Student Research: Meenakshi Kushwaha
MPH, Environmental and Occupational Health (EOH), 2015
Childhood Lead Exposure in a Vietnamese Battery Recycling Village
Background: Battery recycling and manufacturing are major sources of occupational exposure to lead. Residents of Dong Mai village in northern Vietnam have been involved in battery recycling since the 1970s. To address pervasive lead contamination a remediation plan was developed by Blacksmith Institute in collaboration with Vietnamese national and local authorities. This is an ongoing study with the primary aim of determining changes in child lead exposures after lead remediation activities and a secondary aim of identifying risk factors for childhood lead exposure.
Methods: All children in the village 6 years of age and younger were eligible and invited to participate in the study. A total of 250 children participated in baseline measurements in December 2013; 209 of the 250 children participated in follow-up assessment in September 2014. Written informed consent was collected from parents/guardians of participants. Parents or guardians of participants also responded to interviewer-administered household survey on involvement in recycling activities, use of personal protective equipment, and personal hygiene of household members including children. For data analysis BLL was categorized based on U.S. CDC recommendations for treatment (≥45 µg/dL). Higher values were split based on the instrument measurement limit (>65 and 45-65 µg/dL) and lower values were split into two categories of approximately equal size (10-19 and 20-44 µg/dL). Bivariate analysis was conducted between categorized BLL and covariates using chi-square, Fisher exact tests, or one-way ANOVA.
Findings: At baseline, all children tested with Lead Care II had elevated BLLs : 24% had BLL >65 µg/dL; other values had mean 35.2 µg/dl (sd 11.5), with lowest value, 6.9 µg/dL. Current recycling at home, involvement of household members in recycling, duration of home-based recycling activities, and proximity to a recycling operation were all significantly associated with very high BLLs. Time spent by child in outdoor environment was also significantly associated with very high BLLs. At the follow-up assessment BLLs displayed a downward trend: >65 (5% follow-up versus 24% baseline), 45-65 (11% versus 17%), 20-44 (56% vs 53%), and 10-19 (26 % vs 6%).
Interpretations: Follow-up BLLs, though still high, point towards favorable impact of lead remediation activities in Dong Mai village. However, this study evaluates remediation activities in only one village. We do not have a control group for external comparison, but we consider this unlikely to be a secular trend.
Funding: Fogarty International Center/NIH D43 TW000642; and Rohm & Haas University of Washington Professorship in Public Health Sciences.