# Air Quality Health Index (AQHI) - A [[Canada|Canadian]] scale to measure [[air quality]] - 1–10 scale - Designed as a metric for health risk based on different air quality thresholds [^1] - Based on a mixture of pollutants: [^1] - Ground-level ozone (O₃) - Particulate matter (PM_2.5) - Nitrogen dioxide (NO₂) - Does not measure - Odour - Pollen - Dust - Heat - Humidity - Reflects current knowledge of air quality science [^1] - Focused on two populations - General - At-risk - Children - Elderly - Persons with respiratory or cardiovascular conditions | Level | Risk | |:-----:| ------------- | | 1 | Low risk | | 2 | Low risk | | 3 | Low risk | | 4 | Moderate risk | | 5 | Moderate risk | | 6 | Moderate risk | | 7 | High risk | | 8 | High risk | | 9 | High risk | | 10 | High risk | | 10+ | Very high risk | [^1]: [Canada.com – Difference between Air Quality Health Index and Air Quality Index - date modified 2016-03-22](https://www.canada.ca/en/environment-climate-change/services/air-quality-health-index/difference.html)