| Receptor modeling was conducted using existing polycyclic aromatic hydrocarbon (PAH) deposition data and published PAH source profiles. The PAH deposition data analyzed was collected at Nahant, MA over a period from November 1998 through May 2000, with sampling periods ranging from 2 to 7 days. The sampling was conducted in the coastal town of Nahant in order to estimate atmospheric PAH deposition in the Massachusetts Bay. Source apportionment was estimated using the U.S. EPA Chemical Mass Balance (CMB) Model 8. The published PAH source profiles were adjusted for atmospheric decay using decay factors for each individual PAH species.; Four major sources of PAH emissions were represented in the modeling. The results indicate that four of the primary contributors to atmospheric deposition, with varying proportions, at Nahant are: jet aircraft engines, diesel engines, gasoline automobiles, and wood combustion. The CMB validation statistics indicate that the modeling results are reasonable. However, the lack of consistent; valid source profiles is noted as an area needing further research. |
