The historical record of air pollution as defined by attic dust

The use of undisturbed attic dust as a tool for reconstructing historical air pollution was evaluated in this study. Dust collected from the attic of 201 houses in New Jersey, built between 1879 and 1995, was analyzed for lead with ICP-MS to validate the use of this method. The results were matched to an estimated pattern of the lead concentrations in attic dust, that was based upon historical data on lead gasoline consumption and emissions into the ambient air. In spite of the numerous uncertainties implied in such a comparison, the pattern of lead concentrations found in the attic dust approximated, within intervals of about 10 years, the time course of the lead emissions into the air. 137Cs concentrations were measured in the attic dust samples using gamma spectrometry to investigate the possibility of a local source contaminating the ambient air in Dover Township, NJ. No statistical differences in 137Cesium concentrations were found between the attics in Dover Township and other locations in NJ. The 137Cs concentrations measured in all locations were found to increase with the age of the house. The observed dependence of 137Cs concentrations on the age of the house could be explained primarily by the patterns of radionuclide fallout that has occurred over time because of above ground nuclear weapons testing during the 1950s and 1960s.