Primary and Secondary Pollutants
Primary Pollutants
- Primary pollutants are pollutants that are directly emitted into the air
- Examples (percent of total air pollution): carbon monoxide, volatile organic compounds, nitrogen oxides, sulfur oxides, particulates, and CFCs
Secondary Pollutants
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Criteria Pollutants and Air Toxics
What are the criteria pollutants?
(Botkin & Keller, 2007)
(Botkin & Keller, 2007)
What are air toxics?
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What are examples of air toxics?
(Botkin & Keller, 2007) |
Acid Rain
Causes
The process:
Effects
The process:
- Sulfur dioxide (SO2) and nitrogen oxides (NOx) are emitted and released into the atmosphere from industrial processes and automobile emissions.
- These compounds react with oxygen and water vapor in the atmosphere to produce sulfuric acid (H2SO4) and nitric acid (HNO3).
- The acids are transported by winds and reach the Earth's surface as acid precipitation, which can be rain, fog, snow, or dry depositions.
- Sulfur dioxide is mainly produced by stationary sources: power plants and industrial processes that burn fossil fuels
- Nitrogen oxides are mainly produced by stationary and mobile sources: power plants and automobiles
Effects
- Deaths of trees from decreased soil pH (increased soil acidity)
- Habitat loss from loss of trees
- Loss of nutrients in soil from increased vulnerability of trees to disease and damage
- Increased sunlight exposure and temperature of underlying soil from damage to tree leaves and needles
- Damage to aquatic species by limiting development and causing death
- Loss of nutrients in lakes from dissolution of nutrients and chemicals
- Toxicity and increase of heavy metals in lakes (Botkin & Keller, 2007)
Case Study
More than 90% of Chinese cities do not meet regulation standards for national air quality standards. Chinese standards for air quality are already low compared to the limit recommended by the World Health Organization. The worst ranked cities were Henan, Hubei and Hebei. All the cities house major industries that require a lot of coal to power the plants. Because coal releases everything from particulate matter to CO2 and SO2, it is really no wonder that the industrializing cities of China cannot meet the goals. Although some progress has been made since the last 2 years, Chinese cities still have a long way to go before catching up to other developed nations' standards. (Wong, 2015)
http://www.nytimes.com/2015/04/22/world/asia/hundreds-of-chinese-cities-dont-meet-air-standards-report-finds.html?ref=topics&_r=0
http://www.nytimes.com/2015/04/22/world/asia/hundreds-of-chinese-cities-dont-meet-air-standards-report-finds.html?ref=topics&_r=0