Global Exposure to Per- and Polyfluoroalkyl Substances and Associated Burden of Low Birthweight.

Low birthweight (LBW) is a worldwide public health concern, while the global burden of LBW attributable to endocrine-disrupting chemicals, such as per- and polyfluoroalkyl substances (PFAS), has not yet been evaluated. Here, we established a large dataset for the biomonitoring of seven representative congeners of PFAS by examining data from 2325 publications. Global exposure to perfluorooctanesulfonic acid (PFOS) was the highest, followed by perfluorohexanesulfonic acid (PFHxS) and perfluorooctanoic acid (PFOA). Spatiotemporal exposure to PFAS varied considerably, with daily intake estimated in the range of 0.01-1.7 ng/kg/day. Moreover, decreasing trends in PFOS, PFHxS, and PFOA exposure were noted in most regions of the world over the past two decades, but such trends were not observed for other PFAS with long carbon chains, especially in East Asia. Furthermore, we estimated that human exposure to PFOA contributed to approximately 461,635 (95% confidence interval: 57,418 to 854,645) cases per year of LBW during the past two decades, predominantly from Asian regions. Although our estimation may be constrained by uncertainties from the dose-response curve and data availability, this study has unveiled that PFAS might be a contributor to global LBW prevalence during 2000-2019, supporting continuous actions to mitigate PFAS contamination.

Phthalate exposure and risk of diabetes mellitus: Implications from a systematic review and meta-analysis.

BACKGROUND: Epidemiologic studies indicated that phthalate exposure might be associated with diabetes mellitus (DM). However, discrepancies existed. The link between phthalate exposure and risk of DM remained unclarified. METHODS: We conducted a meta-analysis to explore the association between phthalate exposure and risk of DM. Effects of phthalate exposure on insulin resistance were also evaluated by systematic review. RESULTS: Seven studies involving 12,139 participants were included in this meta-analysis. Our results showed that urinary concentrations of phthalates were positively associated with risk of DM. The pooled ORs were 3.11 (95% CI: 1.16-8.37) for monomethyl phthalate (MMP), 1.27 (95% CI: 1.03-1.56) for mono-n-butyl phthalate (MnBP), 2.59 (95% CI: 1.10-6.10) for mono-isobutyl phthalate (MiBP), 1.99 (95% CI: 1.52-2.61) for mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), 1.90 (95% CI: 1.40-2.57) for mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), 1.55 (95% CI: 1.10-2.20) for mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), and 2.39 (95% CI: 1.18-4.85) for mono-(3-carboxypropyl) phthalate (MCPP), respectively. Molar summation of di-2-ethylhexyl phthalate metabolites (∑DEHP) was also found to be correlated with risk of DM (OR 2.15, 95% CI: 1.48-3.13). No significant association with risk of DM was found regarding monoethyl phthalate (MEP), monobenzyl phthalate (MBzP) and mono(2-ethylhexyl) phthalate (MEHP). In literature review, most studies showed positive correlations of phthalates, especially ∑DEHP, with homeostasis model assessment of insulin resistance and fasting glucose. CONCLUSION: Exposure to phthalates, especially MMP, MnBP, MiBP, MCPP and DEHP metabolites, might be a risk factor of DM. Our results should be interpreted with caution due to heterogeneous design of enrolled studies.

Human daily dietary intakes of antibiotic residues: Dominant sources and health risks.

Antibiotic use in crops is an emerging concern, however, human exposure to antibiotics residues through consumption of plant-derived food has generally been neglected. This study is a comprehensive evaluation based on full consideration of exposure sources and analysis for nearly 100 antibiotics. A total of 58 antibiotic compounds were detected in drinking water (n = 66) and 49 in food samples (n = 150) from Shenzhen, China. The probable daily intake from drinking water and food consumption based on the total concentration of all the detected antibiotic compounds was 310, 200, and 130 ng/kg-body weight/day for preschool children, adolescents, and adults, with a maximum of up to 1400, 970 and 530 ng/kg-bw/day, respectively. Consumption of plant-derived food products, rather than animal-derived food, was the main source of the daily intake, and drinking water was a minor source. Risk assessment suggested a potentially unacceptable health risk from daily intake of norfloxacin, lincomycin and ciprofloxacin. Further research is warranted to alleviate food safety concerns related to antibiotic residues in plant-derived and animal-derived food products.

Human health risk assessment of antibiotic resistance associated with antibiotic residues in the environment: A review.

The extensive use of antibiotics leading to the rapid spread of antibiotic resistance poses high health risks to humans, but to date there is still lack of a quantitative model to properly assess the risks. Concerns over the health risk of antibiotic residues in the environment are mainly (1) the potential hazard of ingested antibiotic residues in the environment altering the human microbiome and promoting emergence and selection for bacteria resistance inhabiting the human body, and (2) the potential hazard of creating a selection pressure on environmental microbiome and leading to reservoirs of antibiotic resistance in the environment. We provide a holistic view of health risk assessment of antibiotic resistance associated with antibiotic residues in the environment in contrast with that of the antibiotic resistant bacteria and discuss the main knowledge gaps and the future research that should be prioritized to achieve the quantitative risk assessment. We examined and summarized the available data and information on the four core elements of antibiotic resistance associated with antibiotic residues in the environment: hazard identification, exposure assessment, dose-response assessment, and risk characterization. The data required to characterize the risks of antibiotic residues in the environment is severely limited. The main future research needs have been identified to enable better assessments of antibiotic resistance associated with antibiotic residues in the environment: (1) establishment of a standardized monitoring guide of antibiotic residues and antibiotic resistance in the environment, (2) derivation of the relationship between antibiotic levels and pathogenic antibiotic-resistance development in different settings, and (3) establishment of the dose-response relationship between pathogenic antibiotic resistant bacteria and various infection diseases. After identification of key risk determinant parameters, we propose a conceptual framework of human health risk assessments of antibiotic residues in the environment. CAPSULE: A holistic view of human health risk assessment of antibiotic residues in the environment was provided.

Screening of Chlorinated Paraffins and Unsaturated Analogues in Commercial Mixtures: Confirmation of Their Occurrences in the Atmosphere.

Characterizing the detailed compositions of chlorinated paraffins (CPs) commercial mixtures is crucial to understand their environmental sources, fates, and potential risks. In this study, dichloromethane (DCM)-enhanced UPLC-ESI-QTOFMS analysis combined with characteristic isotope chlorine peaks is applied to screen all CPs and their structural analogues in the three most commonly produced CP commercial mixtures (CP-42, CP-52, and CP-70). Mass fractions of total short-chain CPs (SCCPs), medium-chain CPs (MCCPs) and long-chain CPs (LCCPs) ranged from 0.64 to 31.9%, 0.64 to 21.8%, and 0.04 to 43.9%, respectively, in the three commercial mixtures. 113 unsaturated SCCPs, MCCPs, and LCCPs were identified in the commercial mixtures. The detailed mass percentages of saturated and unsaturated CPs with carbon numbers of 10-30, chlorine numbers of 5-28, and unsaturated degrees of 0-7 were characterized in all commercial mixtures. Occurrences of the predominant saturated and unsaturated CPs were further confirmed in air samples collected in Guangdong Province, one of the major CP production areas in China, over one year. The profiles of the detected compounds indicated that LCCPs in air samples might come mainly from the production and usage of CP-52, and unsaturated C24-29-LCCPs were specifically originated from CP-70 used in the area.

Accumulation of polybrominated diphenyl ethers in breast milk of women from an e-waste recycling center in China.

Polybrominated diphenyl ethers (PBDEs) can be transferred to infants through the ingestion of breast milk, resulting in potential health risk. In this study, PBDEs, hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and 2,2',4,4',5,6'-hexachlorobiphenyl (CB-153) in human milk from women living adjacent to e-waste recycling sites of Wenling, China, were investigated. The median level of PBDEs in samples from residents living in the e-waste recycling environment >20years (R20 group, 19.5ng/g lipid weight (lw)) was significantly higher than that for residents living in Wenling <3years (R3 group, 3.88ng/g lw) (p<0.05), likely ascribable to specific exposure to PBDEs from e-waste recycling activities. In the R20 group, most congeners (except for BDE-209) were correlated with each other (p<0.05). Moreover, CB-153 showed significant association with most PBDE congeners, rather than BDE-209. The relationship indicated that most BDE congeners other than BDE-209 shared common sources and/or pathways with CB-153, e.g., dietary ingestion. The correlations between BDE-209 and other congeners were different in the two groups, likely suggesting their different exposure sources and/or pathways for PBDEs. Although estimated dietary intake of PBDEs for infants via breast milk was lower than the minimum value affecting human health, the PBDE exposure of infants should be of great concern because of their potential effect on the development of neonates over long-term exposure. OH-PBDEs were not detected in the collected samples, which is in accordance with reports in published literature, likely indicating that they were not apt to be accumulated in human milk.

Placental transfer of dechlorane plus in mother-infant pairs in an e-waste recycling area (Wenling, China).

It has been reported that breastfeeding can expose newborns to dechlorane plus (DP), but transplacental transfer of DP has not been documented. We measured DP and its dechlorinated analogs in matched maternal blood-placenta-cord blood samples from 72 residents of the e-waste recycling area of Wenling, China. DP was detected in cord sera, indicating the occurrence of prenatal DP exposure and the transfer of DP across the placenta. The concentration ratio in the cord serum and maternal serum was estimated to be 0.45 for syn-DP and 0.35 for anti-DP, indicating the placenta partially limited DP transfer with a greater extent for anti-DP. The DP concentrations in the maternal serum, placenta, and cord serum strongly correlated, indicating that DP could transfer between the tissues. The DP concentrations in the matched samples could be predicted from each other. The anti-DP/total DP concentration ratios in the placentas and cord sera were significantly different from those in the maternal sera, suggesting that DP stereoselectively bioaccumulates in human tissues. When the congener concentrations of polybrominated diphenyl ethers (PBDEs) were used as control variables, DP and total triiodothyronine concentrations were associated in the sera from mothers who had lived in Wenling for over 20 years.

Bioavailability and tissue distribution of Dechloranes in wild frogs (Rana limnocharis) from an e-waste recycling area in Southeast China.

Dechlorane Plus (DP), a flame retardant used as an alternative to decabromodiphenylether, has been frequently detected in organisms, indicating its bioaccumulation and biomagnification potential in aquatic and terrestrial species. However, little data is available on the bioaccumulation of DP in amphibians. Dechlorane Plus and its analogs (DPs) were detected in the liver, muscle and brain tissues of wild frogs (Rana limnocharis), which were collected from an e-waste recycling site, Southeast China. DP, Mirex, Dec 602 and a dechlorinated compound of DP (anti-Cl11-DP) varied in the range of 2.01-291, 0.650-179, 0.260-12.4, and not detected (nd)-8.67 ng/g lipid weight, respectively. No difference of tissue distribution was found for syn-DP, Mirex and Dec 602 between the liver and muscle tissue (liver/muscle concentration ratio close to 1, p > 0.05). However, higher retention was observed for anti-DP and anti-Cl11-DP in the frog muscle relative to the liver tissue (liver/muscle concentration ratio < 1, p < 0.05). Additionally, the blood-brain barrier was found to work efficiently to suppress these compounds entering brain tissues in this species (liver/brain concentration ratio > 1, p < 0.05), and the molecular weight was a key factor impacting the extent of the blood-brain barrier. Compared to levels in the muscle and brain tissue, a preferential enrichment of syn-DP was observed in the liver tissue, suggesting the occurrence of stereo-selective bioaccumulation in the wild frog.

Limits, challenges, and opportunities of sampling groundwater wells with plastic casings for microplastic investigations.

Investigating microplastics (MPs) in groundwater suffers from problems already faced by surface water research, such as the absence of common protocols for sampling and analysis. While the use of plastic instruments during the collection, processing, and analysis of water samples is usually avoided in order to minimize unintentional contamination, groundwater research encompassing MPs faces unique challenges. Groundwater sampling typically relies on pre-existing monitoring wells (MWs) and water wells (WWs) that are often constructed with polyvinyl chloride (PVC) casings or pipes due to their favorable price-performance ratio. Despite the convenience, however, the suitability of PVC casings for MP research is questionable. Unfortunately, the specifics of these wells are often not detailed in published studies. Current literature does not indicate significant pollution risks from PVC casings, suggesting these wells might still be viable for MP studies. Our preliminary analysis of the existing literature indicates that if PVC exceeds 6 % of the total MP concentration, it is likely that casings and pipes made of PVC are a source of pollution. Above this threshold, additional investigations in MWs and WWs with PVC casings and pipes are suggested.

Trace Analysis of Multiclass Antibiotics in Food Products by Liquid Chromatography-Tandem Mass Spectrometry: Method Development.

It is commonly known that the widespread use of antibiotics has led to their existence in food products as residues and ingestion of these food products may create a selection pressure on bacteria inhabiting the human body. In this study, an optimized method for the analysis of antibiotic residues in different food groups, including cereals, meat, eggs, milk, vegetables, and fruits, was developed using solvent extraction, solid-phase extraction cleanup, and liquid chromatography-mass spectrometry (LC-MS/MS). The limits of detection (LODs) were achieved as 0.007-1.1, 0.008-0.46, 0.002-0.67, 0.007-0.63, 0.001-0.098, and 0.005-0.26 ng/g in ng/g in cereals, meat, eggs, milk, vegetables, and fruits, respectively. The overall average recoveries at three spiking levels of the 81 antibiotics (5, 25, and 50 ng/g dry weight) were 82 ± 26, 77 ± 26, 70 ± 34, 69 ± 31, 73 ± 29, and 62 ± 37% in cereals, meat, eggs, milk, vegetables, and fruits, respectively. The method was then applied to the analysis of the targets in the collected wheat flour, mutton, chicken egg, boxed milk, cabbage, and banana samples, with the total concentration of the antibiotics detected being 4.4, 2.3, 36, 5.5, 2.7, and 14 ng/g, respectively. This work suggests that the developed method provides a time- and cost-effective method to identify and quantify antibiotic residues in common food products.

Association between phthalate exposure and risk of spontaneous pregnancy loss: A systematic review and meta-analysis.

Numerous studies suggested that phthalates might be associated with increased risk of spontaneous pregnancy loss. However, these results were conflicting and inconclusive. Thus we performed this systematic review and meta-analysis to assess the relationship between phthalate exposure and risk of pregnancy loss. We searched PubMed, EMBASE, Web of Science and major Chinese literature databases for studies investigating phthalates and spontaneous pregnancy loss. Pooled odds ratio (OR) with 95% confident interval (CI) were calculated for risk estimate. A total of 8 studies involving 4713 participants (including 651 cases and 4062 controls) were enrolled in the present meta-analysis. Our pooled results showed that spontaneous pregnancy loss was associated with higher urinary levels of monobutyl phthalate (MBP) (OR: 1.34, 95% CI: 1.04-1.72), mono(2-ethylhexyl) phthalate (MEHP) (OR: 1.57, 95% CI: 1.29-1.90), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) (OR: 1.59, 95% CI: 1.23-2.07) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) (OR: 1.47, 95% CI: 1.15-1.89). Indirect estimate of di-2-ethylhexyl phthalate (DEHP) levels, which were pooled from molar sum of urinary DEHP metabolites and hair DEHP, were also correlated with elevated risk of spontaneous pregnancy loss (OR: 1.79, 95% CI: 1.27-2.53). No significant association was found regarding urinary concentrations of monomethyl phthalate (MMP), monoethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP) or mono(2-ethyl-5-carboxypentyl) phthalate (MECPP). Our findings indicate that phthalate exposure might be a risk factor for spontaneous pregnancy loss. Given indirect estimate of phthalate exposure by evaluating its metabolite levels, our results should be interpreted with caution.

High inter-species differences of 12378-polychlorinated dibenzo-p-dioxin between humans and mice.

Although huge interspecies differences in the response to dioxins have been acknowledged, toxic equivalency factors derived from rodent studies are often used to assess human health risk. To determine interspecies differences, we first developed a toxicokinetic model in humans by measuring dioxin concentrations in environmental and biomonitoring samples from Southern China. Significant positive correlations between dioxin concentrations in blood and age were observed for seven dioxin congeners, indicating an age-dependent elimination rate. Based on toxicokinetic models in humans, the half-lives of 15 dioxin congeners were estimated to be 1.60-28.55 years. In consideration that the highest contribution to total toxic equivalency in blood samples was by 12378-polychlorinated dibenzo-p-dioxin (P5CDD), this study developed a physiologically based pharmacokinetic (PBPK) model of 12378-P5CDD levels in the liver, kidney, and fat of C57/6J mice exposed to a single oral dose, and the half-life was estimated to be 26.1 days. Based on estimated half-lives in humans and mice, we determined that the interspecies difference of 12378-P5CDD was 71, much higher than the default usually used in risk assessment. These results could reduce the uncertainty human risk assessment of 12378-P5CDD, and our approach could be used to estimate the interspecies differences of other dioxin congeners.

Efficient detection and assessment of human exposure to trace antibiotic residues in drinking water.

Human exposure to antibiotic residues in drinking water has not been well evaluated. This study is the first attempt to simultaneously and efficiently identify and quantify 92 antibiotic residues in filtered tap water (multistage filtration at the tap) (n = 36) collected from 10 areas of a large city in southern China, 10 Chinese brands of bottled/barreled water (n = 30) and six foreign brands of bottled water (n = 18) obtained from the Chinese market. The average and median concentrations of all the detected antibiotic compounds was 182 and 92 ng/L in filtered tap water, 180 and 105 ng/L in Chinese brands of bottled/barreled water, and 666 and 146 ng/L in foreign brands of bottled water, respectively. A total of 58 antibiotics were detected in the filtered tap water, and 45 and 36 antibiotics were detected in the Chinese and foreign brands of bottled water, respectively. More types of antibiotics were detected in Chinese brands of bottled water than in the other bottled waters. In addition, Chinese waters had high roxithromycin concentrations, while the foreign brands of bottled water had high concentrations of dicloxacillin. The average and median values of the estimated overall daily intake of all the detected antibiotics were 4.3 and 2.3 ng/kg/day when only filtered tap water was drunk, 4.0 and 2.5 ng/kg/day when Chinese brands of bottled water was drunk, and 16.0 and 4.9 ng/kg/day when foreign brands of bottled water was drunk. Further study is needed to develop a more comprehensive estimation of human exposure to antibiotic residues in the environment and a more in-depth understanding of the potential hazard of ingested antibiotic residues to the human microbiome.

Age-dependent human elimination half-lives of dioxin-like polychlorinated biphenyls derived from biomonitoring data in the general population.

Constant elimination half-life is usually used in first-order one-compartment pharmacokinetic models to assess human exposure to dioxin-like polychlorinated biphenyls (PCBs). However, hepatic clearance rates are usually lower for elders than for young people. In this study, levels of 12 dioxin-like PCBs were determined in blood samples collected in 2012 from 305 individuals from the general population. We estimated the historical daily intake of dioxin-like PCBs for individuals with a validated annual exponential decay function. Based on the blood levels and historical daily intake levels, and using the maximum likelihood estimation by running the first-order one-compartment pharmacokinetic model, elimination rates were optimized as exponential functions of age for PCB118, PCB157, PCB189 and PCB126; linear functions of age for PCB114, PCB123, PCB167 and PCB169; and constant functions of age for PCB105 and PCB156. With the exception of PCB105 and PCB156, half-lives generally increased with age for individuals from 24 to 50 years old: from 0.805 to 1.95 years for PCB189, 2.08-4.54 years for PCB157, 3.32-5.58 years for PCB126, 3.52-6.81 years for PCB123, 5.24-12.29 years for PCB169, 6.60-14.40 years for PCB114, 7.50-14.01 years for PCB118, and 9.97-21.97 years for PCB167. The half-lives of PCB105 (5.79 years) and PCB156 (15.1 years) were independent of age. Our research for the first time clarified the effects of age on the elimination rate of dioxin-like PCBs in individuals from the general population, thus reducing uncertainty in future health risk assessments.

A spatio-temporally weighted hybrid model to improve estimates of personal PM2.5 exposure: Incorporating big data from multiple data sources.

An accurate estimation of population exposure to particulate matter with an aerodynamic diameter <2.5 µm (PM2.5) is crucial to hazard assessment and epidemiology. This study integrated annual data from 1146 in-home air monitors, air quality monitoring network, public applications, and traffic smart cards to determine the pattern of PM2.5 concentrations and activities in different microenvironments (including outdoors, indoors, subways, buses, and cars). By combining massive amounts of signaling data from cell phones, this study applied a spatio-temporally weighted model to improve the estimation of PM2.5 exposure. Using Shanghai as a case study, the annual average indoor PM2.5 concentration was estimated to be 29.3 ±â€¯27.1 µg/m3 (n = 365), with an average infiltration factor of 0.63. The spatio-temporally weighted PM2.5 exposure was estimated to be 32.1 ±â€¯13.9 µg/m3 (n = 365), with indoor PM2.5 contributing the most (85.1%), followed by outdoor (7.6%), bus (3.7%), subway (3.1%), and car (0.5%). However, considering that outdoor PM2.5 makes a significant contribution to indoor PM2.5, outdoor PM2.5 was responsible for most of the exposure in Shanghai. A heatmap of PM2.5 exposure indicated that the inner-city exposure index was significantly higher than that of the outskirts city, which demonstrated that the importance of spatial differences in population exposure estimation.

Using big data from air quality monitors to evaluate indoor PM2.5 exposure in buildings: Case study in Beijing.

Due to time- and expense- consuming of conventional indoor PM2.5 (particulate matter with aerodynamic diameter of less than 2.5 µm) sampling, the sample size in previous studies was generally small, which leaded to high heterogeneity in indoor PM2.5 exposure assessment. Based on 4403 indoor air monitors in Beijing, this study evaluated indoor PM2.5 exposure from 15th March 2016 to 14th March 2017. Indoor PM2.5 concentration in Beijing was estimated to be 38.6 ±â€¯18.4 µg/m3. Specifically, the concentration in non-heating season was 34.9 ±â€¯15.8 µg/m3, which was 24% lower than that in heating season (46.1 ±â€¯21.2 µg/m3). A significant correlation between indoor and ambient PM2.5 (p < 0.05) was evident with an infiltration factor of 0.21, and the ambient PM2.5 contributed approximately 52% and 42% to indoor PM2.5 for non-heating and heating seasons, respectively. Meanwhile, the mean indoor/outdoor (I/O) ratio was estimated to be 0.73 ±â€¯0.54. Finally, the adjusted PM2.5 exposure level integrating the indoor and outdoor impact was calculated to be 46.8 ±â€¯27.4 µg/m3, which was approximately 42% lower than estimation only relied on ambient PM2.5 concentration. This study is the first attempt to employ big data from commercial air monitors to evaluate indoor PM2.5 exposure and risk in Beijing, which may be instrumental to indoor PM2.5 pollution control.

Exposure assessment of PCDD/Fs for the population living in the vicinity of municipal waste incinerator: Additional exposure via local vegetable consumption.

While the exposure assessment of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/Fs) for people living in the vicinity of municipal solid waste incinerators (MSWI) has been investigated, indirect exposure to MSWI-emitted PCDD/Fs via consumption of local foods has not been well assessed. In this study, the PCDD/F concentration in the local vegetables grown near a MSWI located in Shenzhen, South China, was determined to be 0.92 ± 0.59 pg/g wet weight (ww), significantly higher than that (0.25 ± 0.35 pg/g ww) in commercial vegetables (p < 0.05). The PCDD/F concentrations in Banyan leaf (Ficus microcarpa) samples collected from 5 sampling sites at 1 km intervals from the MSWI were found to be significantly decreased with increasing distance, suggesting that the local plants would be impacted by emissions from the MSWI. The exposure assessment of PCDD/Fs for the population living in the vicinity of MSWI was carried out by simultaneously analyzing PCDD/Fs in other food groups that were commonly consumed by the residents. If only the local vegetables were consumed and other foods were acquired commercially, the total dietary intake for a general adult was 0.94 ± 0.41 pg TEQ/kg bw/day, of which consumption of local vegetables accounted for 52.3%. If all foods consumed including vegetables were from a commercial source, the total dietary intake was 0.56 ± 0.30 pg TEQ/kg bw/day, of which consumption of commercial vegetables accounted for 20.1%. The present study for the first time reported the additional human exposure to PCDD/Fs via consumption of local vegetables impacted by emissions from MSWI.

Relative importance of different exposure routes of heavy metals for humans living near a municipal solid waste incinerator.

The potential health effects of toxic chemicals (e.g. heavy metals) emitted by municipal solid waste incinerators (MSWIs) are of great concern to local residents, however there have been few studies on the contributions of different exposure pathways and their subsequent effects on the body burden of residents living near MSWIs. In this study, multiple exposure routes of heavy metals including Pb, Cr, Cd and Mn were assessed by investigating the metals in foods (such as vegetables, crops, meats and fruits etc.), drinking water, ambient air and soil collected surrounding an MSWI in Shenzhen, south China. Vegetable ingestion played the most important role in the total average daily dose of Pb and Cr, and cereals were the key exposure routes for Mn and Cd. Compound-specific contaminations were observed in the investigated areas, with Pb and Cr present in the surrounding environment, having accumulated to relatively high levels in the local vegetables, and the intake of contaminated vegetable foods greatly influencing the body burden of Pb and Cr. Consistently, significantly high blood concentrations of Pb and Cr were detected in the local residents compared to a referenced population, and a lack of significant differences was found for Cd and Mn. The results possibly suggested that emission of MSWI influenced the external exposure doses of the major pathways of Pb and Cr in this study, and resulted in the different body burden of metals in humans living near a MSWI. MSWI-local food-humans is an important exposure pathway for residents living near MSWI, and thus should not be neglected in developing future strategies and policies to prevent the high risks suffered by residents living near MSWIs.

Bioaccumulation characteristics of polybrominated diphenyl ethers in the marine food web of Bohai Bay.

In recent years, polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants, but its bioaccumulation and debromination in biota have remained largely unclear. In this study, we analyzed six PBDEs (BDE47, 99, 100, 153, 154, and 209) in various tissues (i.e., viscera, muscle, and gill) of 11 types of marine organisms including zooplankton, invertebrate and fish. The concentrations of six PBDE including BDE209 in marine organisms ranged from 0.75 to 7.29 ng/g dry weight, BDE209 from 0.46 to 6.78 ng/g dry weight, respectively. BDE209 was the dominant congener in all samples, followed by BDE47. The concentration ratio of BDE47, 99, 154 to ΣPBDEs in various tissues of organisms (i.e., Rapana venosa, shrimp, crab, cuttlefish, octopus, Synechogobius hasta, tonguefish and wolfish) increased, while the concentration ratio of BDE209 to ΣPBDEs decreased. Large differences of the concentration ratios between BDE99 and BDE100 in tissues of crab was found, ranging from 32:68 in crab viscera to 83:17 in crab leg muscle. Biomagnification factors for individual PBDE congeners ranged from 0.16 to 78.6. In general, the BMFs for BDE209 in muscle were higher than those in viscera within feeding relationships. The study results suggesting BDE209 can be biodegraded to BDE47 through BDE154 and BDE99 in marine organism, its metabolite importantly influenced by organism type not trophic level; higher percentage of BDE154 was found in viscera than that in other tissues in the analyzed marine organisms of Bohai Bay.

Dechlorane Plus and its dechlorinated analogs from an e-waste recycling center in maternal serum and breast milk of women in Wenling, China.

We measured Dechlorane Plus (DP) and its dechlorinated analogs in the blood and milk from women living in e-waste recycling sites in Wenling of Taizhou region, China (n = 49). Both syn-DP and anti-DP were detected in all samples. Another compound, Cl(11)-DP, was detected in 45% and 84% of milk and serum samples, respectively. DP levels in blood and milk from residents living in the local environment >20 yrs (R(20) group) were significantly higher than those living in Taizhou <3 yrs (R(3) group) (p < 0.05). The milk/serum partition coefficient from the same women was approximately 0.43 and 0.47 for syn-DP and anti-DP, respectively. A similar value in milk compared with anti-DP/∑DPs (f(anti)) in serum suggested that stereoselective DP bio-accumulation did not occur during the DP transport from blood to milk. This result indicate that DP can bio-accumulate in blood and milk with the low milk/serum partition coefficient and similar blood and milk stereoselective bio-accumulation profiles.