Palliser Airshed Society

Nitrogen Dioxide (NO₂)

Nitrogen Dioxide is a reactive gas that can often form the reddish-brown smog seen over large cities. The gas is made up of one nitrogen atom and two oxygen atoms.

How Is It Generated?

Motor vehicles account for over 50% of the total NO₂ generated. Any combustion source will emit nitrogen dioxide (including: power plants, chemical plants, industrial processes, vehicles, furnaces, gas stoves, space heaters, etc.). Some natural sources include: volcanoes, lightning, biological decay, oceans.

What Are the Health Effects?

• May cause eye, nose & throat irritation, headaches and potential lung damage.
• Can aggravate heart disease.
• Reduces visibility through the formation of smog.
• Deteriorates fabrics, dyes, metals and rock and stone (through the formation of acid rain).
• Nitrogen Dioxide contributes to about 30% of the acid rain generated and can have major impacts to vegetation through the bleaching and/or killing of leaf tissue.

Provincial Guidelines:

• The Average Annual Alberta Ambient Air Quality Guideline is 32 ppb
• The 24-hour Average Alberta Ambient Air Quality Guideline is 106 ppb
• The 1-hour Average Alberta Ambient Air Quality Guideline is 212 ppb

What Can We Do?

1. Conserve Energy. By reducing your demand on the power generating stations you will help reduce the amount of NO₂ emitted. Also, consider finding alternative forms of transportation (eg: walking, biking, public transit, car pooling) or plan your outings in order to minimize your overall travel distance. Do not allow your vehicle to idle for long periods (eg: car starters).
   
2. Support alternative fuels. Utilizing ‘Greenpower’, like wind, and solar power will reduce the amount of NO₂ being generated.
   
3. Properly insulate your house and body.

Table of Human Symptoms and Other Effects

Concentration (ppb)	Exposure Time	Human Symptoms and Other Effects
300,000	—	Rapid death
150,000	—	Death after 2 or 3 weeks by bronchiolitis fibrosa obliterans
50,000	—	Reversible, nonfatal bronchiolitis
10,000	—	Impairment of ability to detect odour of NO2
5,000	15 min	Impairment of normal transport of gases between the blood and lungs in health adults
2,500	2 hours	Increased airway resistance in healthy adults
2,000	4 hours	foliar injury to vegetation
1,000	15 min	Increased airway resistance in adults with bronchitis
1,000	48 hours	Slight leaf spotting of pinto bean, endive, and cotton
300	—	Brownish color of target — 1 km distant
250	—	Decrease of growth and yeild of tomatoes and oranges
212	1 hour	Alberta ambient air quality guideline
200	8 hours	Yellowing of white fabrics
120	—	Odour perception threshold
106	24 hours	Alberta ambient air quality guideline
100	12 weeks	Fading of dyes on cotton and rayon
100	20 weeks	Reduction of growth of Kentucky bluegrass
32	annual	Alberta ambient air quality guideline
30	—	Brownish color of target — 10 km distant
3	—	Brownish color of target — 100 km distant