Analysis and Modelling of Ambient Air Toxics Pollutants in Canada with Environment Canada AURAMS Model

Abstract

In Canada, air toxic pollutants are regulated under Schedule 1 of the Canadian Environmental Protection Act-1999. As part of the Canadian government’s Clean Air Regulatory Agenda (CARA), Environment Canada is working with Health Canada to develop air quality modelling capabilities to support assessments of health and environmental impacts from mobile source emissions. In current phase, there are 6 compounds of interest: benzene, 1-3 butadiene, formaldehyde, acetaldehyde, acrolein and 1-2-4 trimethylbenzene. Environment Canada’s AURAMS air quality model was modified to explicitly simulate the chemistry of these compounds with the SAPRC07-toxics mechanism. National emissions inventories were processed for air toxics species with source-specific VOC profiles, while on-road mobile sources were explicitly modeled. AURAMS was applied on a 45-km grid spaced domain covering Canada and the US, and over a summer and a winter period. Long-term analysis of >5 years of surface measurements from National Air Pollutant Surveillance (NAPS) Network for 10–54 stations were used to compare with this first model analysis. This paper will focus on the analysis of long-term ambient concentrations of air toxics in Canada, as well as initial results from the AURAMS model with air toxics capability for a summer and a winter period.