Metabolic profile and assessment of occupational arsenic exposure in copper- and steel-smelting workers in China.

PURPOSE: Analyze the urine arsenic (As) metabolite profiles of workers in copper-and special steel-smelting plants and explore the potential occupationally As exposure as well as the individual arsenicosis risk.

METHODS

A total of 95 male workers from two plants, located in northeastern part of China, were recruited. Information about each subject was obtained by questionnaire. Inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) in urine and airborne As concentrations of working sites were determined.

RESULTS

Airborne As concentrations in copper smelter sites were significantly higher than steel smelter sites. Workers in copper smelter had significantly higher concentrations of iAs, MMA, DMA in urine with creatinine adjustment but a lower value of primary methylation index (PMI) than that of steel-smelting plants workers. The higher proportion of the inorganic form but the lower proportion of DMA form of copper smelter workers was compared to that of steel smelter workers, and the concentration of DMA in steel smelter workers' urine significantly increased linearly with seafood consumption. Seven workers in copper smelter were found to have hyperkeratosis or/and hyper-pigmentation, and their urine showed higher iAs% but lower DMA% and PMI compared to other workers without As dermatosis at the same level of As exposure.

CONCLUSIONS

Release of As dust produced in crude ore extracting and smelting is the main pollution source of As in copper smelter plant. The methylation capacity of As decreases with the increase in As exposure level, and skin damage caused by As is associated with decreasing methylation capacity.