Decreased titers of HBsAb linked to e-waste lead exposure in preschool children

Background: E-waste is becoming the most important waste in the world. Among various recovery techniques, informal processing of e-waste in developing countries has caused serious environment and health problems. Guiyu in southern China is one of the biggest destinations of e-waste in the world and has 30 years of manual recycling history. From nine years ago, we begun to describe Pb, Cd, Cr,Ni, PBDEs, PAHs, PCB PFOA in local neonates and children were significantly higher than those of control areas. Aims: In this study, we investigate how heavy metals, especially lead exposure in this e-waste areas impacts on the levels of antibodies against human hepatitis B surface antigen (HBsAbs) expression, as well as lymphocyte subsets in hepatitis B-immunized children. Methods: Children from e-waste recycling town, Guiyu and non-recycling control town were enrolled. HbsAb, lymphocyte subsets and white blood cells (WBC) were measured in local hospitals. Heavy metals were measured by GFAAS. Results:Higher blood lead, Cadmium and Chromium levels, WBC, B cell percentage and counts, but lower HBsAb titers, NK cell percentages and counts appeared in the exposed children compared to controls (P<0.05). Generalized Linear Model regression showed negative correlations between HBsAb concentrations and blood lead levels (BLLs), Th (CD4+) cell percentage, and positive correlations with B cell percentage and counts, and NK cell percentage and counts. Generalized Additive Model showed that HBsAb concentrations began to decline dramatically when BLLs reached 15.2 µg/dL in exposed group and 10.9µg/dL in control group. Conclusion: Exposure to e-waste recycling in the community is related to higher blood lead, Cadmium and Chromium exposure and decrease HBsAb titers, NK cell percentages and counts in local children.