Congenital defects, abortion and other health effects in nickel refinery workers.

Health impairment was investigated by a thorough clinical investigation in a cross-sectional study of 821 male and 758 female workers in a nickel hydrometallurgy refining plant. The average nickel exposure levels were found to be around 0.2 mg/m3 in the electrolysis department and 0.13 mg/m3 in the electrolyte purification department. Corresponding average urinary values for nickel were 16 micrograms/l and 10 micrograms/l, respectively. The most common types of health impairment found were respiratory, skin and cardiovascular diseases. Health impairments, except for respiratory diseases, were found more often in females than in males. The design of the study does not allow comparison with a non-exposed population. Even if there are serious limitations in the statistical and sampling details of the pregnancies and new-born babies, the results suggest adverse health effects at usually accepted exposure levels to nickel. Normal pregnancies were reported in 29% of 356 pregnant nickel workers compared with 39% in 342 local construction workers. Spontaneous and threatening abortions were reported in 16% and 17% of all pregnancies in nickel-exposed workers, compared with 9% and 8%, respectively in the construction workers. Structural malformations were found in about 17% of alive-born infants with nickel-exposed mothers, compared with about 6% in the reference group. Significant increased risks of 2.9, 6.1 and 1.9 for total defects, cardiovascular defects and defects of the musculoskeletal system, respectively, were demonstrated.