Skin Lead Contamination of Family Members of Boat-caulkers in Southern Thailand

Abstract

Powdered lead oxide (Pb₃O₄) is used in the wooden-boat repair industry as a constituent of the caulking material. This study compared skin lead of household members of caulkers’ and control homes, and examined the relationship of household member’s skin lead with household floor lead loading (FLL) and dust lead content (DLC). FLL and DLC were measured in 67 caulkers’ houses and 46 nearby houses with no known lead exposure. In each household, wipe specimens of skin lead were obtained from one selected family member. Hand lead loading (HdLL) and foot lead loading (FtLL) were significantly higher in family members of caulkers than controls (geometric mean 64.4 vs. 36.2 μg m^-2; p=0.002 and 77.8 vs 43.8 μg m^-2; p=0.002, respectively). This pattern mirrored FLL and DLC, which were also higher in caulkers’ than in control houses (geometric mean 109.9 vs. 40.1 μg m^-2; p<0.001 and 434.8 vs 80.8 μg g^-1; p<0.001, respectively). Multiple linear regression modelling revealed FLL to be a better predictor than DLC for HdLL in all age groups and for FtLL in adult family members. In conclusion, skin lead levels are elevated in family members living in a lead-exposed worker’s house and are related to the levels of household lead contamination.