Health risk assessment of potentially toxic elements in the dry deposition fraction of settleable particulate matter in urban and suburban locations in the city of Gijon, Spain

This study investigates the human health risk of Al, As, Fe, Mn, Ni, Pb, Sb and Sr in the dry deposition fraction of settleable particulate matter (DSPM). Sixty samples were collected at an industrial suburban site ('EMA') and a waterfront urban site (Naval') in Gijon, a coastal city in northern Spain. Up to 4898.4 mg m(-2) d(-1) were measured at the station closer to industrial activity. The levels of the eight elements were greater at this site. Fe and Al were the major constituents, comprising up to 50% of DSPM. The human health risk posed by DSPM was assessed using a U.S.EPA methodology. The level of exposure to the metals/metalloids in this atmospheric pollutant was studied via ingestion, inhalation, and dermal contact. The results showed that ingestion was the main exposure pathway for the residents at the two locations, followed by dermal contact and inhalation. For adults, the non-carcinogenic hazard indexes and the carcinogenic risk levels of the eight elements were within the acceptable levels (1 and 10(-5), respectively). Nevertheless, in the case of children, the non-carcinogenic hazard indexes of Fe and Pb as well as the carcinogenic risk level of As via ingestion were higher than those thresholds. Despite its importance, little research has focused on assessing the human risk posed by metals/metalloids in DSPM. Although there are uncertainties regarding the exposure factors and toxicity values, the outcomes of this study provide useful knowledge for regulatory authorities to establish appropriate mitigation measures to reduce DSPM emissions in urban and suburban environments.

Automated summary

This study investigated the human health risk of metals/metalloids in the dry deposition fraction of settleable particulate matter in two sites in a coastal city in northern Spain. The main exposure pathway for residents was ingestion, and while levels were acceptable for adults, children showed higher levels of hazard indexes and carcinogenic risks for some elements. More research is needed to fully understand the impact of metals/metalloids in DSPM on human health.