolism, and male fish were more sensitive to the exposure. This study provides new mechanistic insights into the complex interactions between PCBs, lipid metabolism, and sex in zebrafish, and may contribute to a future systematic assessment of the effects of PCBs on aquatic ecosystems.

Organochlorine pesticides, polybrominated diphenyl ethers and polychlorinated biphenyls in surficial sediments of the Awash River Basin, Ethiopia.

This study was initiated to document information on the levels of sediment contamination with organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Moreover, it was intended to identify compounds which impose major ecological risks to aquatic organisms. Surficial sediments were collected from 46 locations within the streams and rivers of the Awash River Basin. In total 30 compounds were included in this study: 16 OCPs, 7 PCBs and 7 PBDEs. The total concentrations of OCPs, PCBs, and PBDEs ranged from 6.63 to 206.13 ng g-1- dry weight (dw), 0.85 to 26.56 ng g-1-dw and 3.71 to 18.95 ng g-1-dw respectively. Out of all the tested OCPs, heptachlor, heptachlor epoxide, p,p′-dichlorodiphenyltrichloroethane (p,p′-DDT) and β-hexachlorocyclohexane (β-HCH) were the most abundant in the study area. The ratio of (β-HCH/∑HCHs) indicated that HCHs were originally from earlier usage of HCH in the area whereas the ratio of (p,p’-DDT/p,p’-DDE) showed that the majority of DDT components were recently introduced into most of the sampling locations. Even though there were relatively low concentrations of PBDEs and PCBs across the sampling sites, substantial amounts of PCBs were observed in Addis Ababa City. According to the established ecological risk indices, p,p’-DDT and γ-HCH are the major concerns for potential adverse ecological impacts. This study provided the first comprehensive information on organohalogenated compounds’ (OCs’) occurrences, spatial distributions, and ecological risks in sediments of the Awash River Basin. Thus, the report will be very useful background information for further studies on sediment contamination with OCs’ in the region. It also adds important first-hand data to the field of fresh water ecology and provides useful empirical evidence for setting pollution control priorities for an ecologically important, yet largely understudied region.

Enhanced biochars can match activated carbon performance in sediments with high native bioavailability and low final porewater PCB concentrations

A bench scale study was conducted to evaluate the effectiveness of in situ amendments to reduce the bioavailability of pollutants in sediments from a site impacted with polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and cadmium. The amendments tested included fine and coarse coal-based activated carbons (AC), an enhanced pinewood derived biochar (EPB), organoclay, and coke dosed at 5% of sediment dry weight. Strong reductions in total PCB porewater concentrations were observed in sediments amended with the fine AC (94.9–99.5%) and EPB (99.6–99.8%). More modest reductions were observed for the coarse AC, organoclay, and coke. Strong reductions in porewater PCB concentrations were reflected in reductions in total PCB bioaccumulation in fresh water oligochaetes for both the fine AC (91.9–96.0%) and EPB (96.1–96.3%). Total PAH porewater concentrations were also greatly reduced by the fine AC (>96.1%) and EPB (>97.8%) treatments. EPB matched or slightly outperformed the fine AC throughout the study, despite sorption data indicating a much stronger affinity of PCBs for the fine AC. Modeling EPB and fine AC effectiveness on other sediments confirmed the high effectiveness of the EPB was due to the very low final porewater concentrations and differences in the native bioavailability between sediments. However, low bulk density and poor settling characteristics make biochars difficult to apply in an aquatic setting. Neither the EPB nor the fine AC amendments were able to significantly reduce Cd bioavailability.

Contaminants reduce male contribution to reproduction at the population scale

In many populations, males compete for mates and contribute to genetic diversity, but are assumed to have little impact on population growth rates and density, because one father is all that is necessary to fertilize a large number of eggs and sire a potential cohort. A factor affecting male reproductive output is exposure to contaminants that either disrupt endocrine function or mimic hormones. Polychlorinated biphenyls (PCBs) persist in aquatic ecosystems and may interfere with the reproductive contribution of male fish to populations. We quantified 28 PCB congeners in adult male bluegills across eight Illinois lakes. In spring 2011 and 2012, mature male bluegills from lakes with conspecifics with PCB whole‐body residues ranging from undetectable to high (2,000 ng/g dry mass total PCBs) were placed in experimental ponds with mature females containing no detectable PCB body residues and allowed to reproduce in spring under natural conditions. The presence of PCBs in fish had no effect on the presence of intersex or other gonadal deformities in adult males nor was gonad size, lipid concentration, and survival affected. Males with high PCBs were heavier than those from lakes with low PCB concentrations. The relative density of juvenile bluegills produced in ponds by fall, a fitness endpoint in this species, was negatively related to contaminant concentration in fathers. Contaminant exposure and other factors that affect male reproduction may not only suppress the relative contribution of males to genetic diversity, but also the overall density of cohorts within populations.

Spatio-temporal trends of PCBs in the Swedish freshwater environment 1981-2012.

Polychlorinated biphenyls (PCBs) have been monitored in perch (Perca fluviatilis), pike (Esox lucius), and Arctic char (Salvelinus alpinus) in reference lakes since the late 1960s. Temporal trends and spatial patterns are currently monitored in nine and 32 lakes, respectively. Overall, PCB concentrations are decreasing. However, this is not consistent for all congeners across all lakes and species. Perch has comparatively low PCB concentrations relative to suggested target levels, but individual congener concentrations in some lakes are concerningly high. No temporal trend is seen for CB-118 and CB-153 in perch, but significant decreasing trends exist for Arctic char and pike, for which monitoring started earlier than for perch. The lower/higher chlorinated congener ratio decreased over time in most lakes, indicating fewer new emissions. CB-118 and CB-153 concentrations in perch show spatial gradients across Sweden, with higher concentrations found near urban/industrial areas.

Levels, distribution and air–soil exchange fluxes of polychlorinated biphenyls (PCBs) in the environment of Punjab Province, Pakistan

An initial survey of the concentrations of polychlorinated biphenyl (PCB) compounds in air and soils across industrial and agricultural areas of Punjab Province, Pakistan, was conducted from January to March 2011. The total concentration of all PCBs (<Sigma>31 PCBs) ranged from 34 to 389pgm−3 in air and from 7 to 45ngg−1 dry weight in soils, where both ranges were similar to the average ranges in other areas of the world. PCBs were elevated across industrial regions near urban and industrial sources. Consistently low air concentrations of PCBs at the agricultural sites suggest that they are less widespread or uniformly distributed in the Pakistani atmosphere. The calculated air and soil fugacity fraction values indicated that soils are a potential secondary source of PCBs in agricultural areas, whereas they are in equilibrium or atmospheric deposition in industrial and urban areas. TEQ concentrations of dioxin-like PCBs for soil samples met the Canadian standard. However, local authorities should address the human health threats from urban and industrial soils in Punjab Province, Pakistan.

Current concentrations, temporal trends and determinants of persistent organic pollutants in breast milk of New Zealand women

Breast milk samples of 39 first time mothers aged 20–30 were collected in 2007–2010 from rural and urban areas of New Zealand, following the fourth World Health Organization coordinated survey protocol. Samples were individually analysed for persistent organic pollutants (POPs) including dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). The lipid adjusted concentrations of PCDD/Fs (mean toxic equivalent (TEQ): 3.54pg/g) and PCBs (mean TEQ 1.29pg/g) were low in comparison to those reported for other countries, and concentrations of dieldrin (10ng/g) and p,p′-DDE (379ng/g) and PBDEs were in the mid-range. Breast milk concentrations of PCDD/F-TEQ, PCB-TEQ, dieldrin and p,p′-DDE were significantly higher in rural compared to urban areas (+23%, 33%, 59%, and 44% respectively), while concentrations of several PBDEs and lindane were higher in urban areas. Concentrations of PCDD/Fs, PCBs and OCPs, but not PBDEs, increased with age, and higher body mass index was associated with lower concentrations of PCBs. Despite New Zealand's low body burdens of many chlorinated POPs in comparison to other countries, breast milk concentrations continued to decrease over time, with a decrease by half over the last 10years for PCDD/F-TEQ (−40%), PCB-TEQ (−54%) and OCPs −34 to −90%), indicating that regulatory measures continue to have beneficial effects. Continued monitoring is needed particularly for the brominated POPs for which little New Zealand specific data is available.

Sources and Temporal Patterns of Polychlorinated Biphenyls Around a Large South American Grain-Shipping Port (Paranaguá Estuarine System, Brazil)

The Paranaguá Estuarine System (PES) is an important estuarine environment on the Brazilian coast. The economic importance of the PES is mainly related to industries, fuel terminals, and the main South American grain-shipping port. The aim of this work was to determine the vertical distribution of polychlorinated biphenyls (PCBs) in three sediment cores from the PES. The methods included Soxhlet extraction, clean-up, and quantification by gas chromatography with electron capture detection. The concentrations of total PCBs ranged from lower than the detection limit to 6.65 ng g(-1). Low PCB concentrations were detected in P1 and P3, which were collected far away from direct human activities. In P2, the compositional pattern of PCB congeners showed greater concentrations of tetra- and penta-chlorinated congeners associated with urban and port activities near Paranaguá city. The differences in concentrations between the three sediment cores were attributed to the distance of the sampling points in relation to the possible sources of pollution, which are mostly related to Paranaguá city. The vertical distribution of PCBs in the sediment core P2 was related to historical anthropogenic activities. The highest PCB input was from 1970 to the early 1990s, which coincides with a period of greater use of PCBs in Brazil as well as their greater worldwide production.

Persistent Organic Pollutants in Juvenile Chinook Salmon in the Columbia River Basin: Implications for Stock Recovery

AbstractAmong the populations of Pacific salmon and steelhead Oncorhynchus mykiss (anadromous Rainbow Trout) that inhabit the Columbia River basin there are currently 13 Evolutionarily Significant Units listed as threatened or endangered under the U.S. Endangered Species Act. While habitat loss, dams, overharvest, and climate change have been implicated in declining abundance of Chinook Salmon O. tshawytscha in the Columbia River, chemical contaminants represent an additional, yet poorly understood, conservation threat. In this study we measured concentrations of persistent organic pollutants in juvenile Chinook Salmon from various Columbia River stocks and life history types to evaluate the potential for adverse effects in these threatened and endangered fish. Polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs), recognized contaminants of concern in the Columbia basin, are the primary focus of this paper; other contaminants found in these fish, such as polybrominated diphenyl ethers and polycyclic aromatic hydrocarbons, are described in other publications. We frequently detected PCBs and DDTs in juvenile salmon and salmon diet samples from the lower Columbia River and estuary. In some cases, concentrations in salmon were above estimated thresholds for effects on growth and survival. The tidal freshwater portion of the estuary, between Portland, Oregon, and Longview, Washington, appeared to be an important source of contaminants for juvenile salmon and a region in which salmon were exposed to toxicants associated with urban development and industrial activity. Highest concentrations of PCBs were found in fall Chinook Salmon stocks with subyearling life histories, including populations from the upper Columbia and Snake rivers, which feed and rear in the tidal freshwater and estuarine portions of the river for extended periods. Spring Chinook Salmon stocks with yearling life histories that migrate more rapidly through the estuary generally had low PCB concentrations, but high concentrations of DDTs. Lipid content was low (&lt;1%) in many of the fish examined, contributing to high lipid‐adjusted contaminants concentrations in some samples.

Congener specific distribution and health risk assessment of polychlorinated biphenyls in urban soils

Polychlorinated biphenyls (PCBs) were primarily used in transformers and capacitors, lubricants, flame retardants, plasticizers, paint, carbonless papers, etc. These are capable of long-range atmospheric transport and have been designated as persistent organic pollutants by the Stockholm Convention. Due to their characteristic properties, PCBs are found worldwide in all environmental matrices (including human) and biota. Soils are usually considered to be the source as well as sink for environmental pollutants, with cumulative effects of long-range atmospheric transport and local sources. Around the world, comparatively higher concentrations of PCBs have been reported in urban soils than suburban or rural soils. Higher amount of PCBs in urban soils may cause toxicological health risks to urban residents through ingestion, inhalation and skin contact. This paper presents the PCB distribution in soils from Delhi, India, and exposure risk estimates for human health through soil ingestion. The concentration of &amp;Sigma;PCBs ranged between 1.08-100.67 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; (mean 21.16 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;&amp;plusmn;5.24 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;), which was much lower than the Canadian soil quality guideline value of 1.3 mg/kg or 1300 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;. Human health risk estimates through the soil ingestion pathway were made in terms of lifetime average daily dose (LADD), incremental lifetime cancer risks and non-carcinogenic hazard quotient (HQ). The LADD for Delhi adults and children was 3.02x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; and 1.57x10&lt;sup&gt;&amp;ndash;7&lt;/sup&gt; mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;, respectively, which corresponds to toxic equivalent quotients (TEQ) intake of 0.105 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; (0.735 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; week&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;) and 0.543 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; (3.801 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; week&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;), respectively. The estimated LADD for Delhi residents was lower than the acceptable intake values recommended by the World Health Organization (1 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;), the European Commission (14 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;;1 week&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;) and by the Japanese government (4 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;). The probability of cancer risk ranges from 6.04x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; (&amp;Sigma;PCBs) to 1.57x10&lt;sup&gt;&amp;ndash;5&lt;/sup&gt; (&amp;Sigma;TEQ) and 3.13x10&amp;ndash;7 (&amp;Sigma;PCBs) to 8.15x10&amp;ndash;5 (&amp;Sigma;TEQ) for adults and children, respectively, and was within acceptable ranges of 10&lt;sup&gt;&amp;ndash;6&lt;/sup&gt; to 10&lt;sup&gt;&amp;ndash;4&lt;/sup&gt;. The non-carcinogenic risk in terms of health HQ was 0.105 and 0.330 for adults and children, respectively, which was lower than the acceptable limit of 1. The study found lower concentrations of PCBs than guideline values and low health risk estimates through the soil ingestion pathway within acceptable levels, indicating a minimum risk for Delhi residents.

Extraction of PCBs from Transformer Oil and Its Dechlorination Using Visible Light

AbstractAn investigation into an extraction of polychlorinated biphenyls (PCBs) from transformer oil (TO) using different solvents and its dechlorination with visible light was conducted. The extraction experiments showed that dimethyl sulfoxide (DMSO) was the preferable solvent for extraction of PCBs from TO, with an average of 88.79% recovery. Multicycle extractions using DMSO led to 87.93, 11.22, and 0.77% PCBs recovery during the first, second, and third cycles, respectively. Optimization studies indicated that for TO with low concentrations of PCBs, a 5-min shaking time, and a DMSO to TO ratio of 6∶1 is optimal. For higher concentrations of PCBs in TO, the optimum conditions were 30 min of shaking time with a DMSO to TO ratio of 6∶1. Furthermore, water aids in the extraction. PCBs were effectively dechlorinated using visible light in conjunction with sodium borohydride, NaBH4, as a reducing agent. The presence of DMSO did not seem to interfere with the dechlorination.

Interaction Between Persistent Organic Pollutants and C-reactive Protein in Estimating Insulin Resistance Among Non-diabetic Adults

ObjectivesChronic inflammation is now thought to play a key pathogenetic role in the associations of obesity with insulin resistance and diabetes. Based on our recent findings on persistent organic pollutants (POPs) including the lack of an association between obesity and either insulin resistance or diabetes prevalence among subjects with very low concentrations of POPs, we hypothesized that POP concentrations may be associated with inflammation and modify the associations between inflammation and insulin resistance in non-diabetic subjects.MethodsCross-sectional associations among serum POPs, C-reactive protein (CRP), and homeostasis model assessment of insulin resistance (HOMA-IR) were investigated in 748 non-diabetic participants aged ≥20 years. Nineteen types of POPs in 5 subclasses were selected because the POPs were detectable in ≥60% of the participants.ResultsAmong the five subclasses of POPs, only organochlorine (OC) pesticides showed positive associations with CRP concentrations, while polychlorinated biphenyls (PCBs) showed inverse associations with CRP concentrations. There were statistically significant interactions between CRP and OC pesticides and between CRP and PCBs, in estimating HOMA-IR (P for interaction <0.01 and <0.01, respectively). CRP was not associated with HOMA-IR among subjects with low concentrations of OC pesticides or PCBs, while CRP was strongly associated with HOMA-IR among subjects with high concentrations of these POPs.ConclusionsIn the current study, OC pesticides were associated with increased levels of CRP, a marker of inflammation, and both OC pesticides and PCBs may also modify the associations between CRP and insulin resistance.

Polychlorinated Biphenyl Congeners in River Sediments: Distribution and Source Identification Using Multivariate Factor Analysis

To assess the level of polychlorinated biphenyl (PCB) contamination and identify their sources, surface sediments were collected from selected locations along Nakdong River, Korea, and analyzed for 209 PCB congeners using high-resolution gas chromatography/high-resolution mass spectroscopy. PCB levels ranged from 0.124 to 79.2ng/g dry weight (coplanar PCBs 0.295 to 5720pg/g dry), which were similar to those of three other major rivers (Han, Geum, and Youngsan rivers) in Korea but slightly lower than those in neighboring countries. Regarding homologue composition, tetra-CBs were most abundant in most samples, but some samples with much higher PCBs concentrations had relatively lower proportions of tetra-CBs and higher proportions of penta- to hepta-CBs. To identify the sources of PCBs in sediment samples, principal component analysis/absolute principal component scores (PCA/APCS), positive matrix factorization (PMF), and multiple linear regression (MLR) were used with the congener composition of aroclors (1242, 1248, 1254, and 1260) and the flue gas of waste incinerators (data obtained from a previous article) as source profiles. Results showed that the three models showed similar source apportionments. Most sediment samples with lower PCB concentrations had higher proportions of incineration-derived materials, and some sediment samples with much higher PCB concentrations had higher proportions of aroclor 1260. This occurred because many industrial facilities, such as landfill leachate-treatment facilities, were gathered around sampling points with high PCB concentrations, and high-chlorinated PCBs are more stable in the elution process of landfill leachate than the incineration process. PCB concentrations estimated by APCS, PMF, and MLR were similar to the measured values with coefficients of determination ranging from 0.77 to 0.99.

Feasibility of two multidimensional techniques, heart‐cut MDGC and GC×GC, for the separation of PCBs and PBDEs

The feasibility of heart-cut MDGC-ECD and GCxGC-muECD for the separation of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) has been evaluated. Among the different column combinations tested, the best results were obtained when using either a DB-5 type or an HT-8 column as the first dimension combined with a mid-polar stationary phase (50% phenyl) as the second dimension. The co-elutions between the target PCBs and PBDEs in the first dimension were satisfactorily resolved once transferred to the second column. Repeatability and intermediate precision were satisfactory in both systems, considering retention times in both dimensions. Nevertheless, peak area/volume precision was better for heart-cut MDGC since software for the data analysis in the case of GCxGC was still under development. The need for multiple injections of the same extract on the heart-cut MDGC system was the main drawback since the analysis time it increased. GCxGC becomes then a valuable alternative able to achieve the same performance in one injection. However, the GCxGC data analysis is still very time-consuming and needs further development. The applicability of both separation techniques was shown using a human breast milk sample with low concentrations of PCBs (0.2-227 pg/g fresh weight) and PBDEs (1.2-41 pg/g fresh weight).