Environmental exposure to persistent organic pollutants measured in breast milk of lactating women from an urban area in central Poland

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe. The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum. Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 μg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population. This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Levels, patterns and risk assessment of PCDD/Fs and dl-PCBs through dietary exposure in the Valencian Region (Spain)

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCBs) levels were measured in representative vegetable oils and animal origin foodstuffs collected in a Total Diet Study carried out in the Valencian Region (Spain). A total amount of 3,300 food samples were collected and grouped into 5 main food groups: vegetable oils, meat and meat products, eggs, milk and dairy products and fish and sea products. The samples were analysed using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS). The food group which presented the highest concentration in wet weight (ww) for the sum of PCDD/Fs and dl-PCBs was fish and sea products (0.5 pg TEQ g-1 ww), whereas meat and meat products (0.6 pg TEQ g-1 lipid) showed the highest levels expressed in lipid terms. Occurrence data of PCDD/F and dl-PCBs were combined with consumption data to estimate the dietary exposure of adults (>15 years) and children (6-15 years). Finally, the estimated weekly intake (EWI) was calculated using a deterministic approach and considering the food consumption of the population, with fish and sea products being the main food group contributor. Likewise, considering the worst-case scenario (Upper Bound, UB), average EWI were 1.8 and 3.4 pg TEQ kg-1 body weight (bw) week-1 for adults and children, respectively. For children, the average EWI was almost twice above the tolerable weekly intake (TWI) of 2 pg TEQ kg-1 bw week-1 set by EFSA in 2018. In terms of risk characterisation, the overall obtained results showed that 19 % of adults and 43 % of children may exceed the TWI when using UB.

Polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in human milk from national human breast milk monitoring in 2016-2019 in China

Human breast milk monitoring programs were recommended to be carried out to assess human body burden to persistent organic pollutants and their temporal trends. Thus, we conducted a national survey during the period of 2016-2019 to determine PCDD/Fs and dl-PCBs in human breast milk from China. The total TEQ amounts in the upper bound (UB) was in the range of 1.97 to 15.1 pg TEQ g^-1 fat with a geometric mean (GM) of 4.50 pg TEQ g^-1 fat. 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD, and PCB-126 were more predominant contributors with the percentage contribution of 34.2 %, 17.9 %, and 17.4 %, respectively. By comparison with our previous monitoring results, the total TEQ in breast milk sample of the present study is statistically lower than that in 2011 with a reduction of 16.9 % in the average (p < 0.05), and comparable to that in 2007. The estimated GM of dietary intake of total TEQ for the breastfed was 25.4 pg TEQ kg^-1 body weight day^-1 that was higher than that of the adult. It is therefore worthy to make more efforts to reduce amounts of PCDD/Fs and dl-PCBs in breast milk and to continue monitoring to further observe if the amount of these chemicals continue to decrease.

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

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

Association of pre-pregnancy maternal overweight/obesity and dietary intake during pregnancy with the concentrations of persistent organic pollutants in the human milk of women from Rio de Janeiro, Brazil

Persistent organic pollutants (POPs) are toxic chemical compounds that can bioaccumulate, adhere to lipid matrices, and affect human health. This study aimed to investigate the association between maternal pre-pregnancy overweight/obesity and dietary intake during pregnancy and POP concentrations in the human milk of women from Rio de Janeiro, Brazil. One hundred and forty-seven women were followed from the third trimester of pregnancy until 119 days postpartum, and 77 human milk samples were analyzed between 2 and 119 days postpartum. POP concentrations were analyzed using gas chromatography-triple quadrupole mass spectrometry. Pregnancy dietary intake was estimated using a semi-quantitative food frequency questionnaire, and pre-pregnancy body mass index at baseline was classified as normal or overweight/obesity. Multiple logistic and linear regression models were performed to investigate the association between pre-pregnancy overweight/obesity, dietary intake during pregnancy, and POP concentrations in human milk. The models were adjusted for maternal age, maternal schooling, total cholesterol serum concentrations, and time postpartum. The analyses were corrected for multiple comparisons using the Benjamini-Hochberg test. Significant associations were observed between pre-pregnancy overweight/obesity and dichlorodiphenyldichloroethane (ppDDE), polychlorinated biphenyl (PCB)74, PCB138, PCB153, PCB170, PCB180, total PCBs, total 4PCBs, total 2 organochlorine pesticides (OCPs), and total POP concentrations. Higher daily lipid intake during pregnancy increased human milk hexachlorobenzene (HCB). This study showed that pre-pregnancy overweight/obesity and total lipid intake during pregnancy were associated with POP concentrations in the milk of women from Rio de Janeiro, Brazil. To promote adequate nutritional status since preconception and surveillance and control of POP in the environment could be essential to ensure binomial mother-infant health and biomonitoring studies and programs for these POPs should be stimulated.

Breastfed infants' exposure to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, and per- and polyfluoroalkyl substances: A cross-sectional study of a municipal waste incinerator in China

A municipal waste incinerator (MWI) in Zhejiang, China, operating since 2008 was completely reconstructed from 2016 to 2019. In 2013, we conducted a cross-sectional study of breastfeeding mothers living near the MWI. We evaluated the concentrations of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the mothers' breast milk and their infants' estimated daily intake (EDI). To investigate the temporal variations of these pollutants, we conducted a cross-sectional study of 29 mothers in 2019. We assessed the levels of 18 PCB congeners, 17 PCDD/F congeners, and 21 per- and polyfluoroalkyl substance (PFAS) congeners in breast milk and estimated the EDI. The mean total concentrations of PCDD/Fs (ΣPCDD/Fs) and PCBs (ΣPCBs) were 81.2 and 4.90 ng/g lipid, respectively, while the toxic equivalent quantity (TEQ) levels of ΣPCDD/Fs and dioxin-like PCBs (ΣDL-PCBs) were 2.7 and 1.4 pg WHO-TEQ/g lipid, respectively. Compared to our 2013 measurements, the mass concentrations of ΣPCDD/Fs and ΣPCBs decreased by 13% and 35%, respectively (3.361 vs. 2.915 pg/g wet weight [ww] and 269.1 vs. 175.0 pg/g ww, respectively). The TEQ-ΣPCDD/F levels decreased by 67% (0.241 vs. 0.080 pg/g ww), but the TEQ-ΣDL-PCB levels increased by 11% (0.046 vs. 0.051 pg WHO-TEQ/g ww). The median concentration of PFASs was 0.250 ng/mL, ranging from 0.151 to 0.833 ng/mL. The infants' mean EDI of total PCDD/Fs and DL-PCBs was 17.7 pg TEQ/kg body weight [bw], representing a 20% decline compared to 2013. The average EDI levels of PFOS, PFOA, and PFNA were 5.8, 17.9, and 1.7 ng/kg bw, respectively. A comprehensive comparison of the results with studies from around the world showed that the potential health risks posed by legacy PCDD/F and PCB pollutants were not as grave for mothers and infants living near this MWI, but the emerging PFAS pollutants represented a new cause for concern. MAIN FINDINGS: The potential health risks posed by legacy PCDD/F and PCB pollutants were not particularly serious for mothers and infants living near the MWI, but the emerging PFAS pollutants raised new concerns.

A retrospective study on dioxins and dioxin-like polychlorinated biphenyls in milk and dairy products from the Latium region (Italy) over a 7-year study period (2011-2017)

This study reports the data of polychlorinated dibenzo-p-dioxins (PCDDs), -furans (PCDFs), and polychlorinated biphenyls dioxin-like (dl PCBs) measured in a total of 260 samples of the dairy supply chain collected over a period of 7 years (2011-2017) in the Latium region (Italy). Levels and average profiles of congeners were reported for each group of the analyzed dairy matrices, and any differences between different sampling strategies were considered (around likely pollutant sources or casual sampling). Of the samples, 95.4% resulted compliant with the regulated levels; only samples belonging to the "sheep bulk milk" matrix were found to be above either the action levels or the maximum levels (tot. 12 samples). Raw milk of the sheep species showed the highest averages (PCDD/F 0.248 and dl PCB 0.966 WHO TEQ pg/g of fat) compared to the milk of other species. The buffalo milk showed a content of dl PCB significantly lower (dl PCB: 0.371 WHO TEQ pg/g of fat) than the sheep milk (p<0.05). Dioxins were found to be superior to furans in almost all dairy products, except in the noncompliant samples where furans were higher. The OCDD was found to be the most abundant congener in almost all dairy products. This study provides a first list of reference values for background contamination of the dairy supply chain in the Latium region. These pre-existing values will be useful in all cases of environmental pollution to identify critical situations.

PCDD/Fs and DL-PCBs in Chinese Mitten Crab (Eriocheir sinensis) and Its Farming Environment in Shanghai, China

Most polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in the human body are acquired from dietary intake. The chronic exposure of humans to PCDD/Fs and DL-PCBs is a major health concern, and these compounds are strictly controlled in many areas. This study measured the levels of PCDD/Fs and DL-PCBs in Chinese mitten crab (Eriocheir sinensis) farms in Shanghai and determined potential sources. The mean concentrations of PCDD/Fs and DL-PCBs in the studied crab samples were 264.20 ± 260.14 and 506.25 ± 226.80 pg/g ww (wet weight), respectively. The range of the toxic equivalent (TEQ) for the total PCDD/Fs and DL-PCBs in the crab samples was 1.20–29.04 pg TEQ/g ww. Further analysis revealed that the TEQ input to crabs in aquacultural water was 1.6 times higher than the TEQ in edible crab parts. Aquatic plants, shore plants, and feed contributed about 0.05% of the total TEQ input to crabs. The TEQ contribution from sediment was 317 times that found in edible crab parts, and sediment may be the most prevalent source of PCDD/Fs and DL-PCBs in farm crabs. The evaluation of the Shanghai market crab revealed different levels of PCDD/Fs and DL-PCBs. The TEQs for the mean PCDD/F and DL-PCB levels were 1.55 ± 1.96 and 1.05 ± 0.55 pg TEQ/g ww, respectively. The tolerable daily intake (TDI) levels of adults and children were lower than the prescribed range (1–4 pg TEQ/kg (weight)·d), indicating no significant chronic or acute ingestion risk for adults and children.

Mixture of environmental pollutants in breast milk from a Spanish cohort of nursing mothers

Breastfeeding is one of the most effective ways to ensure child health and survival, with several benefits for both the infants and their mothers. However, breast milk can contain environmental pollutants with endocrine disruption capacity, neurotoxicity and/or potential to alter microbiota. Monitoring breast milk provides information on the current chemical exposure of breastfed infants and, in addition, on the current and historical exposure of nursing mothers. In this study, the levels of a wide range of pollutants were measured in breast milk of Spanish nursing mothers. Target chemicals were dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), oxy-chlordane, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), per- and poly-fluoroalkyl substances (PFASs) (including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)), chlorpyrifos, bisphenol A (BPA), tetrabromobisphenol A (TBBPA), and a number of toxic and essential elements. Traces of most chemicals were found. A correlation between the levels of some persistent organic pollutants (POPs) and maternal characteristics (age and body mass index) was observed, while smoking was associated to higher concentrations of some toxic elements. Higher levels of PCBs were detected in samples from Spanish primiparous mothers compared to non-Spanish multiparous women. Breast milk from low-income mothers showed higher content of DDT and DDE than high-income mothers. Although breastfeeding is clearly beneficial for babies, the exposure to this mixture of hazardous substances, as well as their interaction and combined effects must not be disregarded.

Accumulation characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans and polychlorinated biphenyls in human breast milk from a seaside city of North China

Breast milk samples were collected from 51 mothers in a seaside city Dalian, where the residents usually have higher dietary exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) due to the larger consumption of seafood. The lipid-basis concentrations of ∑Cl_2-8DD/Fs, ∑Cl_2-10Bs, and total toxicity equivalent (WHO-TEQ) were measured to be in the ranges of 35.7-2727.8 pg/g, 4.91-52.64 ng/g, and 2.27-36.30 pg/g, respectively. The average proportion of ∑Cl_2-3DD/Fs was higher than that of ∑Cl_4-7DD/Fs in the collected human breast milk samples, suggesting that the health risk of Cl_2-3DD/Fs should be especially concerned. The concentration data of PCDD/Fs and PCBs in human breast milk essentially followed a positive skew probability distribution. Women in high-level exposure scenarios exhibited a higher potential to accumulate homologues Cl₄DFs, Cl₇DFs, Cl₈DF, and Cl₆Bs in breast milk. Three PCDD/F congeners (1,2,3,6,7,8-Cl₆DF, 1,2,3,4,7,8-Cl₆DF, and 1,2,3,4,6,7,8-Cl₇DD) and three PCB congeners (PCB 126, PCB 138, and PCB 169) were identified as good indicators for the accumulation of PCDD/Fs and PCBs in human breast milk, respectively. The food-to-milk accumulation factors (FMAF) were calculated to evaluate the accumulation potentials of different PCDD/F and PCB congeners in human breast milk via dietary exposure. The calculated FMAF value presented a non-monotonic variation with the logarithm of n-octanol-water partition coefficient (log K_OW) with a peak at a log K_OW value of about 7.3 and a valley at a log K_OW value of about 8. The mean value of the estimated daily intake (EDI) of total WHO-TEQ for breast-fed infants in Dalian, predicted by Monte Carlo simulation, was 10 folds higher than the upper range of the tolerable daily intake (TDI) value (4 pg WHO-TEQ/kg bw/d), suggesting continued and enhanced efforts should be made to reduce the exposure risk of infants to PCDD/Fs and PCBs.

Exposure and risk assessment of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) for primiparous mothers and breastfed infants in Penang, Malaysia

An average 50 ml breast milk samples were collected from 21 lactating primiparous mothers (range 25 to 45 years, mean 33 years), 4-8 weeks after delivery in Penang Island, Malaysia. The geometric mean concentration of the most toxic congeners, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) was 0.14 pg WHO₂₀₀₅-TEQ g^-1 zlipid. The most abundant congeners of PCDD/Fs were octachlorodibenzo-p-dioxin (OCDD) (5.9-75.4%), followed by 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (1,2,3,4,6,7,8-HpCDD) (1.1-30.7%). The geometric mean level of total dioxins and dl-PCBs was 2.2 pg WHO₂₀₀₅-TEQ g^-1 lipid, significantly lower than those in developed countries or highly contaminated areas. The total dioxins and dl-PCBs in pg WHO₂₀₀₅-TEQ levels in breast milk were significantly correlated with years of residence at potential contaminated site. The average daily intake of 11.8 pg WHO₂₀₀₅-TEQ kg^-1 body weight was estimated for a breastfed infant at 6 months of age. This demonstrates the exposure risk to infants, especially from Penang region, to these pollutants from human milk intake are potentially high during the lactation period.