Risk Assessment of Metals in Community Gardens: A Case Study in Winnipeg, Manitoba, Canada

Fresh produce is an important component of maintaining cognitive and physical health, particularly for children. A mechanism to increase access to fresh produce is the construction of urban and community gardens. While reducing barriers to nutritious food, the soil of the community garden can contain contaminants (e.g., metals) depending on the location of construction and how the garden was constructed. This study measured concentration of seven metals (As, Cd, Cr, Cu, Pb, Mn, and Ni) measured in soil from 83 community gardens across the City of Winnipeg in Manitoba, Canada. Concentrations in soil were used to create distributions for environmental exposure and estimated daily intake, which were used to determine the percentage of the distributions that exceeded soil quality guidelines and acceptable daily intakes, respectively. Greater than 5% of the environmental exposure distribution exceeded cadmium, lead, and manganese soil quality guidelines from the Canadian Council for Ministers of the Environment. Greater than 5% of the estimated daily intake distribution for children exceeded the Health Canada’s tolerable reference value for arsenic Overall, this study showed that the concentration of the metals in soil from gardens around the City of Winnipeg pose a de minimis risk to environmental and human health..