Elevated Blood Lead Levels of Children in Guiyu, an Electronic Waste Recycling Town in China

Disposal of electronic waste, or e-waste, is an emerging global environmental issue, as these wastes have become the most rapidly growing segment of the municipal waste stream in the world [Dahl 2002; Halluite et al. 2005; Jang and Townsend 2003; Schmidt 2002; Silicon Valley Toxics Coalition (SVTC) 2001]. It is reported that approximately 500 million computers became obsolete between 1997 and 2007 in the United States (National Safety Council 1999). Up to 80% of e-waste from the United States has seeped into Asia and Africa (Johnson 2006; Puckett et al. 2002; Schmidt 2002, 2006; SVTC 2001). It is noteworthy that the United States is the only developed country today that has not ratified the United Nations Basel Convention, which bans the export of hazardous wastes to developing countries (United Nations Environment Programme 1992, 2006; USA Today 2002). Together with New Delhi in India, Guiyu in Shantou, Guangdong Province, China (Figure 1), is one of the popular destinations of e-waste (Brigden et al. 2005; Puckett et al. 2002). Within a total area of 52 km2 and local population of 132,000 (in 2003), Guiyu has accommodated millions of tons of e-waste from overseas and domestic a year. Nearly 60–80% of families in the town have engaged in e-waste recycling operations conducted by small scale family-run workshops, with approximately 100,000 migrant workers employed in processing e-waste. Because the implementation of a clean and safe high-tech recovery process was very expensive (Allsopp et al. 2006), the processes and techniques used during the recycling activities in Guiyu were very primitive. The result was that many tons of e-waste material and process residues were dumped in workshops, yards, roadsides, open fields, irrigation canals, riverbanks, ponds, and rivers. Hazardous chemicals can be released from e-wastes through disposal or recycling processes, threatening the health of local residents. Several studies have reported the soaring levels of toxic heavy metals and organic contaminants in samples of dust, soil, river sediment, surface water, and groundwater of Guiyu (Brigden et al. 2005; Puckett et al. 2002; Wang and Guo 2006; Wang et al. 2005; Wong et al. 2006; Yu et al. 2006). Previously, we have shown that the residents in Guiyu had high incidence of skin damage, headaches, vertigo, nausea, chronic gastritis, and gastric and duodenal ulcers, all of which may be caused by the primitive recycling processing of e-waste (Qiu et al. 2004). Figure 1 Map of Guiyu and Chendian, with latitude and longitude. Of many toxic heavy metals, lead is the most widely used in electronic devices for various purposes, resulting in a variety of health hazards due to environmental contamination (Jang and Townsend 2003; Musson et al. 2006; Vann et al. 2006). Lead enters biological systems via food, water, air, and soil. Children are particularly vulnerable to lead poisoning—more so than adults because they absorb more lead from their environments (Baghurst et al. 1992; Grigg 2004; Guilarte et al. 2003; Jain and Hu 2006; Needleman 2004; Safi et al. 2006; Wasserman et al. 1998). The U.S. Centers for Disease Control and Prevention (CDC) defined elevated blood lead levels (BLLs) as those ≥ 10 μg/dL in children ≤ 6 years of age (CDC 1991). Nevertheless, studies have increasingly shown that low blood lead concentrations, even < 10 μg/dL, were inversely associated with children’s IQ scores and academic skills (Canfield et al. 2003; Lanphear et al. 2000, 2005; Nevin 2000; Schnaas et al. 2006). Therefore, no safety margin at existing exposures has been identified (Chiodo et al. 2004; Koller et al. 2004). Considering the potential heavy metal contamination in the local living environment of Guiyu, we hypothesized that children living in Guiyu may have elevated BLLs and thus their physical and mental development may have been affected. In this study, we evaluated the mean BLLs in children 1–6 years of age living in Guiyu and compared them with those living in the neighboring town of Chendian, where no e-waste processing was taken.