Contamination pathways of polychlorinated biphenyls (PCBs) – From the worker to the family

Occupational exposure to polychlorinated biphenyls: Development of neuropsychological functions over time

Occupational exposure to polychlorinated biphenyls (PCBs) continues to affect the health of exposed individuals until today. This study aims to expand previous findings by examining the development of neuropsychological functions of occupationally exposed participants over time. Especially verbal fluency and sensorimotor processing, found to be impaired in a previous study, were thus of particular interest. A total of 116 participants, who were part of the HELPcB cohort, underwent a neuropsychological test battery covering a multitude of cognitive functions. Plasma PCB levels were determined for each participant and classified as elevated or normal based on comparative values drawn from the German general population. Two structural equation models were then used to examine the effects of elevated PCB levels on neuropsychological functions. Results suggest that participants who displayed increased PCB plasma levels continued to show impairments in verbal fluency but not in sensorimotor processing after a second examination one year after the first measurement. Specifically, low chlorinated PCBs are associated with impaired verbal fluency, as compared to high-chlorinated and dioxin-like congeners. Alteration of dopamine concentration in response to PCB exposure might be a potential explanation of this result.

Disposition and metabolomic effects of 2,2',5,5'-tetrachlorobiphenyl in female rats following intraperitoneal exposure

The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention. This study characterizes the distribution and metabolomic effects of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg/kg BW. PCB 52 exposure did not affect overall body weight. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis identified PCB 52 in all tissues investigated. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry (Nt-LCMS), were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Thus, the metabolism of PCB 52 and its effects on the metabolome must be considered in toxicity studies.

Disposition and Metabolomic Effects of 2,2',5,5'-Tetrachlorobiphenyl in Female Rats Following Intraperitoneal Exposure

The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention. This study characterizes the distribution and metabolomic effects of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg/kg BW. PCB 52 exposure did not affect overall body weight. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis identified PCB 52 in all tissues investigated. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry (Nt-LCMS), were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Thus, the metabolism of PCB 52 and its effects on the metabolome must be considered in toxicity studies.

Highlights

PCB 52 was present in adipose, brain, liver, and serum 3 weeks after PCB exposureLiver and serum contained hydroxylated, sulfated, and methylated PCB 52 metabolitesMetabolomics analysis revealed minor changes in endogenous serum metabolitesLevels of dopamine and its metabolites in the brain were not affected by PCB 52.

Para-occupational exposure to chemical substances: a systematic review

Today, many health problems related to work have overshadowed workers and their families. In the meantime, chemicals are among the risk factors that have created many problems due to para-occupational exposure. In para-occupational exposures, family members are exposed to work pollutants transferred to the home environment. This study was conducted to investigate para-occupational exposure to chemicals. To conduct this systematic review, databases such as "Web of Science", "Google Scholar", "Scopus", and "SID" were used. Relevant articles in these databases were extracted by searching keywords such as "take-home exposure", "para-occupational exposure", and "chemicals" from 2000 to 2022. To extract the required data, all parts of the articles were reviewed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA 2020). Among the 44 identified articles, 23 were selected as final articles, of which 10 were related to agriculture workers and their families, and 13 were related to other occupations. These studies mainly investigated para-occupational exposure to pesticides (14 studies) and metals (four studies). Also, contaminated work clothes, the washing place of contaminated clothes, and storage of working clothes, equipment, and chemicals were proposed as the main routes of contamination transmission. As a result of these para-occupational exposures, problems like neuro-behavioral disorders in children, end-stage renal disease, black gingival borders, and autism spectrum disorder were created or aggravated. Limiting the transmission routes and taking measures such as training and providing facilities like devoting places for washing and storing clothes in the workplaces can decrease this type of exposure.

Health risk assessment of polychlorinated biphenyls (PCBs) in baby clothes. A preliminary study

Clothes may contain a large range of chemical additives and other toxic substances, which may eventually pose a significant risk to human health. Since they are associated with pigments, polychlorinated biphenyls (PCBs) may be especially relevant. On the other hand, infants are very sensitive to chemical exposure and they may wear some contact and colored textiles for a prolonged time. Consequently, a specific human health risk assessment is required. This preliminary study was aimed at analyzing the concentrations of PCBs in ten bodysuits purchased in on-line stores and local retailers. The concentrations of 12 dioxin-like and 8 non-dioxin-like PCB congeners were determined by gas chromatography coupled to high resolution mass spectrometry, with detection limits ranging between 0.01 and 0.13 pg/g. The dermal absorption to PCBs of children at different ages (6 months, 1 year and 3 years old) was estimated, and the non-cancer and cancer risks were evaluated. Total levels of PCBs ranged from 74.2 to 412 pg/g, with a mean TEQ concentration of 13.4 pg WHO-TEQ/kg. Bodysuits made of organic cotton presented a total mean PCB concentration substantially lower than clothes made of regular cotton (11.0 vs. 15.8 pg WHO-TEQ/kg). The dermal absorption to PCBs for infants was calculated in around 3·10^-5 pg WHO-TEQ/kg·day, regardless the age. This value is > 10,000-fold lower than the dietary intake of PCBs, either through breastfeeding or food consumption. Furthermore, this exposure value would not pose any health risks for the infants wearing those bodysuits. Anyhow, as it is a very preliminary study, this should be confirmed by analyzing larger sets of textile samples. Further investigations should be also focused on the co-occurrence of PCBs and other toxic chemicals (i.e., formaldehyde, bisphenols and aromatic amines) in infant clothes.

Occupational exposure to polychlorinated biphenyls (PCBs) in workers at companies in the Colombian electricity sector

Polychlorinated biphenyls (PCBs) comprise a family of 209 congeners that have low electrical conductivity and high thermal resistance due to their physicochemical properties and are thus widely used as dielectric oils, among other applications. Although PCBs are no longer used in dielectric oils in Colombia as of several years ago, electric transformers in Colombia might still contain PCBs, and workers might carry PCBs due to exposure from when they were still used in dielectric fluid. Thus, occupational exposure in Colombia to PCBs was evaluated by determining their concentrations in the blood plasma samples of 115 workers in the electricity sector . The sum of the six PCB indicators was between <LOD and 16.09 µg L^-1 (median: <0.10 µg L^-1, 95^th percentile: 1.30 µg L^-1), and the total concentration of PCBs calculated as PCB 138 + 153 + 180 × 1.7 was between <LOD and 3210.17 ng g^-1 lipids (median: <7.30 ng g^-1 , 95^th percentile: 392.79 ng g^-1). . One worker dedicated to transformer and capacitor maintenance activities presented a PCB value higher than the biological tolerance level of 15 µg L^-1. The findings of the present investigation revealed that workers in the electricity sector face chronic occupational exposure to PCBs; Finally, the results can help to improve health policies related to these contaminants in the country.

Effects of Prepubertal Exposure to Aroclor-1221 on Reproductive Development and Transcriptional Gene Expression in Female Rats

Polychlorinated biphenyls (PCBs), as persistent organic pollutants, are environmental endocrine-disrupting chemicals (EDCs). We aim to investigate the effects of prepubertal exposure to PCBs on the reproductive development and expression and regulation of related genes in rats. Female rats were treated with Aroclor-1221 (A-1221) (4 mg/kg/day, 0.4 mg/kg/day) or castor oil daily from postnatal day (PND) 28 for 2 weeks by gavage. Morphological, histological, hormonal, and biochemical parameters were studied. Lower weight and relative weight of hypothalamus, earlier puberty onset, a longer length of the estrous cycle, lower serum estradiol and progesterone levels, accelerated ovarian folliculogenesis, and higher apoptotic index in the ovary were found. The in vitro fertilization study showed a lower fertilization rate and cleavage rate. The genetic study revealed higher expression of Kiss-1 mRNA and lower expression of GnRH mRNA in the hypothalamus and higher expression of AMH mRNA and lower expression of C-myc mRNA in the ovary. These confirmed the reproductive damage of A-1221 in rats.

Informal e-waste recycling and plasma levels of non-dioxin-like polychlorinated biphenyls (NDL-PCBs) - A cross-sectional study at Agbogbloshie, Ghana

Informal e-waste recycling leads to a contamination of the workers with several hazardous substances, in particular heavy metals and persistent organic pollutants (POPs). Polychlorinated biphenyls (PCBs) belong to the group of POPs and are suspected to be associated with adverse health effects. In particular lower chlorinated PCBs, such as the congeners PCB 28 and PCB 52 are a marker of occupational exposure. The aim of our study was to assess the occupational PCB exposure in e-waste workers in relation to their specific recycling task (e.g. dismantling, burning). Altogether, n = 88 e-waste workers and n = 196 control subjects have been included in this study. All plasma participant's samples were evaluated for the PCB congeners PCB 28, 52, 101, 138, 153, 180 and sum of NDL-indicator congeners by human biomonitoring. A significant difference could be detected for the lower chlorinated PCB congeners (PCB 28, 52, and 101) for e-waste workers in comparison to the control group. Analyzing specific recycling tasks, workers who dismantle and those who burn e-waste showed the highest plasma levels of PCB 28 and 52. In conclusion, e-waste workers showed occupational related elevated PCB levels. Although those levels did not exceed the BAT value, workers were contaminated with PCBs during their task. Occupational health and safety measure are therefore necessary to protect the worker's health.