The atmosphere is composed of 78% nitrogen (N2), 21% oxygen (O2), 0.9% argon (Ar), 0.03% carbon dioxide (CO2), and trace amounts of other gases.

Acid deposition is the end product of reactions between sulphur oxides (SOx), nitrogen oxides (NOx) and water in the atmosphere. Acid deposition reaches the earth as precipitation (wet deposition: aci [..]

Acidification is the process of changing into an acid or becoming more acidic (i.e., having lower pH). For example, acid rain causes soils and lakes to become more acidic.

Acid rain forms when the pollutants sulphur dioxide (SO2) and nitrogen oxides (NOx) mix with water to form acids that fall as precipitation (fog, rain or snow). This is referred to as "wet deposi [..]

An Air Quality and Health Advisory is a notice to the general public warning them that air quality will be poor. This allows people to plan their activities to reduce risk of exposure for themselves o [..]

An air quality forecast is a prediction of what the air quality is likely to be over the next few days. It is similar to a weather forecast, and even needs to use the weather forecasts to make the pre [..]

An air quality index is a simple scale that assigns numbers and values (good, fair, poor, very poor) based on the potential effects of the ambient (outdoor) concentration of air pollutants. Learn more [..]

Ambient air quality is also known as outdoor air quality. It does not refer to indoor air quality or to emissions discharged from a source (such as a stack or a vehicle).

Ambient monitoring measures the concentrations of pollutants in outdoor air. Learn more about ambient monitoring in Nova Scotia.

Buffering capacity is the ability of water and soil to resist changes in pH. Low levels of alkalinity in the water and soil in Nova Scotia mean the province has a low acid buffering capacity and is un [..]