Distribution and bioaccessibility of metals in peri-urban parks – metro Vancouver

Abstract

Soil samples collected from 15 peri-urban parks in Metro Vancouver were analyzed for total metals, pH, carbon and bioaccessibility to determine the relationship between point source emission and deposition of metals in surrounding park soils, and potential associated toxicity. Minimal statistical correlation was identified between sources and metal concentrations. Copper and zinc concentrations exceeding the Canadian Council of Ministers of the Environment soil quality guidelines (SQG) for residential/parkland use were identified in two parks. Metal bioaccessibility values were less than 10%, with the exception of Cd (62%), Cu (17%), and Pb (46%). There was no significant correlation between pH and bioaccessibility, while total carbon showed a weak positive correlation with Cd, Cr, Cu, Ni, and Pb bioaccessibility. Low metal concentrations coupled with the low bioaccessibility for the elements that exceeded the SQG suggested that the human health risk associated with ingestion of contaminated soils at the parks studied was minimal.