Uptake and toxicity of nickel and other metals in crops grown on soil contaminated by a nickel refinery

Abstract

Severe contamination of vegetation and soil by nickel, copper, and cobalt has been observed in the vicinity of a nickel refinery in Southern Ontario. Nickel concentrations in excess of 26000 parts per million (PPM) have been found in surface soil near the refinery and soil concentrations exceeding 100 ppm Ni are found over 8 km downwind of the refinery. Foliage samples from trees growing within 1 km of the refinery frequently exceed 200 to 300 ppm Ni, with lesser amounts of Co and Cu. Despite these high concentrations of Ni, overt metal toxicity symptoms are confined to a few extremely susceptible native species such as silver maple (Acer saccharinum L.), and to susceptible crops such as oats, lettuce, and cabbage. Uptake and toxicity of Ni and other metals were studied in crops growing on a muck farm located about 1 km east of the refinery, where the Ni content of the organic soil ranged from approximately 2000 to 10000 ppm. Growth of crops such as onions, potatoes, celery, cabbage, and lettuce was sever...