Comparison of Oxidative Properties, Light Absorbance, and Total and Elemental Mass Concentration of Ambient PM sub(2.5) Collected at 20 European Sites

Oxidative properties, light absorbance and total and elemental mass concentration of ambient PM sub(2.5) collected at 20 European Sites were compared. PM suspensions were recovered from filters by vortexing and sonication before dilution to a standard concentration. Light absorbance of the filters was measured with reflectometry. PM oxidative activity varied significantly among European sampling sites. It was observed that the correlations between oxidative activity and all other characteristics of PM were low, both within centers and across communities. Because these novel measures were suggested to reflect crucial biologic mechanism of PM, their use may be pertinent in epidemiologic studies. It is essential to define the appropriate methods to determine oxidative activity of PM.