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Visualizing and forecasting the association of air quality and health outcomes in Ontario, Canada

Liang S, Zhu J, McGihon R, Terebessy E, Ge E, Su Y, Fong I, To T. Can Geogr. 2021; 65(3):382-9. Epub 2021 Jan 13. DOI:

Research has shown that air pollution is associated with risks of development and worsening of chronic diseases. The Air Quality Health Index (AQHI) is a numerical scale that reports air quality and health risk, and includes messages that advise on health risk reduction actions according to AQHI levels. Our study aimed to (1) characterize geographical variations between air pollution (AQHI) and health outcomes (incidence, prevalence, and health services use) of asthma, COPD, diabetes, and hypertension; (2) forecast the trend of associations using observed data; and (3) develop visualization tools that help the public identify risks of air pollution and health outcomes. Observed trends of AQHI and health outcomes from 2003 to 2014 were plotted and forecasted up to 2025, while maps showed their geographical variations. Overall, the highest incidence and prevalence of each disease were observed in regions with higher annual mean AQHI. Chronic diseases' acute health services use was higher in northern Ontario, while physician office visits were higher in southern Ontario. The positive correlations between AQHI and health outcomes in Ontario suggests that increasing public awareness of potential health risks of air pollution is important, especially among people with chronic diseases.