92 Dermal and inhalable cobalt exposure at Swedish hard metal plants

Introduction Manufacture of hard metal is one major use of cobalt in the work environment. Known health effects of cobalt exposure is asthma, hard metal lung disease, contact allergy and increased risk of cancer. Recent studies has shown that cobalt exposure may occur by penetration through skin even though it is mainly absorbed from the pulmonary tract via inhalation. The relationships between exposure to inhalable cobalt in air and on skin and the uptake in blood and urine and the association between dermal symptoms and dermal exposure was investigated. Methodology Cobalt exposure as inhalable cobalt in the breathing zone and as cobalt on skin with acid wash was measured for 71 workers in two Swedish hard metal production facilities. Uptake of cobalt was determined with samples of cobalt in blood and urine. Correlations between exposure and uptake were analysed. Results Multiple linear regression of cobalt in air and on skin with cobalt in blood showed regression coefficients with cobalt in blood (β = 203, p < 0.0010, and β = 0.010, p = 0.0040) and with cobalt in urine (β = 5779, p = 0.0010, and β = 0.10, p = 0.60). Conclusion The study present statistically significant correlations between exposure to cobalt in air with uptake of cobalt in blood and urine. Cobalt on skin was statistically significant with cobalt in blood but not with urine.