Nickel and its compounds: Evaluation of risks to health from environmental exposure in Canada

Abstract

In this assessment of nickel as a Priority Substance under the Canadian Environmental Protection Act, available data on exposure and potential health effects of various forms of nickel likely to be present in the general environment were critically evaluated. Metallic nickel was considered to be “unclassifiable with respect to carcinogenicity”, due to the limitations of identified studies. Concentrations of total nickel in ambient air in Canada are more than 5,000 times less than levels of metallic nickel which induced minimal effects in experimental animals. Each of oxidic, sulphidic and soluble nickel has been classified as “carcinogenic to humans”, based on the sufficient weight of evidence of carcinogenicity in occupationally exposed populations. Based on comparison of concentrations of total nickel in air to the estimated potency of these forms of nickel to cause cancer (combined), the priority for analysis of options to reduce exposure in the general environment to oxidic, sulphidic and soluble nickel is considered to be moderate to high, compared to that of other substances assessed in the Priority Substances Program. In addition, a Tolerable Daily Intake or Concentration for non‐carcinogenic effects for soluble or oxidic nickel could be less than exposure in relevant environmental media in Canada. Available data also indicate that nickel (mostly soluble compounds) induces contact dermatitis in a proportion of the population.

Notes

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