Factorization methods applied to characterize the sources of volatile organic compounds in Montreal, Quebec.
OBJECTIVE
The study objective was to assemble emission characteristics of the sources of the ambient volatile organic compounds (VOCs) and to elaborate methods of organizing them into the sources' chemical profiles.


METHODS
The UNMIX--sensor modeling method from the U.S. Environment Protection Agency (EPA)--was used to process the VOC concentration data acquired over the years 2000-2009 for 175 VOC species in 4 air quality monitoring stations in Montreal, Quebec.


RESULTS
The method enabled to assess VOC emissions from the typically distributed sources existing in urban environment and VOC occurrences characterizing the local, or point-like, sources. The distributed sources were inextricably associated with hydrocarbons from exhaust, heavier hydrocarbons from contaminated urban soil, fugitive evaporations of gasoline and liquefied petroleum gases (LPG), leakage from the industrial and commercial use of solvents, and the inert, ozone depleting gases permeating urban atmosphere. The sources' profiles were charted involving 60-120 VOC species per source. Spatial distribution of the sources was examined.


CONCLUSIONS
The UNMIX application and the source profiling methods, by building robust chemical profiles of VOC sources, provided information that can be used to assign the measured VOC emissions to physical sources. This, in turn, provides means of assessing the impact of environmental policies, on one hand, and of industrial activities on the other hand on VOC air pollution.
University of Québec at Outaouais, Gatineau, Canada (Department of Computer Science). eporada@hotmail.com.
Eugeniusz
E
Porada
Ottawa University, Ottawa, Canada (Department of Mathematics and Statistics). tkousha@uottawa.ca.
Termeh
T
Kousha
D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution; D004784:Environmental Monitoring; D007221:Industry / Q000706:statistics & numerical data; D011792:Quebec / Q000453:epidemiology; D012997:Solvents / Q000032:analysis; D014186:Transportation / Q000706:statistics & numerical data; D001335:Vehicle Emissions / Q000032:analysis; D055549:Volatile Organic Compounds / Q000032:analysis*
D000393:Air Pollutants; D012997:Solvents; D001335:Vehicle Emissions; D055549:Volatile Organic Compounds
UNMIX; principal components; pulp industry; receptor modeling; source profile; volatile organic compound