title: Polycyclic aromatic hydrocarbons in the air in the St. Lawrence Basin (Québec).
abstract: High-volume air samples were collected from 1993 to 1996 in rural areas of Québec to investigate on the levels and the vapor-particle partitioning of polycyclic aromatic hydrocarbons (PAHs). Ranges for the mean concentrations of total PAHs (ng m(-3)) were as follows: Villeroy, 3.31-18.92; St. Anicet, 7.57-22.84; and Mingan, 0.50-0.53. Lower molecular weight PAHs predominated at all locations. Particle-gas partition coefficients (Kp) were in good correlation with their vapor pressures (r2 = 0.79-0.97) with slopes deviating from the expected value of -1. The curve of the fractions of PAHs on particles in St Anicet in 1995 fell on that of Lake Superior. In St. Anicet, fractions of phenanthrene, fluoranthene, pyrene, and chrysene on particles were close to those calculated from the soot-air partition coefficient (KSA). At all sites the mean ratios of particulate PAH of the same molecular weight but of very different reactivities were similar during the same sampling days, suggesting that particle-bearing PAHs in Villeroy and Mingan were of the same nature as those found in St. Anicet where adsorption onto soot particles was the major mechanism. Furthermore, the enthalpies of desorption for the predominant PAHs were close at all sites.
authors.affiliation: Meteorological Service of Canada, Atmospheric Toxic Processes Section, Environment Canada, 105 McGill Street, Montréal, Québec, Canada H2Y 2E7.
authors.forename: Barnabé
authors.initials: B
authors.lastname: Ngabé
authors.forename: Laurier
authors.initials: L
authors.lastname: Poissant
mesh_terms: D000388:Air / Q000592:standards; D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D011792:Quebec
chemical_list: D000393:Air Pollutants; D011084:Polycyclic Aromatic Hydrocarbons