| Background and ObjectiveGuiyu, located in the southeast of China, was an e-waste recycling center for e-waste, wherenearly 60–80% of families have engaged in primitive e-waste processing and recycling activities.Guiyu has accommodated millions of tons of e-waste arriving from overseas and domestic,during the e-waste dismantling and recycling process, no protections for the health or theenvironment were taken, various hazardous heavy metals are released to the environment,threatening the health of local residents. Several studies have found high levels of toxic heavymetals in samples of dust, soil, river sediments, surface water and ground water in Guiyu.researches is needed to investigate the adverse health effects on local children. In this study, 118children with a average age of 4 years old were recruited from Guiyu, Blood lead levels (BLLs),blood cadmium levels (BCLs) and blood chromium levels were measured as biomarkers forexposure, urine 8-hydroxydeoxyguanosine (8-OHdG) levels and mRNA expression of the DNArepair gene Human oxoguanine glycosylase-1(hOGG1)in peripheral blood lymphocyte wereused as biomarkers for exposure to ROS, we investigate possible associations between bloodlead and cadmium levels with hOGG1 mRNA levels in blood and urinary 8-OhdG to assess theheavy metals-induced oxidative effect in children.Materials and MethodsWe recruited 118 children from Guiyu, aged from 3 to 7 years old. After informed consents wereobtained from their parents or guardians, blood and urine samples were collected from thechildren at village kindergarden by well-trained nurses, placed on ice, and then were transportedto the lab, store at -70°C until analysis. Physical indexes (height and weight, head and chestcircumferences) were also measured. To avoid contamination, all analytical plastic tubes andcontainers were purchased of low-metal grade and were further cleaned with diluted nitric acidbefore use. Questionnaires were administered to parents for information of diet, living condition,parental smoking, occupation, economic statue and medical information. This study wasapproved by the Human Ethics Committee of Shantou University Medical College.Results1. The blood level of Lead in 118 children range from 3.70μg/dL to 21.64μg/dL with a mean of8.24μg/dL and the blood level of Cdamium in 118 children range from 0.27μg/L to 6.86μg/Lwith a mean of 0.857μg/L. 2. According to the blood lead level, we divided the study group by quartile, hOGG1 expressionwas significantly correlated with the higher blood Lead level (>7.43μg/dL, median). Comparedwith the first quartile(> 5.90μg/dL), A significant increase of urinary 8-OHdG level wasobserved in the second (>5.90μg/dL but < 7.43μg/dL) and the forth quartile(9.43-21.64μg/dL).moreover, the urinary 8-OHdG level is correlative with the blood Lead level.3. No significant relationship between the levels of blood cadmium and 8-OHdG, hOGG1expression was found in the whole study group. However, when we divided the whole studygroup by sex, hOGG1 expression was significantly negatively correlated with the bloodCadmium level in the female children. And the trend was not observed in male children, ourresults also show that hOGG1 expression in female children with blood Cadmium level higherthan 0.72μg/L, was significantly elevated compared with children with a blood Cadmium levellower than 0.72μg/L.ConclusioConclusionThe BLL and BCL of children in Guiyu had somewhat declined. Reasons for the descendingtrend of BLL and BCL in children might be the government's regulation in e-waste processing,our work in improving the environmental and health awareness of local people, and most of all,many home work-shop had been closed due to the world economy recession in 2009 which hadaffect the guiyu e-waste process business greatly. hOGG1 expression was elevated in higherblood lead. Because hOGG1 is the main enzyme responsible for removing 8-oxyguanine fromDNA, this study thus supports previous reports that lead increases the level of oxidative damageto DNA. unregulated e-wastes disposal has affected the lead and cadmium levels of children inelectronic wastes recycling district. The environmental heavy metals pollution caused byrecycled electronic waste probably strongly affects the children health. |
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