2-YEAR STUDY IN RATS: Survival, Body Weights, Clinical Findings, and Hematology: Groups of 63 male and 63 female F344/N rats were exposed to 0, 0.15, or 1 mg nickel subsulfide/m(3) (equivalent to 0, 0.11, or 0.73 mg nickel/m(3)) by inhalation for 6 hours per day, 5 days per week for 104 weeks.