Bioaccessibility of metals in Toronto city parks

Abstract

The purpose of this work was to estimate metals bioaccessibility in soil samples from 15 city parks in Toronto, Ontario, Canada. Total metals concentrations were analyzed to identify contaminants that exceeded the Canadian Council of Ministers of the Environment (CCME) guidelines for residential/parkland use. Arsenic, barium, cadmium, cobalt, copper, lead, nickel and zinc were of particular interest as they have been known to have major effects on human health. Metal concentrations were below the CCME guidelines except for lead at three of the parks. Lead, copper and cadmium bioaccessibility in the soil samples as determined by an in-vitro physiologically based extraction test (PBET) were relatively high. Based on linear regression analyses there were no significant relationships between total metals and soil properties such as pH and total organic carbon (TOC). Generally there was negative correlation between metal bioaccessibility and TOC and positive correlation between bioaccessibility and soil pH.