Campus–Community Partnership to Characterize Air Pollution in a Neighborhood Impacted by Major Transportation Infrastructure

Abstract

This study investigates air quality in a Toronto community located between an airport and an expressway. A community science approach was adopted for data collection and interpretation, and a partnership was formed between a local neighborhood association, university researchers, the municipal government, and the local airport authority. Community scientists placed low-cost sensors on outdoor balconies and inside homes for 28 weeks between 2020 and 2022, measuring particle number (PN) concentrations of particulate matter (PM) with diameters between 0.5 and 2.5 μm. Indoors, the PN concentrations increased during cooking and other activities. During periods with minimal indoor activities, indoor levels closely followed the outdoor signal. Median indoor/outdoor (IO) ratios varied between 0.4 and 0.87 across sampling months. Median outdoor PN concentrations varied from 1 to 4 #/cm³ and were influenced by local and regional sources. Outdoor PN concentrations were significantly correlated to PM_2.5 and nitrogen dioxide at a downtown reference station; the latter suggests that traffic emissions from the nearby expressway contribute to PN concentrations in the neighborhood. An analysis of outdoor ultrafine particle (UFP) data collected at a single location suggests that the airport is a source of UFP in the neighborhood. Community engagement was enabled through involvement in study design, execution, and knowledge mobilization.