E-waste Recycling Area In China Research Articles

Dioxins in breast milk of Chinese mothers: A survey 40 years after the e-waste recycling activities

In the past two decades, numerous studies on dioxin concentrations in breast milk have been conducted in China. However, information concerning dioxin concentrations in breast milk from women living in e-waste recycling sites remains limited. Thus, this study aimed to evaluate health risk owing dioxin intake in e-waste recycling areas in China. In 2015, 42 mothers were recruited from an e-waste recycling site, and the same number of mothers were recruited from a reference site. We collected 10-mL breast milk samples from each participant. Breast milk concentrations of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) were significantly higher in the exposed group than in the reference group. The total toxic equivalents (TEQ) of PCDDs/DFs were 9.68 pg/g lipid in the exposed group, a value two times higher than those in the reference group (4.18 pg/g lipid). The estimated daily intake (EDI) of PCDD/DFs was calculated to assess the risk of dioxins through breastfeeding. The infant EDI level was two times higher in the exposed group (54.21 pg TEQ/kg body wt/day) than in the reference group (23.41 pg TEQ/kg body wt/day). Our findings suggest that mothers and their breastfeeding infants living in an e-waste recycling site were exposed to higher dioxin concentrations than those living in a reference site.

Methylsiloxanes and Their Brominated Products in One e-Waste Recycling Area in China: Emission, Environmental Distribution, and Elimination.

The present study investigated the sources and fates of methylsiloxanes and their brominated products in one e-waste recycling area of China. During thermal (30-1000 °C) recycling experiments for printed wiring boards (PWBs), besides volatile methylsiloxanes (D4, D5, and D6), their monobrominated products, that is, D3D(CH2Br), D4D(CH2Br), and D5D(CH2Br), were also found by quadrupole time-of-flight gas chromatography-mass spectrometry to have 2-3 orders of magnitude lower emissions (0.31-1.3 μg/g) than those (18.1-866 μg/g) of parent methylsiloxanes. Overall, the fastest emissions of methylsiloxanes and bromo-methylsiloxanes occurred at 300-400 and 400-500 °C, respectively, accounting for 35.3-51.0 and 39.4-82.1% of their total emission. In the e-waste recycling area, concentrations of D4-D6 were 1.1-75.0 μg/g dw [detection frequency (df) = 100%] in 31 dusts from PWB treatment workshops, while limits of detection (LOD) < 683 ng/g dw (df = 69-100%) in 48 surrounding soils were up to 3 orders of magnitudes higher than those in reference areas. Meanwhile, D3D(CH2Br)-D5D(CH2Br) were detected in both dusts (<LOD-1.2 μg/g dw, df = 48-52%) and soils (<LOD-70.3 ng/g dw, df = 23-77%) from the e-waste recycling area, but they were not present in reference samples. Simulating experiments showed that hydrolysis (9.07-378 d) and volatilization (8.55-1007 d) half-lives of monobrominated D4-D6 in soils were 1.6-5.0 times longer than those of their parent methylsiloxanes.

Impact of informal e-waste recycling on human health

Increasing e-waste has become a major problem for global environment and public health. In the process of dismantling and recycling of disordered electronic waste, heavy metals such as lead and brominated flame retardants and organic substances are released into environmental media such as air, soil, dust and water, which is harmful to the health of local residents. Taking an e-waste dismantling area in Guangdong Province as an example, this paper reviews exposure levels of heavy metals and organic matters in e-waste recycling areas in China, as well as the health effects of local residents. Previous studies have found that e-waste recycling activities led to serious environmental pollution and high exposure levels of heavy metals and organic matters in local residents, which has a certain impact on the physiological functions of various human systems. The establishment of a centralized dismantling zone can effectively reduce the load level of various pollutants.