Settleable matter in a highly industrialized area: Chemistry and health risk assessment.

Settleable particulate matter (SPM) was collected at two sampling points within an urban area highly affected by nearby industrial activities. Total deposition values up to 386 mg ·m-2·d-1 were registered, the majority of samples exceeding the limit value established in the legislation in force in Spain until 2002 (300 mg·m-2·d-1). Dry deposition values showed high variability (8.6-830.3 mg·m-2·d-1). Forty-one metals and metalloids were analysed in the dry fraction of SPM, the main being Fe and Ca (maximums: 304.4 and 68.6 mg·m-2·d-1, respectively), followed by Al, Mg, Na, K, Mn, Ti, P and Zn. Trace elements like As and Pb reached up to 7.3 and 76.3 μg· m-2·d-1, respectively. Strong correlations (r > 0.90, p-value < 0.05) between Fe and other elements (Ca, Mn and Pb) were found at both sampling sites. Scanning electron microscopy confirmed the presence of these particles rich in Fe and Ca, in addition to other components, whose morphologies pointed out to anthropogenic sources. These results combined with meteorology data suggest a common industrial source contributing to the levels of these metals. Furthermore, a human health risk study was carried out to assess the potential carcinogenic and non-carcinogenic risks of exposure to thirteen elements in these particles (Al, As, Cd, Co, Cu, Mn, Mo, Ni, Pb, Sb, Sr, V and Zn). The highest levels of risk seemed to be associated with the presence of As, Pb and Sb.