Health risk assessment of lead contamination in soil, drinking water and plants from marrakech urban area, Morocco

The aim of this study is to investigate lead contamination in food chain and evaluate the consequent health risks to local residents in three different sites in the Marrakech urban area, compared to a rural reference region far from any source of lead contamination. The following three urban sites that have been selected to have different potential routes of lead exposure: a) old unimproved water pipes (the Medina); b) agricultural land irrigated from untreated urban wastewater (El Azzozia); and c) a mining site (Drâa Lesfer region) were considered in this study. Samples were collected from three compartments: drinking water, soils and plants (edible part). The levels of lead contamination in these compartments were measured. Transfer factors of lead from soils to plants and the eventual health risk of this metal were calculated. The results showed that lead concentration in drinking water of all sites was below the drinking water safety limit. However, soils and plants from mining site were heavily contaminated as compared to the other sites. Consequently, the oral intakes of lead from local plant foods may pose a high health risk to local residents in the mining site and in the wastewater irrigation sites.