10-year trend of 1-hour SO₂ CAAQS metrics in Ontario
10-year trend of 1-hour SO₂ CAAQS metrics in Ontario| Year | 1-hour SO₂ CAAQS Metric |
|---|
| 2012 | 53 ppb |
| 2013 | 55 ppb |
| 2014 | 58 ppb |
| 2015 | 58 ppb |
| 2016 | 55 ppb |
| 2017 | 49 ppb |
| 2018 | 45 ppb |
| 2019 | 42 ppb |
| 2020 | 39 ppb |
| 2021 | 39 ppb |