E-waste Dismantling Site Research Articles

Occurrence, Concentration Characteristics and Vertical Distribution of PCDD/Fs in Soil Around a N e-Waste Dismantling Site

Occurrence, Concentration Characteristics and Vertical Distribution of PCDD/Fs in Soil Around a N e-Waste Dismantling Site

Polybrominated Diphenyl Ether in E-waste Dismantling Sites in Taizhou City, Zhejiang Province: Concentration, Distribution, and Migration Trend

The concentration of polybrominated biphenyl ethers (PBDEs) in surface soil and atmosphere of e-waste dismantling sites in Taizhou city, Zhejiang Province was determined. The concentration ranges of ∑12PBDEs in surface soil of e-waste dismantling site, farmland, and resident areas in Fengjiang Town (FJ) and Binhai Town (BH) were 21.8-1310 ng ·g-1 and 6.19-220 ng ·g-1, respectively. No significant difference was observed in the distribution of PBDEs between the FJ and BH soil. The concentration range of ∑12PBDEs in the atmosphere of FJ and BH were 262-3240 pg ·m-3 and 840-2990 pg ·m-3, respectively. The median levels of PBDEs in the atmosphere of FJ and BH were 1410 pg ·m-3 and 840 pg ·m-3 in winter and 1590 pg ·m-3 and 1960 pg ·m-3 in summer, respectively. However, a significant difference was observed in the distribution of 11 PBDE congeners, except BDE-209, during winter and summer seasons. The migration trend analysis showed the differences between the soil and air of FJ and BH. The main migration trend of 3-5-BDEs was the volatilization from soil to atmosphere, and the increase in temperature promoted the volatilization of these PBDEs from soil to atmosphere in FJ. This indicated that the PBDEs in soil had become a major source of pollution emission and suggested that soil remediation should be carried out at the e-waste dismantling site and parts of farmland in FJ. Contrary to FJ, atmospheric deposition was the major migration trend of PBDEs and the soil was the main sink of PBDEs in BH. This indicated that e-waste dismantling site in BH could be a new source of PBDEs emission in this area.

New Mixed Bromine/Chlorine Transformation Products of Tetrabromobisphenol A: Synthesis and Identification in Dust Samples from an E-Waste Dismantling Site.

The large-scale production and usage of tetrabromobisphenol A (TBBPA) and its analogues have caused widespread contamination, raising concern about their potential endocrine disruption effects on both humans and ecosystems. In the present study, debromination and unknown mixed bromine/chlorine transformation products of TBBPA (X-BBPA) were screened in dust samples from an e-waste dismantling site. Five monochloro products (2-chloro-2',6,6'-TriBBPA, 2-chloro-2',6-DiBBPA, 2-chloro-2',6'-DiBBPA, 2-chloro-2'-MoBBPA, and 2-chloro-6-MoBBPA) and two dichloro products (2,2'-dichloro-6,6'-DiBBPA and 2,2'-dichloro-6-MoBBPA) were successfully synthesized and structurally identified. TBBPA and its transformation products were detected by comparison of their mass spectra and retention times with those of synthetic standards. The mean concentration of X-BBPA was 1.63 × 104 ng/g in e-waste dismantling workshop dust samples based on dry weight, which was at a similar level to TBBPA. However, it was 1 order of magnitude lower than the concentrations of the debromination congeners. Thus, both debromination and chlorine-bromine exchange may be important reactions during the thermal processing of e-waste. The results on mixed chlorinated/brominated TBBPA transformation products provided new insights into TBBPA transformation. The elevated levels of the transformation products of TBBPA suggested that these products should be targeted to avoid underestimation of possible health risks.

Halogenated and organophosphorous flame retardants in surface soils from an e-waste dismantling park and its surrounding area: Distributions, sources, and human health risks

Electronic waste (e-waste) dismantling is an important source of flame retardant emissions, and may have potentially adverse effects on surrounding area. This study investigated their influence on the surrounding area and the human health risks after an industrial park was built in 2015 and environmentally friendly technologies were introduced at an e-waste dismantling site in South China. The concentrations of flame retardants, including polybrominated diphenyl ethers (PBDEs), polybromobenzenes (PBBzs), Dechlorane plus (DP), and organophosphate esters (OPEs), in the soils were measured. The results showed that soil contamination was greater in the industrial park than in the surrounding area. The PBDE concentrations were the highest with BDE209, a daca-BDE, being the dominant congener, followed by OPEs, where triphenyl phosphate levels were the highest. Furthermore, triphenyl phosphate can be used as an indicator of flame retardant emissions during e-waste dismantling in this region. The fanti value of DP was stable at around 0.75. The principal component analysis showed that direct emission was the major source of pollutants in the industrial park. The direct emission proportion decreased in the surrounding area, but migration and transformation increased. None of the chemicals posed a non-carcinogenic risks to children and adults via oral uptake or dermal contact when the absorption factors of the chemicals were included in the estimation. However, the total hazard quotients for children were close to a unit in the industrial park, of which, the PBDE and OPE proportions accounted for 84.2% and 15.8% of the total, respectively. However, the PBBz and DP percentages were negligible. Therefore, PBDEs and OPEs should be given more attention in the future.

Concentrations of bisphenol A and its alternatives in paired maternal–fetal urine, serum and amniotic fluid from an e-waste dismantling area in China

Bisphenol A (BPA) and its alternatives are suspected endocrine disruptors. However, prenatal exposure and transplacental transfer of bisphenols (BPs is still limited. Therefore, BPA and its six alternatives in maternal serum (MS), maternal urine (MU), cord serum (CS), and amniotic fluid (AF) samples collected from 106 maternal-fetal pairs in an e-waste dismantling site in Southern China were determined. Bisphenol AF (BPAF) and bisphenol S (BPS) were the dominant BPA alternatives observed in MS and CS, and the geometric mean (GM) concentration of BPAF (0.013 ng/mL in MS, 0.097 ng/mL in CS) and BPS (0.01 ng/mL in MS, 0.03 ng/mL in CS) in MS and CS was lower than that of BPA (0.5 ng/mL in MS, 1.2 ng/mL in CS). The ratios of BPA concentrations between MU and MS (MU:MS ratio) were over three times higher than those of AF and CS (AF:CS ratio), thereby suggesting low biotransformation/metabolism of BPA in fetuses. The placental transfer rates of BPs (i.e., CS:MS ratio) were compound-specific (BPAF 3.26, BPA 1.94, BPS 1.11). Results suggest that BPA and its alternatives can pass through the placental barrier. The placental transfer rates of BPs are positively related to molecular weight or log Kow values. This finding indicates that an active transport is responsible for the placental transfer of BPs.

Associations between metal exposure and global DNA methylation in potentially affected people in E-Waste recycling sites in Taizhou City, China

Electronic waste (e-waste) has been an emerging environmental health issue, and it has already provoked all aspects of attention. Taizhou is one of the three largest e-waste recycling locations in China. Atpresent, to prevent the environmental problems stem from e-waste dismantling, the local government has shut down all the industries in 2015. In this study, we collected blood samples of residents living near e-waste dismantling factories, and in matched reference areas in Taizhou, in December 2017, after the factories have been shut down for two years. Twenty-five metals were quantified in all blood samples. Among them, the concentrations of As, Ni, Ag, La, and Ce were statistically significant higher in individuals in e-waste recycling locations than those in reference location. Global DNA methylation was measured in blood as a marker of human health. Pearson correlation and multiple linear regression analysis between the changed metals and global DNA methylation in blood were performed. The result showed that only blood Ce was negatively correlated with global DNA methylation level significantly in pre-workers exposed e-waste workers (r = −0.51, p = 0.01). Our findings indicated that high concentrations of exposure to Ce in e-waste dismantling site could have sustained effects on the DNA methylation in blood although the e-waste industry had been closed for 2 years.

A convenient chemiluminescence detection for bisphenol A in E-waste dismantling site based on surface charge change of cationic gold nanoparticles

The crude disassembling for electronic waste (E-waste) has resulted in serious pollution of the environment in dismantling site. Convenient detection of single contaminant in dismantling site is very important to evaluating environmental pollution caused by single component during dismantling process and environment supervision. Herein, a novel chemiluminescence (CL) assay was constructed to detect ubiquitous pollutant bisphenol A (BPA) in dismantling site of E-waste based on surface charge change of cationic gold nanoparticles arising from the interaction of BPA and aptamer. The detection limit for BPA is 6.2 × 10−2 ng/mL, which is far lower than the requirements of Chinese Health Standards (0.05 mg/kg). The sensitivity can be attributed to the strong affinity between anti-BPA aptamer and BPA, and the direct and sensitive signal response of nanoparticles' microstructure for CL reaction. The high specificity of affinity between anti-BPA aptamer and BPA led to high selectivity of BPA detection, thus resisting the complexity of real environment. So, this analysis was successfully applied for the detection of BPA in the surface soil of E-waste dismantling site.

Associations between polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress in people living near e-waste recycling facilities in China

Emission of polycyclic aromatic hydrocarbons (PAHs) from e-waste recycling activities in China is known. However, little is known on the association between PAH exposure and oxidative damage to DNA and lipid content in people living near e-waste dismantling sites. In this study, ten hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and two biomarkers [8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA)] of oxidative stress were investigated in urine samples collected from people living in and around e-waste dismantling facilities, and in reference population from rural and urban areas in China. The urinary levels of ∑10OH-PAHs determined in e-waste recycling area (GM: 25.4μg/g Cre) were significantly higher (p<0.05) than those found in both rural (11.7μg/g Cre) and urban (10.9μg/g Cre) reference areas. The occupationally exposed e-waste workers (36.6μg/g Cre) showed significantly higher (p<0.01) urinary Σ10OH-PAHs concentrations than non-occupationally exposed people (23.2μg/g Cre) living in the e-waste recycling site. The differences in urinary Σ10OH-PAHs levels between smokers (23.4μg/g Cre) and non-smokers (24.7μg/g Cre) were not significant (p>0.05) in e-waste dismantling sites, while these differences were significant (p<0.05) in rural and urban reference areas; this indicated that smoking is not associated with elevated levels of PAH exposure in e-waste dismantling site. Furthermore, we found that urinary concentrations of Σ10OH-PAHs and individual OH-PAHs were significantly associated with elevated 8-OHdG, in samples collected from e-waste dismantling site; the levels of urinary 1-hydroxypyrene (1-PYR) (r=0.284, p<0.01) was significantly positively associated with MDA. Our results indicate that the exposure to PAHs at the e-waste dismantling site may have an effect on oxidative damage to DNA among selected participants, but this needs to be validated in large studies.

Concentration profiles, source apportionment and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in dumpsite soils from Agbogbloshie e-waste dismantling site, Accra, Ghana.

The concentrations of eighteen (18) polycyclic aromatic hydrocarbons (PAHs), including the 16 USEPA's priority PAHs as well as two alkyl-substituted naphthalenes were determined in dumpsite soils collected from different sampling sites within the Agbogbloshie e-waste dismantling site in Accra, Ghana. Following their isolation with ultrasonic-assisted extraction technique, the concentrations of the PAHs were determined by gas chromatography mass spectrometry (GC-MS). Loss-on-ignition (LOI) method was employed for the determination of total organic carbon (TOC) of the soil samples. The mean Σ18PAHs obtained were 3006, 5627, 3046, 5555, and 7199ngg(-1) dry weight (dw) for sampling sites A (mosque), B (dismantling site), C (residential house/police station), D (personal computer repairers' shop) and E (e-waste open burning area), respectively. In all cases, the prevalence of phenanthrene, fluoranthene and pyrene was generally observed across the sampling sites. In this study, PAHs with two to three rings and four to six rings exhibited strong positive correlations, whereas BbF and BkF showed weak positive and negative correlations with other PAHs investigated. With the exception of BbF and BkF, all the PAHs had moderate to strong positive correlations with the TOC. Benzo[a]pyrene equivalent (BaPeq) concentration is a useful indicator of the carcinogenic potency of environmental matrices and these ranged between 111 and 454ngg(-1), which are generally below the 'safe' level of 600ngg(-1) established for the protection of the environment and human health. Interestingly, the seven carcinogenic PAHs were the major contributors to the BaPeq concentrations accounting between 97.7 and 98.3 %. Despite the minimal risk to cancer via exposure to the investigated dumpsite soil as indicated in the present study, the prolonged exposure to these pollutants via various exposure pathways may result in increased risk to cancer over time. The application of several methodological approaches for PAH source apportionment, including the use of molecular diagnostic ratios, mostly implicated pyrogenic processes as the main sources of PAHs into the investigated dumpsite soils. Furthermore, their compositional profiles across the sampling sites also suggest similar sources of PAHs into the dumpsite soil.

Ecological Risk Assessment of EDTA-Assisted Phytoremediation of Cd Under Different Cultivation Systems.

A long-term field experiment was designed to assess remediation efficiency and ecological risk of phytoremediation of Cd under different cultivation systems with or without ethylene diamine tetraacetic acid (EDTA). EDTA can significantly improve the phytoremediation effectiveness of a historically polluted e-waste dismantling site through enhancing Cd uptake by plants in all cultivation systems along with higher ecological risks to different receptors especially in the presence of Cicer arietinum (chickpea). Moisture content at each layer of soil profile under Eucalyptus globules L. cultivated sites was consistently lower than under chickpea monoculture as a result of E. globules' high water use efficiency. Besides low soil moisture, E. globules can intercept more Cd-rich leachate than chickpea regardless of the presence of EDTA. E. globules could be used for Cd phytoremediation as they can take full advantage of EDTA and decrease ecological risk caused by the chelator.

Distribution and temporal variation of PCBs and PAHs in soils and sediments from an e-waste dismantling site in China

Temporal and geographical changes in the concentrations of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in soils and sediments around a typical e-waste dismantling area in China were systematically investigated. Dated soils and sediments from contaminated sites in the e-waste dismantling area were analyzed for PCBs congeners (1983–2012) and total PAHs (2004–2012). The results showed that the total concentration of PCBs ranged from 20.22 to 491.92 μg/kg dry weight (dw); the total concentration of PAHs ranged from 77.4 to 20,167.7 μg/kg dw; the sum of 6-dioxin-like (CB-28, 52, 101, 118, 138 and 180) and ∑PCBs in all the soils increased gradually from the early stage of pollution to the peak of pollution (317.85 and 927.30 μg/kg dw, respectively), but decreased after the control period of pollution (166.3 and 458 μg/kg dw, respectively). This work can provide information on pollution sources and evidence for short-range transport of POPs in e-waste dismantling areas, and useful data for e-waste recycling in China and other countries in the world.

Exposure to typical persistent organic pollutants from an electronic waste recycling site in Northern China

Human exposure to pollutants from e-waste is an important scientific issue for their health effects. In this study, organohalogen pollutants in human serum sample from an e-waste dismantling site (n=35) and a control site (n=21), both located in Tianjin, Northern China, were analyzed using GC–ECNI–MS. Geometric mean concentrations of tetra- through hexa-BDEs, hepta- through nona-BDEs, PCBs, PBB-153, and DP in the exposure group were 2.77, 12.2, 44.1, 0.52, and 7.64ngg−1 lipid, respectively, which ranged from 1.5 to 7.4-fold higher than those in the control group through multivariate regression analysis, indicating that working and/or living in the e-waste site was associated with elevated body concentrations of these pollutants. Pollutants with low vapor pressures (i.e., hepta- through nona-BDEs and DP) were at significantly higher levels for e-waste dismantling workers than for local residents living around the e-waste site, suggesting higher exposure to these pollutants might exist for the occupational workers.

Polycyclic aromatic hydrocarbons (PAHs) in soils and vegetation near an e-waste recycling site in South China: Concentration, distribution, source, and risk assessment

This study determined the concentrations of PAHs generated from e-waste recycling activities and their potential impacts on soil, vegetation, and human health. The total PAH concentrations in soils and plants ranged from 127 to 10,600 and 199 to 2420ng/g, respectively. Samples from an e-waste burning site had higher PAH concentrations than samples from adjacent locations. The PAHs in plants varied with plant species and tissue, and Lactuca sativa L. contained the highest PAHs of all the vegetable species. Various land use types showed different PAH concentrations in soils, with vegetable fields showing higher concentrations than paddy fields. Low molecular weight PAHs, such as phenanthrene, were the predominant congeners in soils, whereas high molecular weight PAHs, such as fluoranthene, pyrene, and benzo[a]anthracene, were enriched in plants relative to soils. Dissimilar PAH profiles in soil and the corresponding vegetation indicated that the uptake of PAHs by plants was selective. A source analysis showed that the contamination by PAHs originated primarily from the open burning of e-waste. The total daily intakes of PAHs and carcinogenic PAHs through vegetables at the e-waste dismantling site were estimated to be 279 and 108ng/kg/d, respectively, indicating that the consumption of vegetables grown near e-waste recycling sites is risky and should be completely avoided.

Characterization of PBDEs in soils and vegetations near an e-waste recycling site in South China

The concentration and composition of PBDEs in the soils and plants near a typical e-waste recycling site in South China were investigated. The total concentration of PBDEs (ΣPBDEs) in soil ranged from 4.8 to 533 ng/g dry wt. The ΣPBDEs in vegetation were from 2.1 to 217 ng/g dry wt. For the vegetable, the highest concentration of 19.9 ng/g dry wt. was observed in the shoot of Brassica alboglabra L. BDE 209 was the predominant congener in all samples. In comaprison with other e-waste contaminated sites in China, lower concentrations of PBDEs and higher concentrations of PCBs were observed in both soils and plants suggesting different e-waste types involved in the present study. The PBDEs contaminated vegetables around the e-waste dismantling site may pose a potential health risk to the local inhabitants.

Association of Changes of Thyroid Hormone Levels With Brominated Flame Retarded Exposure Around E-waste Dismantling Site

PP-29-109 Background/Aims: Brominated flame retarded (BFR) released from e-waste activity might affect the health of local people. Assessing the effect of e-waste exposure via recycling, and dismantling and changes of thyroid hormone levels is an area of ongoing research. Methods: The processing of e-waste recycling was investigated. A total of 236 occupational exposure people and 89 nonoccupational exposure people from e-waste recycling sites were surveyed, and their thyroid hormone levels (T3 and T4), free thyroid hormones (fT3 and fT4), and thyroid stimulating hormone were assayed. The level of polybrominated diphenyl ethers congeners and Polybrominated biphenyl congeners in serum was determined here. Linear regression model was taken to analyze the relations between thyroid hormone levels and BFRs concentrations. Results: Lower level of T3 in exposure groups were observed (P < 0.01). BDE205 with T4 positively varied were confirmed by linear regression model (unstandardized regression coefficient, beta = 0.25, ρ = 0.001) and a weaker positively trend in BDE126 and T4 was found. Conclusion: BFRs exposure may contribute to the changes of thyroid hormone levels.

Spatial distribution of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs) in an e-waste dismantling region in Southeast China: Use of apple snail ( Ampullariidae) as a bioindicator

Fengjiang is a large e-waste dismantling site located in southeast China. In this paper, apple snail and soil samples were collected from this e-waste dismantling site and 25 vicinal towns to investigate the contamination status, spatial distributions and congener patterns of polychlorinated biphenyls (PCBs) and polybrominated biphenyl ethers (PBDEs). Total PCB concentrations in apple snails (3.78–1812 ng g −1 dry weight (dw)) were significant higher than that in soil samples (0.48–90.1 ng g −1 dw). PBDE (excluding BDE 209) concentrations in apple snail and soil samples ranged from 0.09 to 27.7 ng g −1 dw and 0.06 to 31.2 ng g −1 dw, respectively. Concentrations of PCBs and PBDEs in snails and soils correlated negatively with the distance from Fengjiang. Both the concentrations and profiles of the pollutants were significantly correlated ( p < 0.05) between the snail and soil samples, indicating the suitability of apple snail as a reliable bioindicator for PCBs and PBDEs contamination in this region. Relatively high concentrations of PCBs and PBDEs at locations far from e-waste dismantling sites implied that these pollutants have been transported to surrounding regions.

Study on the changes of urinary 8-hydroxydeoxyguanosine levels and burden of heavy metal around e-waste dismantling site

To examine the relations between the burden of blood copper (B-Cu), blood ferrous (B-Fe), and the oxidative stress in people around electronic waste (e-waste) recycling sites, this study measured and analyzed the level of urinary 8-Hydroxy-2′-deoxyguanosine (8-OHDG) of these people. Exposed groups, consisted of female groups (directly exposed group n = 100, indirectly exposed group n = 54) and male groups (directly exposed group n = 98, indirectly exposed group n = 34), were chosen from e-waste recycling sites. Control group (female n = 59, male = 32) was selected from a green plantation. Questionnaire surveys for risk factors were also performed. Results indicated the male directly exposed group (lg8-OHDG nmol/mol creatinine, mean ± SD, 3.55 ± 0.49) showed a lower 8-OHDG level than the male control group (lg8-OHDG nmol/mol creatinine, mean ± SD, 3.89 ± 0.29) ( p < 0.01), Meanwhile, an elevated B-Fe in male directly exposed group (lgB-Fe ug/L 3.11 ± 0.25) were observed compared with the male control group (lgB-Fe ug/L 2.83 ± 0.22) ( p < 0.01). The levels of urinary 8-OHDG were negatively associated with blood ferrous, as confirmed by linear regression model (unstandardized regression coefficient, beta = −0.215, p < 0.05). The present study suggests that the exposure to e-waste might cause the elevation of B-Fe and result in the changes of urinary 8-OHDG levels.

Polymorphisms of GSTT1 and GSTM1 and increased micronucleus frequencies in peripheral blood lymphocytes in residents at an e-waste dismantling site in China

In the present study, we investigated whether genetic polymorphisms of metabolic enzymes in an exposed population were associated with genotoxic effects of the pollutants from e-waste in 58 subjects (the exposed) resided in a typical e-waste recycling site and 80 subjects (the controls) from a village away from the recycling site. Effects of genetic polymorphisms of glutathione S-transferases (GSTs) (GSTT1 and GSTM1) on the frequency of micronucleated binucleated cells (MNed BNC) in peripheral blood lymphocytes were evaluated. GSTM1 and GSTT1 were typed using PCR-restriction fragment length polymorphism methods. Cytogenetic alterations were evaluated using the cytokinesis-block micronucleus assay. The MNed BNC frequency was significantly higher in the exposed group (median: 4.0‰, IQR: 2.0–7.0‰) than in the control group (median: 1.0‰, IQR: 0.0–2.0‰, P < 0.01 for both comparisons); sera GST activities were also higher in the exposed subjects with either non-null GSTT1 (mean ± SD: 20.27 ± 6.43) or non-null GSTM1 (mean ± SD: 19.71 ± 4.89) than in the controls (mean ± SD: 18.79 ± 4.91 and 19.34 ± 6.42, respectively, P < 0.05 for both). Although the increased MNed BNC frequencies among the exposed group may be associated with the co-exposure of various chemical pollutants in the environment, there was no statistical evidence of an association between GSTs genotypes and frequencies of micronuclei in the study population. Because this study size was small, the mechanism of genotoxic effects caused by exposure to e-waste needs to be further validated in larger studies.

Bioaccumulative characteristics of hexabromocyclododecanes in freshwater species from an electronic waste recycling area in China

Hexabromocyclododecanes (HBCDs) are now emerging ubiquitous contaminants due to their wide usage, persistence and toxicities. To investigate the bioaccumulative characteristics of HBCDs, sediments, Winkle ( Littorina littorea), crucian carp ( Carassius carassius) and loach ( Misgurnus anguillicaudatus) were collected from two streams near an E-waste dismantling site in China, and HBCD exposure test was then conducted on Chinese rare minnow. The concentration of HBCDs was 14 ng g −1 dry weight in sediments, 186, 377 and 1791 ng g −1 lipid weight in winkle, crucian carp and loach, respectively. γ-HBCD was found to be the dominant diastereoisomer in the sediments (63% of total HBCDs). However, α-HBCD was selectively accumulated in the biotic samples and contributed to 77%, 63% and 63% of total HBCDs in winkle, crucian carp and loach, respectively. Moreover, an enrichment of (−)-enantiomers of α- and γ-HBCD were found in the winkle. The reverse results were observed in the crucian carp and loach. Similar observations of diastereoisomeric and enantiomeric composition were obtained in Chinese rare minnow with those found in the crucian carp and loach. These results indicate that the freshwater species from the streams are contaminated by HBCDs. α-HBCD can be selectively accumulated in organisms and the accumulative characteristics are enantioselective among species.

Analyses of levels of thyroid hormones and its receptor expression in puerperants and newborns from an e-waste dismantling site

In this study, the serum levels, including thyroid hormones free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone(TSH)among the subjects from the exposed group (n = 48) and the control group (n = 45) were detected by immuno radiometric assay (IRMA). The expression levels of TRα1, TRβ1, TSHR mRNA in placentas and umbilical cords were detected by fluorescent quantitative real-time PCR (FQ-PCR). The correlations between the thyroid hormone levels in maternal serum and umbilical serum, and between the expression levels of its receptors mRNA in placentas and umbilical cords were determined. We found that the FT4 levels of both maternal serum and umbilical cord serum in the exposed group were lower than those in the control (P < 0.05). However, the increased TSH levels in the exposed group had statistically significance compared to those in the control group (P < 0.05). The TRα1 and TRβ1 mRNA levels both in placentas and umbilical cords in the exposed group were lower than those in the control group (P < 0.05 and 0.01). However, the TSHR mRNA levels in the exposed group were significantly different compared to those in the control group (P < 0.01). The serum FT4 and TSH levels of parturient women were positively correlated with those of the newborns in both groups (P < 0.05 and 0.01). The mRNA levels of TRα1, TRβ1 and TSHR in the placentas were positively correlated with those in umbilical cords in both groups (P < 0.01). The findings suggest that some environmental pollutants existing in the electronic waste (e-waste) dismantling region may affect the health of local parturient women and newborns, representing changes both in serum levels of thyroid hormones and in mRNA expression of its receptors.