PMF input dataset for source apportionment and spatial variation of volatile organic compounds upwind and downwind of a major North American city (Montreal, Canada)

The concentration data was obtained from the National Air Pollution Surveillance Program (NAPS) for four stations in Quebec: Lemieux, l’Assomption, Saint Anicet, Parc Saint Jean Baptiste from January 1, 2014 to December 31, 2026. Sampling frequency varied by site, 24h integrated samples collected every 6 days at Parc Saint Jean Baptiste, every 3 days at Saint Anicet, and 4h integrated samples collected every 3 days at l’Assomption and Lemieux.

Method detection limits (MDL) were obtained from NAPS upon request. For the VOCs with concentrations below the MDL for more than 60% of the samples were removed. For the retained species, missing values were replaced by median concentrations and measured concentrations below MDL were replaced with half of the MDL value.