Measurement of polycyclic aromatic hydrocarbons in the air along the Niagara River

Ambient concentrations of polycyclic aromatic hydrocarbons (PAH) and phthalate esters were measured in air along the U.S.-Canadian border and the Niagara river. During two week-long studies in 1982-83, levels of pah species recorded were in the range of 3 ng/cu M to 40 ng/cu M. PAHss with three rings or less were detected in significant proportions in the gas phase, while larger molecules were almost solely in the particulate phase. Sources for pah particulate components appear to be local, while gas-phase components have a more regional character. Benzo-a-pyrene levels were consistent with previous particulate measurements documented along the river since 1981.