The impact of aerosol particulate matter of mean mass aerodynamic diameter <=2.5 um (PM 2.5 aerosols), on health, visibility, and compliance with EPA's regional haze regulations is a growing concern. Techniques that can better characterize particulate matter are required to better understand the constituents, causes and sources of PM 2.5 aerosols. Measurement of the 14C/C ratio of the PM 2.5 aerosols, the absence of 14C in fossil carbon materials and the known 14C/C levels in contemporary carbon materials allows use of a two component model to derive contemporary and fossil carbon contents of the particulate matter. Such data can be used to estimate the relative contributions of fossil fuels and biogenic aerosols to the total aerosol loading. Here, we report measurements carried out on the radiocarbon-to-total carbon ratio of PM 2.5 aerosols of collected using total suspended particulate Hi-vol aerosol samplers on quartz fiber filters. Comparisons of 3-month summer and 3-month winter sampling periods (from 4 remote sites) suggest that the ratio of contemporary and fossil carbon contents do not vary significantly by season. However the contemporary and fossil loading did vary by site indicating different percentages of carbon inputs from the sites. An urban site had the highest fossil carbon aerosol loading which was not completely unexpected considering is location. This dataset suggests that control of anthropogenic sources of fossil carbon aerosols may result in little reduction in carbonaceous aerosol loading at the more remote sites.
See more of Biogeochemistry and Environmental Geochemistry II
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)