SOIL INVESTIGATION AND HUMAN HEALTH RISK ASSESSMENT FOR NICKEL IN COMMUNITY SOILS NEAR A FORMER NICKEL REFINERY IN SOUTHERN ONTARIO, CANADA

摘要

A nickel refinery operated from 1918 to 1984 in a community in southern Ontario In September 2000, soil nickel levels from a single residential property were found to exceed 9750 ppm As a result, the Ontario Ministry of the Environment (MOE) sampled and analyzed almost 2000 soil samples collected from about 200 properties adjacent to the former nickel refinery Results indicated that surface soil nickel levels ranged up to 17,000 ppm, and that the soil metal levels were variable between properties The Ministry conducted a human health risk assessment (HHRA) for seven metals (antimony, beryllium, cadmium, cobalt, copper, lead, nickel) and arsenic found in the surface soils The ministry's HHRA examined total exposure to contaminants through a number of possible pathways, such as (1) incidental ingestion of the soil or dust (indoor and outdoor), (2) home-grown backyard fruit and vegetables, (3) drinking water and supermarket food, (4) dermal contact with soil or dust (indoor and outdoor), and (S) inhalation of ambient air (indoor and outdoor) The predominant form of nickel in these soils was nickel oxide (at least 80% of the total nickel, on average) The HHRA established a soil nickel intervention level of 8000 ppm based on noncancer endpoints, which was intended to protect toddler-aged children The report finds this soil intervention level should not pose immediate or long-term risks to other age groups