Multicenter biomonitoring of polybrominated diphenyl ethers (PBDEs) in colostrum from China: Body burden profile and risk assessment

Bisphenol chemicals in colostrum from Shanghai, China during 2006-2019: Concentration, temporal variation, and potential influence on birth parameters

Bisphenol A (BPA) and its alternatives bisphenol S (BPS) and bisphenol F (BPF) are identified as endocrine disruptors that have negative impacts on infant growth. Their temporal variations in human milk and potential effects on fetal growth are not well known. In this study, colostrum collecting at four time points between 2006 and 2019 and paired urine in 2019 from Shanghai, China, were analyzed for eight bisphenols. The total concentrations in colostrum in 2019 were up to 3.43 ng/mL, with BPA being dominant, followed by BPS and BPF. BPA levels in colostrum noticeably decreased from 2010 to 2013. Additionally, obvious percentage changes in bisphenols were observed in 2019. The BPA concentrations in paired colostrum and urine were not significantly correlated. High levels of BPA in colostrum were linked to a significant reduction in birth head circumference in 2019 (p = 0.031). BPA and BPS in colostrum might have similar negative effect on fetal growth in 2019, but these effects were generally non-significant. Further studies are needed to testify the potential impact. The hazard indexes for infants in the first week of life were below 1, suggesting no obvious health risks. However, the high contribution from BPA still warrants further attention.

Has Regulatory Action Reduced Human Exposure to Flame Retardants?

Flame retardant (FR) exposure has been linked to several environmental and human health effects. Because of this, the production and use of several FRs are regulated globally. We reviewed the available records of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDDs) in human breast milk from literature to evaluate the efficacy of regulation to reduce the exposure of FRs to humans. Two-hundred and seven studies were used for analyses to determine the spatial and temporal trends of FR exposure. North America consistently had the highest concentrations of PBDEs, while Asia and Oceania dominated HBCDD exposure. BDE-49 and -99 indicated decreasing temporal trends in most regions. BDE-153, with a longer half-life than the aforementioned isomers, typically exhibited a plateau in breast milk levels. No conclusive trend could be established for HBCDD, and insufficient information was available to determine a temporal trend for BDE-209. Breakpoint analyses indicated a significant decrease in BDE-47 and -99 in Europe around the time that regulation has been implemented, suggesting a positive effect of regulation on FR exposure. However, very few studies have been conducted globally (specifically in North America) after 2013, during the time when the most recent regulations have been implemented. This meta-analysis provides insight into global trends in human exposure to PBDEs and HBCDD, but the remaining uncertainty highlights the need for ongoing evaluation and monitoring, even after a compound group is regulated.

Prenatal exposure to phthalates and polybrominated diphenyl ethers on neonatal health: A birth cohort study in Guangxi, China

Few epidemiological studies have focused on prenatal phthalates (PAEs) and polybrominated diphenyl ethers (PBDEs) exposure to neonatal health in China. This study aimed to assess the associations between prenatal PAEs and PBDEs exposure and neonatal health in Guangxi, a Zhuang autonomous region of China. Concentrations of 4 PAEs metabolites (mPAEs) and 5 PBDEs congeners were measured in the serum of 267 healthy pregnant women. Birth outcomes and clinical data of neonates were collected after delivery. Mono-(2-Ethylhexyl) phthalate (MEHP) (81.52%) and BDE47 (35.21%) were the mPAEs and PBDEs congeners with the highest detection rate in serum. Prenatal exposures to mono-n-butyl phthalate (MBP), MEHP, and ΣmPAEs were negatively associated with birth weight (BW), birth length (BL), and gestational age (GA). Higher exposures to MBP, MEHP, and ΣmPAEs were associated with an increased odds ratio (OR) for low birth weight (LBW), but exposure to BDE28 exhibited the opposite effect. Moreover, higher exposures to MBP, MEHP, ΣmPAEs, BDE99, and ΣPBDEswere associated with an increased OR for premature birth (PTB) (P < 0.05). In contrast to MBP exposure, BDE28 exposure was associated with a higher OR for neonatal jaundice (NNJ) (P < 0.05). The interaction analysis showed a positive interaction between monoethyl phthalate (MEP) and BDE28 on the risk of NNJ and positive interaction between ΣmPAEs and BDE47 on the risk of NNJ. In addition, there are ethnicity-specific associations of prenatal PBDEs exposure with neonatal health in individuals of Zhuang and Han nationalities, and boy neonates were more sensitive to prenatal PBDEs exposure than girl neonates. The results revealed that prenatal exposure to mPAEs and PBDEs might have adverse effects on neonatal development, and the effects might be ethnicity- and sex-specific.

Assessment of polybrominated diphenyl ether contamination and associated human exposure risk at municipal waste dumping sites

The reports concerning the occurrence and fate of polybrominated diphenyl ethers (PBDEs) at municipal solid waste (MSW) dumping sites are scarce, and considering the Indian context, no study has been conducted to assess PBDE contamination at MSW dumping sites and associated exposure and health risk. Therefore, in the present study, the concentration of PBDE congeners was investigated in soil samples amassed from MSW dumping sites of India and the factors affecting the dissemination of different PBDE congeners in soil were evaluated. Also, the human exposure and health risk through soil intake and dermal contact were also evaluated the first time in India. The total PBDE concentrations from tri- to deBDE congeners in soil ranged from 6.81 to 33.67 μg/g dw and showed a trend towards higher levels of PBDEs in the dumping sites of more populous cities. BDE 183 was found to be the main congener in the soil of the dumping sites. The congener profile in the soil exhibited the composition of the octa- and deBDE technical mixture and possibilities of biological and photodegradation of deBDE into lower brominated congeners. A significant correlation was observed between the measures of BDE 183 and BDE 209 congeners and carbon, nitrogen and hydrogen contents of the soil. The measured exposure doses of PBDEs through soil intake and dermal contact and the hazard index was estimated higher in children as compared to adults, which indicates the increased risk and susceptibility of infants and children to PBDE exposure. The results of the present study revealed that the MSW dumping sites in India are a sink of PBDEs and might have detrimental effects on human health.

Spatial monitoring and health risk assessment of polybrominated diphenyl ethers in environmental matrices from an industrialized impacted canal in South Africa

This study investigates the pollution of Markman stormwater runoff, which is a tributary to Swartkops River Estuary. Solid-phase and ultrasonic extraction methods were utilized in the extraction of water and sediment samples, respectively. The pH of the sampling sites was above the EU guideline. The ranges of concentration of [Formula: see text]PBDE obtained in water and sediment samples for all the seasons were 58.47-1357 ng/L and 175-408 ng/g, respectively. Results also showed that BDE-66 was the dominant congener, specifically in the industrial zone, where its concentrations ranged from 2 to 407 ng/g in sediment. Consequently, the high concentration of BDE- 66 in the sediment of stormwater calls for concern. Penta-BDE suggests potential moderate eco-toxicological risk, as evident in the calculated risk assessment. The result showed possible photodegradation along the contaminant's travel time, as only 7% of the PBDE was detected at the point of entry into the Swartkops River Estuary. Markman stormwater may be contributing heavily to the pollution load of Swartkops River, as evident in the alarming concentrations of PBDEs obtained. The industries at this zone should eliminate the contaminants before discharging their effluents into the canal.

Association of prenatal exposure to polybrominated diphenyl ethers at low levels with adiposity measures in children up to 6 years

The effects of prenatal PBDEs exposure, especially at low levels, on childhood obesity are scarce. No previous studies have investigated the effect modification by breastfeeding on the associations of PBDEs exposure with childhood obesity. We aimed to investigate the associations of prenatal PBDEs exposure with adiposity measures in children up to 6 years, and the effect modification by breastfeeding. Participants were mother-child pairs from the Shanghai-Minhang Birth Cohort study. Nine PBDE congeners were assessed in cord blood plasma. We obtained information about child weight (0-6 years), height (0.5-6 years), arm circumference (0-6 years), and waist circumference (0-6 years) at each follow-up visit. Breastfeeding duration was collected when children were aged 1 year and was categorized as short (≤6 months) and adequate (>6 months). Multiple linear regression models were used to examine the associations of PBDE concentrations with adiposity measures of the children at each age. Generalized estimating equation (GEE) models were used to estimate the overall associations of PBDEs exposure with adiposity measures. We examined the effect modification by breastfeeding using stratified analyses and by including interaction terms into GEE models. For boys, there was a general profile of positive associations of several PBDE congeners exposure with adiposity measures. Especially, boys with higher BDE-153 concentration had higher adiposity measures at each time point. For girls, we also found positive associations of BDE-100 and -153 exposure with adiposity measures. The GEE models showed consistent patterns for BDE-153 in boys and for BDE-100 and -153 in girls. In breastfeeding-stratified analyses, stronger associations of PBDEs exposure with adiposity measures were generally found in children who were shortly breastfed. Our findings suggest that prenatal exposure to PBDEs at low levels may influence childhood adiposity measures, and the potential effects of PBDEs were attenuated by adequate breastfeeding.

Effects of Polybrominated Diphenyl Ethers on Hormonal and Reproductive Health in E-Waste-Exposed Population: A Systematic Review

Electronic waste management is a global rising concern that is primarily being handled by informal recycling practices. These release a mix of potentially hazardous chemicals, which is an important public health concern. These chemicals include polybrominated diphenyl ethers (PBDEs), used as flame retardants in electronic parts, which are persistent in nature and show bioaccumulative characteristics. Although PBDEs are suspected endocrine disruptors, particularly targeting thyroid and reproductive hormone functions, the relationship of PBDEs with these health effects are not well established. We used the Navigation Guide methodology to conduct a systematic review of studies in populations exposed to e-waste to better understand the relationships of these persistent flame retardants with hormonal and reproductive health. We assessed nineteen studies that fit our pre-determined inclusion criteria for risk of bias, indirectness, inconsistency, imprecision, and other criteria that helped rate the overall evidence for its quality and strength of evidence. The studies suggest PBDEs may have an adverse effect on thyroid hormones, reproductive hormones, semen quality, and neonatal health. However, more research is required to establish a relationship of these effects in the e-waste-exposed population. We identified the limitations of the data available and made recommendations for future scientific work.

Human Biomonitoring Data in Health Risk Assessments Published in Peer-Reviewed Journals between 2016 and 2021: Confronting Reality after a Preliminary Review

Human biomonitoring (HBM) is a rapidly developing field that is emphasized as an important approach for the assessment of health risks. However, its value for health risk assessment (HRA) remains to be clarified. We performed a review of publications concerned with applications of HBM in the assessment of health risks. The selection of publications for this review was limited by the search engines used (only PubMed and Scopus) and a timeframe of the last five years. The review focused on the clarity of 10 HRA elements, which influence the quality of HRA. We show that the usage of HBM data in HRA is limited and unclear. Primarily, the key HRA elements are not consistently applied or followed when using HBM in such assessments, and secondly, there are inconsistencies regarding the understanding of fundamental risk analysis principles and good practices in risk analysis. Our recommendations are as follows: (i) potential usage of HBM data in HRA should not be non-critically overestimated but rather limited and aligned to a specific value for exposure assessment or for the interpretation of health damage; (ii) improvements to HRA approaches, using HBM information or not, are needed and should strictly follow theoretical foundations of risk analysis.

Occurrence and Risk Assessment of Polybrominated Diphenyl Ethers in Surface Water and Sediment of Nahoon River Estuary, South Africa

The concentrations, potential sources, and compositional profile of PBDEs in the surface water and sediment of Nahoon Estuary, East London, South Africa, were investigated with solid-phase extraction and ultra-sonication, respectively, followed by gas-chromatography-electron capture detection. The seasonal range of the contaminants’ concentrations in water and sediment samples in spring season were ∑PBDE 329 ± 48.3 ng/L (25.32–785 ng/L) and ∑PBDE 4.19 ± 0.35 ng/g dw (1.91–6.57 ng/g), but ∑PBDE 62.1 ± 1.50 ng/L (30.1–110 ng/L) and ∑PBDE 65.4 ± 15.9 ng/g dw (1.98–235 ng/g) in summer, respectively. NH1 (first sampling point) was the most contaminated site with PBDE in the Estuary. The potential source of pollution is attributed to the stormwater runoff from a creek emptying directly into the Estuary. This study’s dominant PBDE congener is BDE-17, ranging from below detection limit to 247 ng/L and 0.14–32.1 ng/g in water and sediment samples, respectively. Most detected at all the sites were BDE-17, 47, 66, and 100. Most BDE-153 and 183 are found in sediment in agreement with the fact that higher brominated congeners of PBDE adsorb to solid materials. There was no correlation between the congeners and organic carbon and organic matter. However, the human health risk assessment conducted revealed that the PBDE concentration detected in the estuary poses a low eco-toxicological risk. Nevertheless, constant monitoring should be ensured to see that the river remains safe for the users, as it serves as a form of recreation to the public and a catchment to some neighbourhoods.

Polychlorinated biphenyls (PCBs) in the colostrum samples from the Yangtze River Region: Exposure profile and risk assessment

Polychlorinated biphenyls (PCBs) may transfer into the neonates through the placental transfer and via breastfeeding after the delivery, thus might be harmful to the infant. Sixty colostrum samples in the Yangtze River Region were collected to investigate the concentration, distribution pattern, and enantiomer characteristic of the PCB exposure. Among all samples, over 90% of pollutants were tetra-to hepta-chlorinated PCBs. The sum concentration of the PCB was 512 (IQR: 322-856) ng g^-1 lipid weight. Enantiomer fraction (EF) of PCB 95 and PCB 149 was found lower than the racemic value, while EFs of PCB 45 and PCB 136 were found higher and near-racemic state, respectively. The concentration pattern and enantiomeric properties of the PCBs indicated that the mothers from Mianyang had a recent exposure to PCBs. Among all samples, similar exposure and metabolic pathways of the PCB congeners were observed. PCB exposure showed no significant correlation with the birth outcome of the infants, but 43.3% of the infants have potential health risks via breastfeeding.

Assessment of polybrominated diphenyl ethers and emerging brominated flame retardants in Pheretima (a Traditional Chinese Medicine): Occurrence, residue profiles, and potential health risks

China produces and consumes large quantities of brominated flame retardants (BFRs) as well as several other unregulated electronic waste recycling activities, causing high BFR concentrations in the natural environment. Thus, Traditional Chinese Medicines (TCMs) may be contaminated by legacy BFRs (e.g. polybrominated diphenyl ethers (PBDEs)) and emerging BFRs (eBFRs, such as decabromodiphenyl ethane (DBDPE)) during growth, processing, packaging, and transportation. Pheretima, which is a typical animal drug recorded in Chinese Pharmacopoeia, was used as an example to evaluate human exposure to BFRs through TCM intake. This study is the first to determine 25 PBDEs and 5 eBFRs in Pheretima and estimate the daily BFR intake via Pheretima-containing TCMs. Twenty-seven Shanghai Pheretima and fifty-one Guang Pheretima samples were collected between March and June 2019 in southeast China. High BFR detection frequencies were found in Pheretima, of which BDE-209 and DBDPE were the most predominant analytes. The total PBDE contents ranged from 73 pg/g to 8,725 pg/g, while that of the eBFRs varied between 115 pg/g and 2,824 pg/g. The profiles and abundances were found to be species- and origin-dependent. However, the traditional processing of Pheretima may reduce BFR residues. Based on the usual clinical doses of Pheretima and the available chronic oral reference doses of BDE-47, 99, 153, and 209, the mean (95th percentile) of the total hazard quotient was estimated to be 9.1 × 10^-5 (2.7 × 10^-4). Therefore, there is little risk related to BFR exposure for patients taking formulated Pheretima-containing TCMs. However, it is necessary to establish routine monitoring programs for the co-existence of pollutants in TCMs to perform a systematic and comprehensive risk assessment.

Levels of polybrominated diphenyl ethers in Brazilian food of animal origin and estimation of human dietary exposure

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants, commonly used as flame retardants in a wide variety of products. In the last years, the concentration of PBDEs is increasing in the environment, turning human exposure more common. Since the diet is the primary source of human exposure, several surveys evaluate the levels of PBDEs in foods to estimate the dietary intake and the hazard index (HI). However, this data is limited in Brazil. Thus, this study aims to determine the level of seven PBDE congeners (BDE-28, 47, 99, 100, 153, 154, 183) in Brazilian food of animal origin. The total concentration of PBDE (∑PBDE) determined in the food samples were 2.29 (0.92-4.85) ng/g wet weight (ww), 1.98 (1.23-3.12) ng/g ww, 1.91 (1.23-3.12) ng/g ww, and 4.42 (1.26-8.42) ng/g ww in eggs, fish, seafood, and milk, respectively. BDE-47 was the most abundant compound. Based on consumer habits and the found levels of PBDEs in Brazilian food, we estimated the daily intake of ∑PBDEs as 3.25 (0.02-2.19) ng/kg bw per day. Surprisingly, the PBDE levels in milk samples were higher than those found in reported studies in other countries, and the consumption of milk products give a higher relative contribution to PBDEs exposure. The HI was <1. A complete risk assessment of the human exposure to PBDEs most likely could be evaluated considering all commercial PBDEs congeners and other exposure sources of these contaminants.

Exposure pathways, levels and toxicity of polybrominated diphenyl ethers in humans: A review

Polybrominated diphenyl ethers (PBDEs) are extensively used as brominated flame retardants (BFRs) in different types of materials, which have been listed as Persistent Organic Pollutants (POPs) by the Stockholm Convention in 2009 and 2017. Due to their ubiquities in the environment and toxicities, PBDEs have posed great threat to both human health and ecosystems. The aim of this review is to offer a comprehensive understanding of the exposure pathways, levels and trends and associated health risks of PBDEs in human body in a global scale. We systematically reviewed and described the scientific data of PBDE researches worldwide from 2010 to March 2020, focusing on the following three areas: (1) sources and human external exposure pathways of PBDEs; (2) PBDE levels and trends in humans; (3) human data of PBDEs toxicity. Dietary intake and dust ingestion are dominant human exposure pathways. PBDEs were widely detected in human samples, especially in human serum and human milk. Data showed that PBDEs are generally declining in human samples worldwide as a result of their phasing out. Due to the common use of PBDEs, their levels in humans from the USA were generally higher than that in other countries. High concentrations of PBDEs have been detected in humans from PBDE production regions and e-waste recycling sites. BDE-47, -153 and -99 were proved to be the primary congeners in humans. Human toxicity data demonstrated that PBDEs have extensively endocrine disruption effects, developmental effects, and carcinogenic effects among different populations.

Indoor polybrominated diphenyl ethers in urban China: An exposure and risk assessment based on settled dust from selected urban regions

In this study, measurements of seven typical polybrominated diphenyl ethers (PBDEs) in indoor settled dust were summarized in selected urban regions of China. BDE-209 was the most dominant congener in settled dust (1.4-101 μg/g), with a mean contribution of 95%. Indoor exposures to PBDEs were estimated via inhalation, dust ingestion, and dermal absorption. The average daily intake of ΣPBDE was 4.9 to 19.1 ng/day/kg for all the population groups, with >80% of the total exposures from dust ingestion. Exposures in commuting environments (contributing 60%-80% of the total exposures) were higher than those in other microenvironments. The means of hazard indexes ranged from 1.66 × 10^-3 to 5.26 × 10^-3, which were mainly as a result of exposure to BDE-209, BDE-47, and BDE-99. The average lifetime cancer risks were from 0.03 × 10^-9 to 2.37 × 10^-9, which indicated the acceptable health risks resulting from indoor PBDE exposure for the Chinese population. The present study could provide valuable information that could be helpful for decision-makers, analysts and researchers to develop, implement and evaluate the effectiveness of interventions for the reduction of exposures to semi-volatile organic compounds (SVOCs) for large population groups in China.