Hazard identification and dose response of ingested nickel-soluble salts

People can ingest soluble nickel compounds as a normal constituent of food or as a contaminant in drinking water. This paper presents an assessment of the noncancer and cancer human health risks from ingestion of soluble nickel compounds. A reference dose (RfD) of 8 x 10(-3) mg Ni/kg/day in addition to the amount in food was calculated, based on albuminuria in female rats exposed to nickel sulfate in drinking water for 6 months (A. Vyskocil et al., 1994, Hunt. Exp. Toxicol. 13, 689-693). This RfD is comparable to the current RfD based on decreased body weight in a chronic feeding study in rats (A. M. Ambrose et al, 1976, J. Food Sci. Technol. 13, 181-187). The potential for nickel-induced reproductive toxicity was also taken into account in the derivation of the RfD. There are a number of negative animal bioassays with soluble nickel salts, but all of them have deficiencies that preclude a definitive conclusion. According to EPA's 1996 draft cancer guidelines, the carcinogenic potential of oral exposure to soluble nickel "cannot be determined because there are inadequate data to perform an assessment." (C) 2000 Academic Press.