Assessment of cadmium exposure for neonates in Guiyu, an electronic waste pollution site of China

摘要

Analytical Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou 515041, China;Analytical Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou 515041, China;Analytical Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou 515041, China;Analytical Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou 515041, China;Analytical Cytology Laboratory and the Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou 515041, China;Research Center for Reproductive Medicine, Department of Cell Biology and Genetics, Shantou University Medical College, 22 Xinling Rd., Shantou 515041, Guangdong, People's Republic of China;%This study aimed to determine the levels of placental cadmium (PCd) and cord blood cadmium (CBCd) and the resulting expression of placental metallothionein (MT) in neonates and to investigate cadmium (Cd) exposure levels in neonates and mothers who live in Guiyu, China, an electronic waste (e-waste) pollution site. Among the 423 mothers included in the study from 2004/2005 to 2007, 289 lived in Guiyu (exposed group) and 134 lived in Chaonan, located 10 km away from Guiyu (controls) and had never been exposed to e-waste pollution. CBCd and PCd levels were measured by atomic absorption spectrometry. Placental MT was examined by immunohistochemistry. Information on maternal and neonatal characteristics and exposure conditions was obtained from hospital records and by personal interviews. For the 3 years, the median CBCd was higher for Guiyu neonates than for controls (3.61 vs. 1.25 μg/L), with 25.61% of Guiyu subjects exhibiting a median CBCd that exceeded the safety limit defined by the World Health Organization (5 μg/L), as compared with 14.18% of control neonates (p < 0.01). In Guiyu, the mean PCd was higher than that for controls (0.17 ± 0.48 vs. 0.10 ± 0.11 ug/g, p < 0.01). The high levels of CBCd and PCd were significantly associated with parents' occupational and environmental exposure to e-waste recycling pollutants. Staining for MT was positive and dense for 67.00% (67/100) of Guiyu neonates as compared with 32.69% (17/52) of controls (p < 0.01). Exposure to e-waste recycling pollutants increased Cd exposure in neonates, which was accompanied by increased placental MT expression.