The concentrations of atmospheric extractable particulate organic matter (EOM) were measured at Sterling Forest, New York and Ringwood, New Jersey during the period 1977 through 1979. The samples were taken on a monthly basis for Sterling Forest and were measured as 3-day composites at Ringwood. The study indicated there was significant variability in the concentrations measured at these rural sites when compared to New York City, which is located 50 miles (80 km) to the southeast. The highest concentrations measured at the rural sites were for the polar fraction (as identified by acetone extractable organic mass). The wintertime levels of EOM were very low when compared to New York City, indicating the lack of many local sources for space heating. The summertime EOM levels, at the rural sites, however, did show episodic excursions, which appeared to be associated with periods influenced by regional photochemical smog. When compared to data taken at remote locations of the world, the average EOM levels observed in this study were higher. This would be expected because the sites are periodically downwind of major industrial and urban centers.