Indoor/outdoor particulate matter and health risk in a nursing community home in Sao Paulo, Brazil

The elderly spend more of their daily time indoors, especially at home, and due to this, air quality measurements where they live are extremely important. Thus, this study was conducted to evaluate indoor/outdoor size-segregated particulate matter (PM) mass concentrations, followed by black carbon (rBC) and trace elements analysis and health risk assessment estimate in quasi-ultrafine particles (q-UFP), in a OL nursing home in Sao Paulo, Brazil. The outdoor mass concentrations (32.0 mu g/m(3) for PM10 and 22.8 mu g/m(3) for PM2.5) were higher (p < 0.05) than those indoors (21.6 mu g/m(3) for PM10 and 14.6 mu g/m(3) for PM2.5), indicating the significant influence of outdoor sources reinforced by the strong correlation between indoor/outdoor, r(2) = 0.84 and 0.79 for PM10 and PM2.5, respectively. The daily PM2.5 and PM10 mass concentrations indoors and outdoors exceeded the World Health Organization (WHO) Guidelines during different seasons. The elements S, K and Na were the most abundant in all campaigns, with sulfur the highest, reaching 740 and 722 ng/m(3) outdoors and indoors, respectively. The Lifetime Carcinogenic Risk (LCR) values (2.2 x 10(-5) and 4.6 x 10(-5)/1.9 x 10(-5) and 3.8 x 10(-5)) exceeded the threshold value of 1 x 10(-6) under indoors and outdoors, on mean, for different scenarios (chronic and sub chronic). The particle deposition was found to be 32%, in the respiratory system, higher for elderly males than for females. Our study confirmed that both indoor and outdoor environments may be unsafe for the elderly health and the importance of reducing harmful air pollutants where populations have been living.