PM10 size distribution of metals and environmental-sanitary risk analysis in the city of Torino

The mechanisms responsible for negative biological effects due to airborne particulate matter (PM) exposure are still being studied, however the interactions between metals and biologic systems seem to be of primary importance. The aim of the study was to estimate a healthy risk linked to exposure to airborne PM10 metals by means of an environmental-sanitary risk assessment. Metals PM10 size distribution analysis was carried out in a central site of Torino city – Italy, then the Target Hazard Quotient (THQ) and the Cancer Risk (CR) were applied, according to standard EPA methods. All sampled metals were present on the different PM10 fractions, however some metals were distributed in some specific fractions: ANOVA test shows Cr, Cu, Mo and Pb as differently distributed among the eight fractions, rising the hypothesis of potential effects in specific tracts of respiratory system. Regarding the risk assessment, in general the CR was higher for an adult than for a child, conversely the THQ resulted higher for a child. While the concentrations of all the sampled metals appeared to be under control, their presence in the different PM10 fractions and their THQ and CR provided indications related to the body districts potentially in contact with these substances.