Studies in the District have found that the concentration of Lead (Pb) associated with small particles in the air (PM2.5) is high compared to suburban areas in New Jersey. In 2008, the EPA established stricter ambient air quality criteria for Lead based on total suspended particles (TSP) and not to exceed 0.15 µm/m3 (for rolling 3 month averaging time). Lead associated with larger sized particles (TSP) in the District has not been well documented thus far. Therefore, measurements are needed to establish baseline Lead concentrations in the air using EPA’s new criteria. The objective is to determine if the District exceeds the new EPA lead criteria when lead is measured as a fraction of TSP. We will be using High Volume air samplers to collect TSP from two locations every six days for a period of one year to determine if the new criteria for lead are exceeded. MERI will also use the established EPA standard operating procedure (SOP) to determine the concentration of lead in the samples.