Indicator Polychlorinated Biphenyls Research Articles

Systematic investigation of organochlorine pesticides and polychlorinated biphenyls blood levels in Greek children from the Rhea birth cohort suggests historical exposure to DDT and through diet to DDE

The blood levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been thoroughly investigated in Greek children from the Rhea birth cohort study. This investigation aimed to assess exposure levels, explore their possible relationship with children's age and sex, and indicate potential sources of exposure. Exposure patterns and common sources of PCBs and OCPs were analyzed using bivariate and multivariate statistics.A total of 947 blood samples from study participants were analyzed for OCP and PCB exposure, with 375 samples collected at 4 years old, 239 at 6.5 years old, and 333 at 11 years old. Elevated levels of DDE were observed in 6.5-year-old children compared to corresponding levels in other European countries. Higher levels of DDE were found in 4-year-old children, with the lowest concentrations in the 11-year-old group. The DDT/DDE ratio was consistently less than 1 among all the examined subjects. These results indicate exposure to DDT and DDE both in utero and through breastfeeding and dietary intake. For the entire cohort population, the highest concentration was determined for PCB 28, followed by PCBs 138, 153, and 180. The sum of the six indicator PCBs implied low exposure levels for the majority of the cohort population. Spearman correlations revealed strong associations between PCBs and OCPs, while principal component analysis identified two different groupings of exposure. DDE exhibited a correlation with a series of PCBs (153, 156, 163, 180), indicating a combined OCP-PCB source, and an anticorrelation with others (52, 28, 101), implying a separate and competing source.

Serum polychlorinated biphenyl levels and circulating miRNAs in non-obese women with and without polycystic ovary syndrome.

Polychlorinated biphenyls (PCBs), organic lipophilic pollutants that accumulate through diet and increase with age, have been associated with polycystic ovary syndrome (PCOS) and shown to affect microRNA (miRNA) expression. This work aimed to determine if PCBs were associated with circulating miRNAs and whether there were any correlations with serum PCB/miRNA levels and hormonal changes. 29 non-obese PCOS and 29 healthy control women, with similar age and body mass index (BMI), had their serum miRNAs measured together with 7 indicator PCBs (PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, PCB180) using high resolution gas chromatography coupled with high resolution mass spectrometry. In the combined study cohort, four miRNAs (hsa-miR-139-5p, hsa-miR-424-5p, hsa-miR-195-5p, hsa-miR-335-5p) correlated with PCBs, but none correlated with metabolic parameters. hsa-miR-335-5p correlated with FSH. When stratified, 25 miRNAs correlated with PCBs in controls compared to only one (hsa-miR-193a-5p) in PCOS; none of these miRNAs correlated with the metabolic parameters of BMI, insulin resistance, or inflammation (C-reactive protein, CRP). However, of these 25 miRNAs in controls, hsa-miR-26a-5p, hsa-miR-193a-5p, hsa-miR-2110 and hsa-miR-195-5p positively correlated with luteinizing hormone (LH), hsa-miR-99b-5p and hsa-miR-146b-5p correlated with estradiol, hsa-miR-193a-5p correlated with progesterone, hsa-miR-195-5p correlated with follicle stimulating hormone (FSH), and hsa-miR-139-5p and hsa-miR-146b-5p negatively correlated with anti-müllerian hormone (AMH) (all p<0.05). hsa-miR-193a-5p in PCOS cases correlated with estradiol. In this cohort of women, with no difference in age and BMI, and with similar PCB levels, the miRNAs correlating to PCBs associated with menstrual cycle factors in healthy menstruating controls versus the anovulatory PCOS subjects. The PCB-associated miRNAs did not correlate with non-reproductive hormonal and metabolic parameters. This suggests that PCB effects on miRNAs may result in changes to the hypothalamo-ovarian axis that may thus affect fertility.

POPs in the Mongolian environment

An environmental and human monitoring project analyzing the persistent organic pollutants (POPs) listed in the Annexes of the Stockholm Convention on POPs was implemented in Mongolia with sampling activities from 2017 until 2019. In support of the global monitoring plan implementation, a total of 51 samples were analyzed for POPs whereby 23 POPs were detected frequently. Two POPs, endrin and hexabromobiphenyl (PBB 153), were not quantified in any of the samples; toxaphene was found only twice in air samples; and dicofol, pentachlorophenol, and short-chain chlorinated paraffins were analyzed only in one human milk sample. Most results were for perfluorooctanoic acid (PFOA, 32 of 43 samples) and perfluorooctanesulfonic acid (PFOS, 31 of 43 samples). With respect to detection frequency, dioxin-like polychlorinated biphenyls (dl-PCB) were detected in 100% of the samples analyzed (N = 28). On scale, highest amounts were found in soil samples, almost 30 000 ng/g for lindane, more than 13 000 ng/g for α-hexachlorocyclohexane (α-HCH), and almost 10 000 ng/g for dichlorochlorodiphenyltrichloroethane (DDT) and its transformation products. The soil and ambient air samples were the drivers towards highest values in the abiotic samples, due to the presence of legacy POPs such as DDT, indicator PCB, HCHs but also hexachlorobenzene (HCB), and pentachlorobenzene (PeCBz). Concentrations of dioxin-like POPs were low in general as were the perfluorinated substances (PFAS). With respect to brominated flame retardants, the presence of hexabromocyclododecane in air samples was surprising. At present, the analytical capacity to analyze POPs in various matrices under the global monitoring plan for POPs is being set-up to strengthen future environmental monitoring activities in Mongolia.

Metadata Analysis of Persistent Organic Pollutants in National Pools of Human Milk in Support of the Stockholm Convention Implementation

A set of human milk samples, consisting of pools from up to 50 mothers that delivered their first baby was assessed for the persistent organic pollutants (POPs) listed in the Stockholm Convention. It must be noted that only samples that qualified for the criteria, as established in the global monitoring plan of the Stockholm Convention, following an initial protocol from the World Health Organization, were included. The data do not allow for an assessment of POP concentrations in breast milk with lactation period nor, in most cases and when not indicated otherwise, a comparison within the same country. The assessment does not rank the POPs as to the risk for breastfeeding. Rather the measurements provide a basis for countries to compare among POPs or with other countries. A regional preference for certain POPs could not be identified; thus, taking into account global food supply chains and local production elsewhere does not allow us to prioritize a country for a certain POP. Although the highest concentrations were always found for the sum of DDT, these samples were not prominent in multivariate statistical analyses. The best indicator for the scale of POPs in breast milk was the sampling year: the earlier a national pool was created, the higher and the wider spread were the concentrations: see the example of dioxin-like POPs and indicator PCB. For some POPs, the income of a country seems to indicate scale and POP compounds. The population density was not found to be a suitable predictor or discriminator. Since all POPs seemed to level off and some POPs were only measured after the entry-into-force of the Stockholm Convention in 2004, we do not have a strong indicator to determine POP concentrations in the 1980s or before.

Spatial characteristics, sources and exposure risk of polychlorinated biphenyls in dusts and soils from an urban environment in the Niger Delta of Nigeria

Chlorinated organic compounds, such as polychlorinated biphenyls (PCBs), are a threat to both humans and the environment because of their toxicity, persistence, and capacity for long-range atmospheric transport. The concentrations of 28 PCB congeners, including 12 dioxin-like and seven indicator PCBs, were investigated in soils, and indoor and outdoor dusts from Port Harcourt city, Nigeria, in order to evaluate the characteristic distribution patterns in these media, their sources, and possible risk. The PCB concentrations varied from 4.59 to 116 ng g−1 for soils, and from 1.80 to 23.0 ng g−1 and 2.73 to 57.4 ng g−1 for indoor and outdoor dusts respectively. The sequence of PCB concentrations in these matrices was soil > outdoor dust > indoor dust. The composition of PCBs in these matrices indicated the prevalence of lower chlorinated PCBs in indoor and outdoor dusts, while the higher chlorinated congeners were dominant in soils. Di-PCBs were the predominant homologues in indoor dusts, while deca-PCBs were the most prevalent homologues in outdoor dusts and soils. The TEQ values of dioxin-like PCBs in 60 % of the soils, 100 % of the indoor dust, and 30 % of the outdoor dust were above the indicative value of 4 pg TEQ g−1 established by the Canadian authority. The hazard index (HI) values for exposure of adults and children to PCBs in these media were mostly greater than one, while the total cancer risk (TCR) values exceeded the acceptable risk value of 10−6, which indicate probable non-carcinogenic and carcinogenic risks resulting from exposure to PCBs in these media. Source analysis for PCBs in these matrices shows that they originated from diverse sources.

Preliminary trends over ten years of persistent organic pollutants in air - Comparison of two sets of data in the same countries

In two series of ambient air measurement campaigns to support the implementation of the global monitoring plan (GMP) component of the Stockholm Convention on Persistent Organic Pollutants (POPs), passive air samplers (PAS) using polyurethane foams were implemented by the United Nations Environment Programme (UNEP). With the same laboratories responsible for the chemical analyses of the different groups of POPs, a total of 423 PUFs were analyzed for organochlorine pesticides (OCPs) including hexachlorobenzene (HCB) and polychlorinated biphenyls (PCB); 242 for dioxin-like POPs. For trend analysis, to compare amounts of POPs in the PUFs during the first phase in 2010/2011 and the second phase from 2017 to 2019, only results were assessed that were generated in the same country and for the same POP in both campaigns. Finally, there were 194 PUFs available for OCPs (GMP1 = 67 and GMP2 = 127), 297 for PCB (GMP1 = 103, GMP2 = 194), 158 for polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD, PCDF) (GMP1 = 39, GMP2 = 119), and 153 for dl-PCB (GMP1 = 34, GMP2 = 119). Indicator PCB and dioxin-like POPs were quantified in all countries at all times; decreases of about 30% based on median values were determined. A 50% increase was found for HCB. By scale, DDT remained with the highest values, although more than 60% decrease was found; mainly due to smaller values in the Pacific Islands region. Our assessment showed that on relative scale – per PUF – trend analysis was achieved and that such approach should be undertaken at regular intervals, not necessarily on an annual basis.

Assessment of organohalogenated pollutants in breast milk from the Czech Republic

This biomonitoring survey brings new information on the occurrence of a total of 94 organohalogenated pollutants in 231 human breast milk samples collected in 2019 and 2021 from women living in two regions of the Czech Republic (Karvina and Ceske Budejovice). This study aimed to evaluate the concentrations of 6 indicator polychlorinated biphenyls (PCBs), 10 organochlorine pesticides (OCPs), 34 halogenated flame retardants (HFRs), 29 perfluoroalkyl and polyfluoroalkyl substances (PFAS) and 15 polychlorinated naphthalenes (PCNs). PCBs, OCPs, most of HFRs and PCNs were identified/quantified by gas chromatography coupled to (tandem) mass spectrometry (GC–MS(/MS)), while PFAS, hexabromocyclododecane isomers (HBCD), brominated phenols, and tetrabromobisphenol A (TBBPA) by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS). The mean value of the sum of the 6 indicator PCBs was 123.12 nanogram per gram of lipid weight (ng g−1 lw). Hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH) and p,p’-dichlorodiphenyl-dichloroethylene (p,p’-DDE) were the most abundant OCPs, detected in 100 % (mean 11.8 ng g−1 lw), 94.8 % (mean 6.1 ng g−1 lw) and 100 % (mean 101.5 ng g−1 lw) of samples, respectively. PCN congeners 20, 52 and 66 were detected in <1 % of the samples. The HFRs concentrations were relatively low compared to the levels of OCP; The detection rate of polybrominated diphenyl ethers (PBDEs, # 47, 99 and 153) ranged 21–68 % with a mean concentrations of 0.34 ng g−1 lw - 0.42 ng g−1 lw. PFAS concentrations were also low, with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) dominant in this group (means of 22 pg ml−1 and 21 pg ml−1, respectively). Our results confirmed the long-term trend of declining levels of banned POPs in Czech mothers. The amounts of PCBs and OCPs were higher in older breastfeeding primiparous women.

Inhalation and dermal absorption as dominant pathways of PCB exposure for residents of contaminated apartment buildings.

Applications of polychlorinated biphenyls (PCBs) in buildings and their persistence in indoor environments have led to cases of current and highly elevated exposure in humans, despite the global cease of production decades ago. Personal exposure to PCBs was assessed among residents in a social housing estate in Denmark containing both contaminated (n = 67) and non-contaminated (n = 23) apartments. Samples and estimated daily intakes (EDIs) were assessed for 15 PCB congeners, and body burden, which was limited by the dietary data availability, was compared across 7 indicator PCBs, with its sum (PCBsum7) often applied in European regulation of PCBs. Median PCBsum7 EDI across measured pathways for exposed residents was 101 ng· (kg bodyweight)-1· day-1, with the majority of exposure (60%) coming from inhalation of contaminated indoor air. Calculated from both PCBs measured in indoor air and on hand wipes, dermal absorption estimates showed comparable results and served as a secondary exposure pathway, accounting for 35% of personal exposure and considering selected assumptions and sources of physical-chemical parameters. Estimates revealed that diet was the primary PCB source among the reference group, accounting for over 75% of the PCBsum7 EDI across exposure routes. When evaluating overall EDIs across the two study groups and including dietary estimates, PCB exposure among exposed residents was around 10 times higher than the reference group. Solely within the exposed population, pathway-specific body burdens were calculated to account for exposure across years of residence in contaminated apartments, where lower chlorinated PCBs were dominant in indoor air. Among these dominant congeners, estimated body burdens of PCB-28 and -52 were significantly correlated with measured serum (rs = 0.49, 0.45; p < 0.001). This study demonstrates that inhalation and dermal absorption serve as dominant exposure pathways for residents of apartments contaminated with predominantly lower chlorinated PCBs and suggest that predictions of body burden from indoor environment measurements may be comparable to measured serum PCBs.

Polychlorinated biphenyls (PCB) and polychlorinated dibenzo-para-dioxins and dibenzofurans (PCDD/F) in ambient air and deposition in the German background

PCDD/Fs (17 congeners and Σ tetra -to octachloro homologues) and 209 PCBs were investigated in monthly samples of ambient air (gas + particle phase) and atmospheric deposition at two background monitoring sites in Germany in 2018/19. In atmospheric deposition samples, PCDD/F congeners as well as certain PCBs were frequently below the method quantification limits whereas values for PCDD/F homologue groups could be quantified more often. Annual deposition averages for individual PCDD/Fs were between <0.1 μg/m2d and 6.7 μg/m2d. Averages for Σ TeCDD/F to OCDD/F homologue totals in deposition were about 11 pg/m2d and 19 pg/m2d. Total PCB deposition rates were about 1900 pg/m2d and 1550 pg/m2d. PCDD/F + PCB-deposition rates were below 1 pg WHO2005-TEQ/m2d on average. In ambient air, both substance groups were frequently observed. Annual concentration averages for individual PCDD/F were between 0.1 fg/m³ and 50 fg/m³. Average values for Σ TeCDD/F to OCDD/F homologue totals in ambient air were 283 fg/m³ and 162 fg/m³. Total PCB concentrations were about 50 pg/m³ at both sites. PCDD/F + PCB-TEQ values were lower than 5 fg WHO2005-TEQ/m³ on average. Besides the frequently studied dioxin-like PCBs and six indicator PCBs, the analysis of the 209 PCBs (166 separated PCB-peaks) enabled the identification and evaluation of additional PCBs that might be of environmental concern. Of 166 PCBs or PCB-coelutions, up to 144 were quantified in air samples and up to 94 in atmospheric deposition samples. In ambient air, some of these PCBs were observed at levels similar to or exceeding those of the six indicator PCBs. Important additional PCBs in ambient air were PCB 5 + 8, PCB 11, PCB 17, PCB 18, PCB 20 + 33, PCB 31, PCB 43 + 49, PCB 44, PCB 47 + 48 + 65 + 75, PCB 93 + 95 + 98 + 102, PCB 139 + 149, and PCB 151. The presence of these PCBs in atmospheric samples implies that by analysing only selected PCBs potentially important contaminants are overlooked.

LEVELS OF INDICATOR POLYCHLORINATED BIPHENYLS IN HUMAN MILK FROM VARNA REGION, BULGARIA

Human milk is an appropriate tool for the assessment of the body burden of humans with lipophilic persistent organic pollutants such as polychlorinated biphenyls (PCBs). Purpose: The aims of the study were to determine the levels of polychlorinated biphenyls in the breast milk of women living in Varna, Bulgaria and to evaluate the association with demographic characteristics. Material and methods: Breast milk samples were collected in 2019 - 2020 from 28 healthy primiparae mothers. The six indicator PCB congeners were determined in individual mother's milk samples by capillary gas chromatography system with mass spectrometry detection (GC-MS). Results: The predominant PCB congener measured in human milk was PCB 153, followed by PCB 138 and PCB 180. The lower chlorinated congeners PCBs (28, 52 and 101) were found below the limit of detection in most individual samples. The median level of the Indicator PCBs in milk samples was 29.1 ng/g lipid weight. The highest PCBs levels were found in breast milk from primiparae mothers 36 – 40 age (36.8 ng/g lipid as a sum of six Indicator PCBs), suggesting bioaccumulation of these pollutants. Conclusions: Positive association was found between the Indicator PCBs levels and the age of mothers. The levels of the Indicator PCBs in breast milk were found to be lower than levels reported in other studies in the European countries.

Update of Indicator PCB Levels in Food in Southern Italy: Assessment of the Dietary Exposure for Adult and Elderly Population

The levels of non-dioxin-like PCB indicators (iPCBs 28, 52, 101, 138, 153, and 180) were determined in food samples (seafood, meat and processed meat, milk and dairy products, hen eggs, olive oil, and other fats) to evaluate the exposure of adult and elderly population. iPCB levels in samples were in the following order: fishery products &gt; meat and processed meat &gt; milk and dairy products &gt; olive oil and other fats. None of the samples had concentrations above the maximum permissible limits for human consumption established by the European Union legislation, except for salami samples. The dietary intake for the total population was 12.33 ng·kg−1 bw·d−1, while depending on the sex/age groups, exposure was estimated between 9.60 and 12.11 ng·kg−1 bw·d−1, with seafood being the major contributor. The exposure scenario indicates that further efforts must still be carried out to protect the consumer from these harmful chemicals.

Occurrence and distribution of persistent organic pollutants (POPs) in the atmosphere of the Andean city of Medellin, Colombia

Passive air sampling (PAS) was used to evaluate organochlorine pesticides, polychlorinated biphenyls, polybrominated diphenyl ethers, polybrominated biphenyl, hexabromocyclododecane, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and perfluoroalkane substances in the atmosphere of Medellin, Colombia.PAS was carried out for three months (four quarters per year) over two consecutive years (2017 and 2018). This study allowed establishing the baseline of some pollutants in the city against which future temporal trends can be assessed. Furthermore, monitoring results suggested releases of DDT in the city or surrounding areas despite this pollutant was banned many years ago in the country. Moreover, this study evidenced the limited scope of the national laboratories to analyze persistent organic pollutants, specially brominated and fluorinated contaminants. However, there is an installed capacity to analyze organochlorine pesticide and indicator PCB in future national monitoring plans. Therefore, it is essential to realize efforts to improve the analytical capacity and increase the scope of the national laboratories. Furthermore, the PAS strategy was valuable for monitoring these pollutants in air. Finally, the results provide an overall view of persistent organic pollutants levels and represent an initial attempt to monitor and surveillance the releases of these pollutants in the city.

An environmental friendly and stable analytical method for the determination of indicator polychlorinated biphenyls (PCBs) in solid and waste oil samples by gas chromatography-electron capture detector (GC-ECD)

This study presents the optimization and comprehensive verification studies of a stable analytical method for the determination of seven indicator polychlorinated biphenyls (PCBs) in solid and waste oil samples by using gas chromatography-electron capture detector (GC-ECD). In extraction method optimization, the maximum efficient and environmentally compatible extraction conditions were obtained at 30 mL hexane:acetone (3:1) use and 1.25 min solvent hold time. In validation studies, this method indicated an excellent linearity from 50 μg/L to 500 μg/L since the correlation coefficients higher than 0.9975 for all PCBs. The LOD values varied from 10.1 μg/L to 10.3 μg/L and the LOQ values ranged from 33.7 μg/L to 45.5 μg/L. The mean recoveries in soil, sewage sludge and waste oil varied as 85.6–97.7 %, 82.8–91.2 %, and 96.2–108.8 %, respectively. The intra-day precision (RSD, (%) in soil, sewage sludge and waste oil varied as 3.73–6.33 %, 3.72–8.91 %, and 1.37–5.44 %, respectively, whereas the inter-day precision (RSD, (%)) in sewage sludge changed from 2.35 to 9.74 %. In trueness, both results from CRMs (the recovery of PCBs varied 84.3 % to 114.4 %) and PTs (z-scores for indicator PCBs varied from (−0.5 to 1.65) demonstrate that this method possesses well enough and sufficient capability for the rapid, selective, and correct determination of indicator PCBs in soil and waste oil samples. There was no critical ME (recovery varied from 82.6 to 99.5 % in all matrices) and the RSD (%) values for each matrices was below 6 %. In the measurement uncertainty, the expanded uncertainties (µg/kg) of seven indicator PCBs changed from 3.50 to 4.38. The contributions from the sample preparation (45.19–53.83 %), the calibration curve (20.34–27.04 %) and the repeatability (11.80–18.02 %) were the major sources to the expanded uncertainty. In real samples, eleven sewage sludge, two soil, and twenty-seven waste oil samples had results above the LOQ for at least one indicator PCB.

Association between dietary quality indices and serum polychlorinated biphenyls and organochlorine pesticides levels among Lebanese adults.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) remain a global concern in both developed and developing countries. Given that diet constitutes the major route of exposure to these pollutants, the objective of the current study is to investigate PCBs and OCPs serum levels in relation to dietary quality indices in a sample of Lebanese adults. Sociodemographic, nutritional, and anthropometric data were obtained from 302 participants in face-to-face interviews. Nutritional intakes from a previously validated quantitative 164-item food frequency questionnaire were used to calculate six a priori dietary indices: Healthy Eating Index (HEI-2015), alternate Healthy Eating Index (aHEI), Diet Quality Index-International (DQI-I), Mediterranean Diet Quality Index (Med-DQI), Med-DQIf, Mediterranean Diet Scale (MDS), and Mediterranean Diet Score (MedDietScore). Serum levels of six indicator PCBs (PCBs 28, 52, 101, 138, 153, 180) and four OCPs (HCB, β-HCH, DDT, and DDE) were investigated in relation to diet quality indices. Individuals with a higher adherence to the HEI-2015 and to the Mediterranean diet assessed by the Med-DQI/Med-DQIf displayed increased levels of OCPs (HCB, βHCH, DDT, and DDE). An inverted U-shaped association was observed between DQI-I and PCBs serum levels (PCBs 138, 153, 180, and ƩPCBs). This is the first study in the Middle East and North Africa region to investigate the association between POPs serum levels and a substantial number of a priori dietary indices. The impact of different food combinations and nutrient interactions on pollutants body burden and toxicity remains to be established in future studies.

OCCURRENCE AND POTENTIAL HEALTH RISKS OF INDICATOR POLYCHLORINATED BIPHENYLS (PCBs) IN SELECTED MARINE FISH SPECIES, RASTRELLIGER KANAGUTRA AND SIGANUS SUTOR. A CASE OF DAR ES SALAAM

The occurrence of polychlorinated biphenyls (PCBs) in marine fish and their potential health risks was assessed in Dar es Salaam region. Six indicator PCBs were assessed in selected marine fish species, Rastrelliger kanagutra and Siganus sutor collected from the Kivukoni-Feri, the major fish market and fishermen landing site in Dar es Salaam. Fish samples were extracted using the QuEChERS method and quantified by GC-MS/MS. The concentration of detected PCBs congeners in the analysed fish species was relatively low, ranging from &lt;LOD to 3.71 ng/gw/w in R. kanagutra and from &lt;LOD to 0.58 ng/g w/w in S. sutor species. However, the sum of mean PCBs concentration levels was below the maximum residue limit (MRL) of 75 ngg-1w/w set by the European Commission (EC) in the muscle of fish and fishery products. Estimated lifetime cancer risks were categorised as very low in both children and adults, with indices values ranging from 1.24E-08 to 6.14E-07 for children and 5.14E-09 to 2.55E-07 for adults, while non-carcinogenic risks were insignificant as the estimated hazard indices were less than 0.1 for both children and adults.

Detection of indicator polychlorinated biphenyls (I-PCBs) and polycyclic aromatic hydrocarbons (PAHs) in cow milk from selected areas of Dhaka, Bangladesh and potential human health risks assessment

In this study, the levels of indicator PCBs congeners and PAHs compounds were reported in cow milk from selected areas in Dhaka, Bangladesh, and the potential human health risks were assessed. A total of 100 milk samples were collected and analyzed using gas chromatography-tandem mass spectrometry (GC-MS/MS). Method validation was performed using recovery performance, linearity, limit of detection (LOD), and limit of quantification (LOQ) assays. PCBs congeners, including PCB No. 52 (2,2´,5,5´-tetrachlorobiphenyl), PCB No. 101 (2,2´,4,5,5´-pentachlorobiphenyl), PCB No. 153 (2,2,4,4,5,5–hexachlorobiphenyl), and PCB No 209 (Decachloro-1,1′-biphenyl perchlorobiphenyl) were detected, whereas PCB No 28 (2,2 ´,4–trichlorobiphenyl), PCB No. 138 (2,2´,3,4,4´,5´–hexachlorobiphenyl), and PCB No 180 (2,2´,3,4,4´,5,5´–heptachlorobiphenyl) were not detected in the analyzed milk samples. Among the 16 PAHs compounds, benzo (a) anthracene and chrysene were detected in milk samples. The Σ hazard risk index (HI) of all detected PCBs congeners was below the limit set by the European Food Safety Authority, which indicates limited health risks to animals and humans in the study area. However, the presence of PCBs and PAHs in milk samples from industrial areas may negatively affect human health, and further detailed studies are required to ensure public health safety.

Occurrence and risks of PCDD/Fs and PCBs in three raptors from North China

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were investigated in muscle samples from common kestrels (Falco tinnunculus), eagle owls (Bubo bubo), and little owls (Athene noctua) collected in Beijing, China. The concentrations of PCDD/Fs were in the ranges of 22.7–5280, 67.5–1610, and 68.4–3180 pg/g lipid weight (lw), while levels of dioxin-like PCBs ranged from 4.91 to 1560, 8.08–294, and 28.2–3540 ng/g lw, in common kestrel, eagle owl, and little owl, respectively. The main PCDD/Fs congener was 2,3,4,7,8-PeCDF, and CB-153 dominated the seven indicator PCBs. PCB levels have shown a decreasing trend in the last decade for the common kestrel, but not for little owl in Beijing, which exhibited higher levels of pollutants and toxic equivalency (TEQ) values than the other two species. Concentrations of PCDD/Fs, dioxin-like PCBs, and indicator PCBs differed between fledgling and adult raptors for certain species. Raptors in this study generally had a higher TEQ than the no-observed-effect level in the literature, indicating significant exposure risks to PCDD/Fs and dioxin-like PCBs in raptors, especially in adult little owls.

Modelling past human internal exposure to lower chlorinated indicator PCBs using proxies – A calculation based on multiple longitudinal PCB analyses

Polychlorinated biphenyls (PCBs) are persistent organic pollutants with former applications in electric transformers, capacitors, hydraulic fluids or joint sealants. While current internal exposure to PCBs can be readily assessed by human biomonitoring, the evaluation of longgone past exposures, in particular the estimation of past exposure to lower chlorinated non-dioxin-like PCB 28, 52 or 101 is limited due to the relatively short biological half-life of these PCB-congeners. This study was aimed to find a proxy that would allow an estimation of the former plasma level for these congeners even several years after exposure cessation. We used biomonitoring data of the German HELPcB cohort with six consecutive follow-up investigations and identified the congeners PCB 66, 74 and 99 as suitable proxies for the congeners of interest. The biological half-lives of the proxies as well as their individual correlation with the plasma levels of PCB 28, 52 and 101 was considered in the calculation models. The correlation coefficients and the inter correlation coefficient 3 (ICC3) between measured and calculated initial values were applied for validation. For external validation purposes we used longitudinal biomonitoring data from two different cohorts with indoor exposure to lower chlorinated PCBs.The backward estimation from current PCB 74 levels to former PCB 28 levels led to an ICC3 of 0.682 and a correlation of rho = 0.724 within the HELPcB cohort. The external validation revealed an ICC3 of 0.723 and a correlation of rho = 0.654. The external validation for PCB 101 was feasible, but measures were not comparably good (ICC3 = 0.460; Rho = 0.516). External validation for PCB 52 was not successful, maybe due to the lower level of burden. Our model shows that a rough estimation of former plasma levels of lower chlorinated PCBs is possible even years after exposure cessation using current measurements of PCB74.

Multiple persistent organic pollutants in mothers' breastmilk: Implications for infant dietary exposure and maternal thyroid hormone homeostasis in Uganda, East Africa

Persistent organic pollutants (POPs) are ubiquitous contaminants with adverse health effects in the ecosystem. One of such effects is endocrine disruption in humans and wildlife even at background exposure concentrations. This study assessed maternal breastmilk concentrations of POPs; brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), and the potential health risks posed to the nursing infants. We also evaluated the association of these POPs with total 3,3′,5-triiodo-L-thyronine (T3), L-thyroxine (T4), and 3,3′,5′-triiodo-L-thyronine (rT3) levels measured in human breast milk. Thirty breastmilk samples were collected from Kampala, Uganda between August and December 2018. Hexabromobenzene was not detected while the maximum level of 2,2′,4,4′,5,5′-hexabrombiphenyl was 64.7 pg/g lw. The median levels of total indicator PCBs, PBDEs, dioxin-like PCBs, and PCDD/Fs in the samples were 159 pg/g lw, 511 pg/g lw, 1.16 pg TEQ/g lw, and 0.4 pg TEQ/g lw, respectively. These levels were lower than those reported in other countries. Owing to their bio accumulative nature, PCBs −81, −169, and ∑PCDD/Fs increased with increase in maternal age. Estimated dietary intakes for dioxin-like PCBs and PCDD/Fs were lower than those reported elsewhere but were higher than the WHO tolerable daily intakes suggesting potential health risks to nursing infants. In adjusted single pollutant models, PCB-126, PCB-169, and ∑PCBTEQ were negatively associated with T3, while 1,2,3,4,5,7,8-HpCDF was positively associated with rT3. Although these associations did not persist in multipollutant models, our findings suggest potential thyroid hormone disruption by POPs in mothers. This may reduce the levels of thyroid hormones transferred from the mother to the neonates and, hence, adversely influence infant growth. A temporal study with a bigger sample size is required to corroborate these findings.

Atmospheric Concentrations and Health Implications of PAHs, PCBs and PCDD/Fs in the Vicinity of a Heavily Industrialized Site in Greece

Background: Thriassion Plain is considered the most industrialized area in Greece and thus a place where emissions of pollutants are expected to be elevated, leading to the degradation of air quality. Methods: Simultaneous determination of polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) was performed in PM10 samples. SPSS statistical package was employed for statistical analysis and source apportionment purposes. Cancer risk was estimated from total persistent organic pollutants’ (POPs) dataset according to the available literature. Results: POPs concentrations in particulate matter were measured in similar levels compared to other studies in Greece and worldwide, with mean concentrations of ΣPAHs, ΣPCDD/Fs, dioxin like PCBs, and indicator PCBs being 7.07 ng m−3, 479 fg m−3, 1634 fg m−3, and 18.1 pg m−3, respectively. Seasonal variations were observed only for PAHS with higher concentrations during cold period. MDRs, D/F ratios, and principal component analysis (PCA) highlighted combustions as the main source of POPs’ emissions. Estimation of particles’ carcinogenic and mutagenic potential indicates the increased toxicity of PM10 during cold periods, and cancer risk assessment concludes that 3 to 4 people out of 100,000 may suffer from cancer due to POPs’ inhalation. Conclusions: Increased cancer risk for citizens leads to the necessity of chronic POPs’ monitoring in Thriassion Plain, and such strategies have to be a priority for Greek environmental authorities.