Fig. 2

3-day mean NO₂, O₃, and combined oxidant capacity (O_x and O_x ^wt) and risk of MI. Legend: Risk of emergency room visits for myocardial infarction associated with 3-day mean NO₂, O₃, and combined oxidant capacity (O_x and O_x ^wt) in Ontario, Canada (2004–2011). Risk estimates reflect a 10 ppb change in ambient concentration and all models are adjusted for 3-day mean ambient temperature and relative humidity. Coefficients for NO₂ and O₃ are from two-pollutant models