Uncertainty Calculation in Aerosol Measurements

Abstract

newlineMass measurements of particles in the atmosphere are important for regulatory and scientific newlinepurposes. In nearly all of the countries, particulates and#8804;10 µm in aerodynamic size (PM10) is one newlineof the most significant parameters of National Ambient Air Quality Standards (NAAQS). In newlineIndia, as given in NAAQS, the PM10 regulatory limit is 60 µg m-3 which is based on the annual newlinemean weight of samples (minimum 104) annually at a specific site taken for two/three days in a newlineweek for 24-hour. In this study, the components of uncertainty involved in the filter-based newlinesampling of PM10 along with the gravimetric determination of mass have been calculated. As newlineper the EPA guidelines, PM10 mass was monitored for a year at NPL (National Physical newlineLaboratory), New Delhi from January 2014 to January 2015. Monitoring of PM10 was done newlineusing the gravimetric method. newlinePolyaromatic hydrocarbons (PAHs) are the compound which consists of multiple benzene rings newlinebonded in straight, groups or angular forms. They are also found in atmospheric aerosols. In the newlineatmosphere, they can be emitted primarily as a result of incomplete combustion of natural newlinesources (fossil fuels, forest fires, smoke etc.) or anthropogenic sources (coal burning, vehicular newlineemissions, smoke, etc.) or secondarily by atmospheric processes. Depending on the newlineanthropogenic sources, PAHs may occur in significant concentration in urban and industrial newlineambient air, i.e., bounded with particulate matter (PM). Benzo(a)pyrene (BaP) is among the newlinemost toxic and carcinogenic PAHs. Both PM10 and BaP are among the 12 criteria pollutants newlinelisted in Indian National Ambient Air Quality Standards (NAAQS). BaP concentration in PM10 newlinecollected in a representative site of New Delhi was studied during the year 2014 2015. The newlineuncertainty components in measurements were also estimated along with statistical analysis. iv newlineIn this study, the concentration of metals/element of air quality importance in PM10 were also newlinedetermined. There are three metal pollutants which are list