Cancer risk from arsenic and chromium species bound to PM2.5 and PM1 e Polish case study

Özet

The aim of this study was to determine ambient concentrations of As(III) and As(V); Cr(III) and Cr(VI)species - bound to PM1 and PM2.5 and to assess the incremental lifetime cancer risk associated with theexposure to those elements. Beyond risk analysis, this work presents the results of As(III) and As(V)separation optimization using slurry extraction combined with HG-AAS spectrometry. PM samples werecollected at Katowice urban traffic site (Poland) in 2010, during the winter and summer period. Twentyfour hours (24-h) ambient concentrations of fine PM-bound As(III) þ As(V) varied in the range 0.46e11.76 ng/m3 and for Cr(III) þ Cr(VI) 4.41e21.08 ng/m3. Higher concentrations of As-bearing particleswas observed in winter compared to summer period, while chromium total concentrations showed noseasonal variations. A greater shares of Cr(VI) in Crtot concentrations was observed in non-heating(summer) period and explained by greater intensity of oxidative reactions in the atmosphere, leadingto more effective oxidation of Cr(III) into Cr(VI) species. Although speciation analyses showed that morethan 60% of the total arsenic and chromium appears to be in less toxic As(V) and Cr(III) forms, theprobability of cancer development due to exposure to those elements was even one case per 10,000 ofexposed population and above the limits recommended by US EPA. By treating the risk as the sum of theexposures posed exclusively by Cr(VI) þ As(III) we obtained the ILCRtot value 2-fold lower compared tothe exposure caused by Crtot þ Astot, which indicate the importance of speciation inclusion into riskcalculations