Sources of Atmospheric Fine Particles and Mercury in New Jersey

Abstract

Statistical analyses showed that the annual mercury wet deposition levels in New Jersey did not decline substantially despite new regulations that significantly reduced mercury emissions in New Jersey. To explain this and to identify possible sources of air pollution in New Jersey, a receptor modeling study was conducted. The goal of the study was identification of the major sources of fine particles (PM2.5) and mercury (Hg) in New Jersey and investigation of changes in their contributions over time. An advanced factor analysis method, Positive Matrix Factorization (PMF), was used as a receptor modeling tool for the combined mercury and chemical composition particulate data set from Brigantine, New Jersey. Different sources of air pollution, such as coal and oil combustion, metal production, wood combustion, soil, and sea salt emissions, have been identified. Midwestern coal combustion was identified as a major source for PM2.5 in New Jersey. Time series for the three sources – oil combustion source with high loadings of V and Ni, coal combustion source with high loadings of SO4=, and incineration/metal production source with high loadings of Pb and Zn showed a negative trend. Major sources of the different mercury fractions have been identified as well. Time series for some of these sources, related to mercury emissions, showed a negative trend, while others exhibited no trend. Further research is necessary to determine the reasons behind the lack of decline in wet deposition of mercury. The results of the receptor modeling show that the PMF represents a useful and important tool for identifying and quantifying the sources of air pollutants.