Trace Metal Content and Health Risk Assessment of PM10 in an Urban Environment of León, Mexico

Trace metal concentrations in PM10 were measured in an urban-industrial site in Leon, Mexico in three different seasons. PM10 were collected in quartz fiber filters of 47 mm diameter using low volume equipment operating with a controlled flow of 5 L min(-1) over 24 h. Mass concentrations were gravimetrically determined and it was found that PM10 samples showed values in excess of the Mexican standard and the established values by WHO during cold dry and warm dry seasons. Morphology of selected particles was studied by SEM-EDS analysis, and the elemental composition was determined. Collected samples were analyzed by atomic absorption spectrometry in order to quantify ambient air concentrations of some trace metals (Cu, Co, Zn, Cd, Fe, Mg, and Mn). Median concentrations of trace metals showed the maximum value for iron (3.079 mu gm(-3)) and the minimum value for Cd (0.050 mu gm(-3)) over the entire period. From the meteorological analysis, it was found that sources located SW and ESE of the sampling site contributed to the levels of trace metals in PM10 in the studied site. The health risk assessment found that the population of Leon is at increased lifetime risk of experiencing cancer because of exposure to these concentrations of PM10 and their trace metal content.