Pollution Characteristics and Human Health Risk of Potentially Toxic Elements Associated with Deposited Dust of Sporting Walkways During Physical Activity

Sporting walkways are planned features designed to facilitate physical exercise in urban areas. Potentially toxic elements (PTEs) associated with deposited dust (DD) of urban sporting walkways (USWs), suburban sporting walkways (SSWs) and residential sporting walkways (RSWs) in Jeddah, Saudi Arabia, were measured and interpreted in relation to concentration, spatial distribution, pollution level and human health risk. The elemental concentrations followed a similar pattern, but were generally lower than those in road dust. Pb, Zn, Cu, Cd, and As had elevated Crustal Enrichment Factors (>10), ranging up to 185 for Cd. Except for Fe, ∑PTE concentrations were in the following order: USWs (1431 mg/kg) > SSWs (1073 mg/kg) > RSWs (892 mg/kg). Based on the spatial pattern and enrichment factor, and ecological risk values, sporting walkways (SWs) had moderate to heavy pollution levels of Cd, As, Pb, Zn and Cu, and heavy to extreme pollution level of Cd in USWs. Cd presented a high ecological risk, accounting for 85% of the summed ecological risk indices of the elements with elevated concentration. Carcinogenic and non-carcinogenic risks for children and adults follow the order: USWs > SSWs > RSWs. Ingestion was the main pathway for carcinogenic and non-carcinogenic risks, well exceeding that for the dermal and inhalation pathway. Most risks to human health were generally within the acceptable range, although risks to children were generally higher than those to adults, by a factor of 5.5 for non-carcinogenic risk. Incremental Lifetime Cancer Risks for individual elements did not exceed 10−4 for any element.