Sulphur Dioxide (SO2)
Sulphur Dioxide is a colourless gas consisting of atoms of sulphur and
oxygen. SO2
has an odour of a lit match.
How is it generated?
Sulphur dioxide is generated both naturally and anthropogenically (man-made). Sources
include: burning of sulphurous fuels (coal, diesel, coke, etc.), metal smelting,
pulp and paper mills, petroleum refineries, food preparation, volcanic eruptions.
What Are The Health Effects?
- Perceivable odour.
- At low concentrations it can aggravate chronic respiratory illness.
- Can cause eye, throat, and skin irritation at higher concentrations.
- Damages vegetation through the degradation of chlorophyll (basic building block of all photosynthetic processes).
- Damages rock/stone (eg: deterioration and discolouration of ancient statues).
- Major component to acid rain generation; accounts for about 70% of the total acid rain generated.
Provincial Guidelines:
- The Average Annual Alberta Ambient Air Quality Guideline is 11 ppb (parts per billion)
- The 24-hour Average Alberta Ambient Air Quality Guideline is 57 ppb
- The 1-hour Average Alberta Ambient Air Quality Guideline is 172 ppb
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.
Table of 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 |