Jianjie Fu

High levels of heavy metals in rice (Oryza sativa L.) from a typical E-waste recycling area in southeast China and its potential risk to human health

Very few studies have investigated the heavy metal contents in rice samples from a typical E-waste recycling area. In this study, 10 heavy metals (As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni and Pb) in 13 polished rice and relevant hull samples, six relevant paddy soil samples were investigated. The geometric mean concentrations of Cd, Cu and Hg in soil samples were 1.19, 9.98 and 0.32 microg g(-1), respectively, which were 4.0, 2.0 and 1.1-folds of the maximum allowable concentration (MAC) (0.30, 50.00, 0.30 microg g(-1), respectively) for Chinese agricultural soils. The analyzed metal concentrations were significantly different between rice and relevant hull except for As, Cd and Hg (p<0.05). All metal concentrations, except for Co, in rice hull were higher than those in polished rice. The geometric mean of Pb in polished rice reached 0.69 microg g(-1), which was 3.5-folds higher than the MAC (0.20 microg g(-1)) by the safety criteria for milled rice. Cd contents in 31% of the rice samples exceeded the national MAC (0.20 microg g(-1)), and the arithmetic mean also slightly exceeded national MAC. In addition, Cd and Pb contents in local rice were much higher than commercial rice samples examined in this work and previous studies. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb daily intake through rice consumption in this area was 3.7 microg day(-1)kg(-1) body weight (bw), which already exceeded the FAO tolerable daily intake, and the Cd daily intake (0.7 microg day(-1)kg(-1) bw) through rice had already taken up 70% of the total tolerable daily intake (1 microg day(-1)kg(-1) bw). The daily intake of Hg and As through rice was much lower than the tolerable daily intakes, but bioaccumulation of Hg through the food chain and intake of As from other food stuff should also be of concern.

Effects of waterborne nano-iron on medaka (Oryzias latipes) : antioxidant enzymatic activity, lipid peroxidation and histopathology

Toxicity tests were performed to investigate possible harmful effects on medaka exposed to nano-iron. Dose-dependent decreases of superoxide dismutase (SOD) and increases of malondialdehyde (MDA) were induced in the medaka embryo, suggesting that oxidative damage was induced by nano-iron. For adult medaka, the disturbance of antioxidative balance was observed during the early exposure period based on the monitoring of the hepatic and cerebral SOD and reduced glutathione (GSH). No terminal oxidative damage occurred during the whole exposure period, probably due to the high self-recovering capability of the adult fish. Some histopathological and morphological alterations (cell swelling, hyperplasia, and granulomas, etc.) were observed in gill and intestine tissues, which confirmed that deleterious effects occurred as a result of direct contact with nano-iron. It is suggested that further evaluation should be made concerning the risk assessment of waterborne nano-iron on aquatic life.

Use of scalp hair as indicator of human exposure to heavy metals in an electronic waste recycling area

Scalp hair samples were collected at an electronic waste (e-waste) recycling area and analyzed for trace elements and heavy metals. Elevated levels were found for Cu and Pb with geometric means (GMs) at 39.8 and 49.5 microg/g, and the levels of all elements were found in the rank order Pb > Cu >> Mn > Ba > Cr > Ni > Cd > As > V. Besides Cu and Pb, Cd (GM: 0.518 microg/g) was also found to be significantly higher compared to that in hair samples from control areas. Differences with age, gender, residence status and villages could be distinguished for most of the elements. The high levels of Cd, Cu and Pb were likely found to be originated from e-waste related activities, and specific sources were discussed. This study shows that human scalp hair could be a useful biomarker to assess the extent of heavy metal exposure to workers and residents in areas with intensive e-waste recycling activities.

Distribution of Perfluorooctane Sulfonate and Other Perfluorochemicals in the Ambient Environment around a Manufacturing Facility in China

Perfluorinated compounds (PFCs) can be released to the surrounding environment during manufacturing and usage of PFC containing products, which are considered as main direct sources of PFCs in the environment. This study evaluates the release of perfluorooctane sulfonate (PFOS) and other PFCs to the ambient environment around a manufacturing plant. Among the nine PFCs analyzed, only PFOS, perfluorooctanoic acid (PFOA), and perfluorohexane sulfonate (PFHxS) were found in dust, water, soil, and chicken eggs. Very high concentrations of PFOS and PFOA were found in dust from the production storage, raw material stock room, and sulfonation workshop in the manufacturing facility, with the highest value at 4962 μg/g (dry weight) for PFOS and 160 μg/g for PFOA. A decreasing trend of the three PFCs concentrations in soils, water, and chicken eggs with increasing distance from the plant was found, indicating the production site to be the primary source of PFCs in this region. Risk quotients (RQs) assessment for surface water >500 m away from the plant were less than unity. Risk assessment of PFOS using predicted no-effect concentration (PNEC, 3.23 ng/g on a logarithmic scale) indicated no immediate ecological risk of a reduction in offspring survival. PFOS concentrations in most egg samples did not exceed the benchmark concentration derived in setting a reference dose for noncancer health effects (0.025 μg/(kgxd)).

Influence of E-Waste Dismantling and Its Regulations: Temporal Trend, Spatial Distribution of Heavy Metals in Rice Grains, and Its Potential Health Risk

Enhanced regulations, centralized dismantling processes, and sophisticated recycling technologies have been implemented in some e-waste dismantling areas in China with regard to environmental and economic aspects since 2005. In this study, rice grain samples were collected from 2006 to 2010 in an e-waste dismantling area to investigate the temporal trends and spatial distribution of As, Cd, Cu, and Pb. Geometric means of As, Cd, Cu, and Pb in rice samples from the e-waste dismantling area were 111, 217, 4676, and 237 ng g(-1), respectively. Levels of Pb showed a significant decreasing trend during the sampling period, whereas the other three elements remained relatively constant or even increased. Concentrations of Cd, Cu, and Pb in the e-waste dismantling area were significantly higher than those in the non-e-waste dismantling area (p < 0.05), which showed a close connection between e-waste dismantling activities and elevated Pb, Cu, and Cd contents. Risk assessment for human via rice consumption indicated that over 60% of the hazard quotient of Cd exceeded 1 in the e-waste dismantling area. Our study implied that stricter implementation of regulatory measures might lead to positive effects in controlling the release of some heavy metals to the environment. However, environmental behaviors differed with geochemical characteristics of individual elements. Further remediation actions to reduce heavy metal pollution to the surrounding environment might still be needed.

Short Chain Chlorinated Paraffins in Mollusks from Coastal Waters in the Chinese Bohai Sea

As an extremely complex group of persistent organic pollutants (POPs) candidates in the Stockholm Convention, short chain chlorinated paraffins (SCCPs) have been of extensive concern in recent years. In this study, nine bivalve and two gastropod species were collected in 2009 to evaluate the spatial distributions and potential factors influencing the bioaccumulation of SCCPs in mollusks in the Chinese Bohai Sea. The concentrations of ∑ SCCPs in the mollusks were in the range 64.9-5510 ng/g (dry weight) with an average chlorine content of 61.1%. C(10) and C(11) were the predominant homologue groups of SCCPs, which accounted for about 29.7% and 34.9% of ∑ SCCPs, respectively. Six and seven chlorinated substituents were the main congener groups. Mya arenaria (Mya), Mactra veneriformis (Mac), and Crassostrea talienwhanensis (Oyster, Ost) had higher average concentrations of SCCPs than other species, implying that these bivalves could be used as sentinels to indicate SCCPs contamination in this coastal region. A significant positive linear relationship was found between SCCP concentrations and lipid content of the mollusks, whereas the lipid-normalized SCCP concentrations were negatively linear-related to the trophic levels (TL), which implied that SCCPs did not show biomagnification in mollusks in this region.

Identification of Tetrabromobisphenol A Diallyl Ether as an Emerging Neurotoxicant in Environmental Samples by Bioassay-Directed Fractionation and HPLC-APCI-MS/MS

Brominated flame retardants (BFRs) have been widely used as additives in products to reduce their flammability. Recent findings suggested that some BFRs exhibit neurotoxicity and thus might pose a threat to human health. In this work, a neurotoxicity assay-directed analysis was developed, combining sample cleanup, fractionation, chemical identification, and bioassay. Viability of primary cultured cerebellar granule neurons (CGNs) was used to evaluate the neurotoxicity of extracts or separated fractions from environmental samples. Tetrabromobisphenol A diallyl ether (TBBPA DAE) was identified as the causative toxicant in sediment samples collected from a river near a brominated flame retardant (BFR) manufacturing plant in South China. Liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS/MS) was optimized to determine TBBPA DAE levels in the potent fractions and to confirm TBBPA DAE as the key neurotoxicant. On the basis of comparison with the structure of other TBBPA derivatives, the 1-propenyl group in TBBPA DAE appears to be the cause for the neurotoxic potency. The levels of TBBPA DAE in samples along the river were found at up to 49 ng/L for river water, 10,183 ng/g dry weight (dw) in surface sediments, and 42 ng/g dw in soils. According to the distribution of TBBPA DAE in the environmental samples, the manufacturing plant was identified as the release source of TBBPA DAE. To our knowledge, this study is the first to demonstrate potential neurotoxicity induced by TBBPA DAE in real environmental samples.

Tris(2,3-dibromopropyl) Isocyanurate, Hexabromocyclododecanes, and Polybrominated Diphenyl Ethers in Mollusks from Chinese Bohai Sea

A novel brominated flame retardant (BFR), tris(2,3-dibromopropyl) isocyanurate (TBC), as well as hexabromocyclododecanes (HBCDs) and polybrominated diphenyl ethers (PBDEs), were analyzed in 11 species of mollusks collected from nine coastal cities around the Chinese Bohai Sea in 2009 and 2010. The detection frequencies were 100%, 99%, and 77% for PBDEs, HBCDs, and TBC, respectively. Concentrations of ∑HBCDs ranged from below detection limit (nd) to 28.8 ng g(-1) on a dry weight (dw) basis, followed by ∑(12)PBDE (0.01-20.4 ng g(-1) dw) and TBC (nd-12.1 ng g(-1) dw). Statistically significant linear correlations were found among the three BFRs. Positive correlations were found between BFRs concentrations and lipid content in mollusks. The concentrations tend to decrease with increasing trophic levels of the mollusks, implying trophic dilution rather than biomagnifications of the BFRs in the aquatic food chains of the sampling area. Among the 11 mollusks species, Mytilus edulis showed higher bioaccumulation capability than others and was therefore considered to be an appropriate bioindicator of contamination by the BFRs in the Chinese Bohai Sea, in agreement with its previous selection for the biomonitoring of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). A dramatic decrease in PBDE concentrations in mollusks of the area was found for the time period from 2003 to 2010, with a half-life of only 2.3 ± 1.7 years, reflecting a rapid response of mollusks to the change in pollution of the marine environment.

Bioaccumulation of PCDD/Fs, PCBs and PBDEs by earthworms in field soils of an E-waste dismantling area in China.

A total of 60 paired samples of earthworm, corresponding soil and wormcast were collected to investigate the bioaccumulation tendency of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in earthworms from a typical E-waste dismantling area in east China. Significant correlations were observed for the total concentrations among different matrix types except for PCDD/Fs in soil and earthworm. The bioaccumulation tendency showed some differences among the contaminants. Calculated biota-soil accumulation factors (BSAFs) indicated that PCBs and PBDEs had higher bioaccumulation potential compared to PCDD/Fs, which was somewhat different from laboratory studies. The plot of mean BSAFs versus log Kow values for PCBs and PBDEs was well fitted by a second-order polynomial with the maximum BSAF at approximately log Kow of 6.5. While for PCDD/Fs, only a slightly decreasing trend was observed with increasing log Kow. Composition analysis indicated that tetra-, penta- and hexa-halogenated homologs had higher bioaccumulation levels, indicating that medium-halogenated congeners with log Kow around 6.5 are more easily accumulated by earthworms. Furthermore, the ratios of BDE-47/-99 and BDE-99/-100 showed some discrepancies with the technical products and other biotic species, suggesting different bioaccumulation potential of PBDEs in earthworm.

Temporal trends (2005-2009) of PCDD/Fs, PCBs, PBDEs in rice hulls from an e-waste dismantling area after stricter environmental regulations

Primitive e-waste dismantling activities have been of increasing concern due to serious environmental and human health problems, and therefore authorities in China have strengthened the regulations on illegal e-waste recycling activities. In this work, we used rice hull as a passive sampler and investigated temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) in areas near e-waste recycling sites after the stricter regulations. Furthermore, the distribution patterns and composition profiles of these contaminants were also discussed. The average concentrations of the three groups of persistent organic pollutants (POPs) in rice hulls have markedly decreased during the period of 2005-2009. Specifically, from 12.9 (average value in 2005) to 0.37 pg WHO-TEQ/g (dry weight, dw) (in 2009) for PCDD/Fs, 47.6 (2005) to 7.10 ng g(-1)dw (2009) for PCBs, and 2.51 (2005) to 0.89 ng g(-1), dw (2009) for PBDEs. The significant decrease of combustion markers 2,3,4,7,8-PeCDF, 1,2,3,6,7,8HxCDF and PCB126, and the PCDD/PCDF ratio from 1:9 (2005) to 7:3 (2009) is likely a result of stricter regulations on open combustion activities. This study suggests that stricter control measures, strengthened laws and regulations and more environmental friendly techniques could be effective measures in reducing the release and formation of related POPs in typical e-waste dismantling sites, and these measures could further improve the quality of the environment and health of the local inhabitants.