AQHI
Moderate
Risk
4

Monitoring

Sulphur Dioxide (SO2)

Sulphur dioxide is generated both naturally and anthropeogenically (man-made), including the processing and combustion of fossil fuels containing sulphur. It is a colourless gas with a pungent odour (similar to a lit match), and can be detected by taste and odour at concentrations as low as 300 ppb.

Sulphur dioxide reacts in the atmosphere to form sulphuric acid and acidic aerosols, which contribute to acid rain (accounts for about 70% of the total acid rain generate). Sulphur dioxide combines with other atmospheric gases to produce fine particles, which may reduce visibility.

Brief exposure to high concentrations of sulphur dioxide and its products can produce human health effects, irritating the upper respiratory tract and aggravating existing cardiac and respiratory disease. Long-term exposure may increase the risk of developing chronic respiratory disease.


What Can We Do?

Conserve Energy. The best way to reduce the amount of Sulphur Dioxide is to reduce the amount of energy you need, thereby reducing the demand for burning the fuel source. Insulating your home properly, wearing sweaters in the winter, using low energy lighting.

Support alternative fuels. Natural gas burns cleaner and is more efficient in some processes. Solar, wind and hydrogen power are all great examples of alternative fuel that would result in a reduction of SO2 production.

Support ‘Emission Scrubbing’ technology. Scrubbers introduce a ‘basic’ compound, usually Calcium Carbonate (Limestone), or Calcium Oxide (Lime) into an effluent stream. The ‘basic’ materials react with the acidic effluent being produced by the process to neutralize the emission and reduce the potential for formation of acid rain.

Recycle Paper. A source of SO2 is pulp and paper mills, by recycling your paper, you can help save the environment as recycling processes are far less detrimental to the environment. However, reducing and reusing your paper is even more environmentally friendly.


Alberta Guidelines

Alberta Environment has adopted the Environment Canada's most rigorous objectives for sulphur dioxide. The Alberta guidelines for ambient air are:

  • 1-hour average of 170 ppb;
  • 24-hour average of 60 ppb;
  • an annual average of 10 ppb

Table of Human Symptoms and Other Effects

Concentration (ppb) Exposure Time Human Symptoms and Other Effects
400,000 Lung edema; bronchial inflammation
20,000 Eye irritaiton; coughing in health adults
15,000 1 hour Decreased mucoduar-y activity
10,000 10 min Bronchospasm
10,000 2 hours Visible foliar injury to vegetation in arid regions
8,000 Throat irritation in healthy adults
5,000 10 min Increased airway resistance in healthy adults at rest
1,000 10 min Increased airway resistance in asthmatics at rest and in healthy adults at exercise
1,000 5 min Visible injury to sensitive vegetation in humid regions
500 10 min Increased airway resistance in asthmatics at exercise
500 Odour threashold
500 1 hour Visibile injury to sensitive vegetation in humid regions
500 3 hours US national secondary ambient air quality standard
200 3 hours Visible injury to sensitive vegetation in humid regions
190 24 hours Aggravation of chronic respiratory disease in adults
172 1 hour Alberta ambient air quality guideline
140 24 hours US national primary ambient air quality standard
70 annual Aggravation of chronic respiratory disease in children
57 24 hours Alberta ambient air quality guideline
30 annual US national primary ambient air quality standard
11 annual Alberta ambient air quality guideline

Get Involved

As an airshed, educating about air quality is an essential part of what we do. It is important to us as an organization to inform through not only sharing air quality data but also providing tips on how we can all do our part to reduce air pollution and serve as environmental stewards at an individual level.

Learn more