Provincial Air Quality Objectives for Nitrogen Dioxide
Nitrogen Dioxide (NO2) is a gaseous pollutant. It is produced along with other nitrogen oxide (NOx) during high-temperature fossil fuel combustion.
Exposure to NO2 affects human health and the environment. For example, long term exposure causes:
- Allergic responses
- Respiratory infections
- Harm to the cardiovascular and reproduction system
Short term exposure can reduce lung function and worsen:
- Respiratory symptoms
- Airway inflammation
Even at lower concentrations, NO2 can be harmful.
NO2 air quality objectives
In November 2021, B.C. adopted the 2020 Canadian Ambient Air Quality Standards (CAAQS) for NO2 as the new Provincial Air Quality Objectives.
This replaced the standards that have been used since 2014.
|Metric or Criteria||Level||Calculation Method|
|1-hour||60 parts per billion||98th percentile of daily 1-hour maximum over three years|
|Annual||17 parts per billion||Average of 1-hour concentrations over one year|