Air pollution - chapter 18

Who is at greatest risk from indoor air pollution?

Children under 5 and the elderly

Sick

Pregnant women

People with respiratory disorders or heart problems

Smokers

Factory workers

Define Atmosphere

is the whole mass of air surrounding the earth

Define Troposphere

the innermost layer of the atmosphere

Contains about 95% of the earth’s air and extends about 11 miles above the earth’s surface 

What is found in clean air? 

78% nitrogen 

21% oxygen

less than 1% is argon

0.035% is carbon dioxide 

Water vapor in the air varies

Define Stratosphere

the second layer of the atmosphere, extending from 11 miles to 30 miles

Contains ozone (O3) = filters out 95% if incoming harmful ultraviolet radiation

What is the difference between the ozone in the stratosphere and the ozone in the troposphere?

Stratospheric ozone is “good” because it acts as a protective layer absorbing UV radiation

Tropospheric ozone is “bad” because at ground level it acts as a pollutant

What is air pollution?

occurs when the concentration of a normal component of the air or a new chemical added to or formed in the air builds up to the point of causing harm to humans, plants, animals, and materials

What are the major types of outdoor air pollutants? (classes)

Carbon oxides

Sulfur oxides

Nitrogen oxides

Volatile organic compounds (VOCs)

Suspended particulate matter (SPM)

Photochemical oxidants

Radioactive substances

Hazardous air pollutants (HAPs)

Carbon Monoxide (CO) 

Colorless, odorless gas that is poisonous to air-breathing animals 

Major Human sources: cigarette smoking, burning of fossil fuels. About 77% comes from motor vehicle exhaust 

Nitrogen Dioxide (NO₂)

Reddish-brown irritating gas that gives photochemical smog its brownish color; in the atmosphere can be converted to nitric acid (HNO3) a major component of acid deposition 

Major Human Sources: fossil fuels burning in motor vehicles and power and industrial plants

Environmental effects: reduces visibility; acid deposition of HNO3 can damage trees, soils, and aquatic life in lakes

Property damage: HNO3 can corrode metals and eat away stone on buildings, statues, and monuments; NO2 can damage fabrics 

Sulfur Dioxide (SO2)

Colorless, irritating; forms mostly from the combustion of sulfur containing fossil fuels such as coal and oil; in the atmosphere can be converted to sulfuric acid, a major component of acid deposition

Major human sources: Coal burning in power plants and refineries

Environmental effects: reduces visibility; acid deposition of H2SO4 can damage trees, soils, and aquatic life in lakes

Property damage: SO4 and H2SO4 can corrode metals and eat away stone on buildings, statues, and monuments; SO4 can damage paint, paper and leather

Suspended particulate matter

Variety of particles and droplets small and light enough to remain suspended in atmosphere for short periods to long periods 

Major human source: Burning coal in power and industrial plants, burning diesel and other fuels in vehicles, agriculture, unpaved roads, construction

Environmental effects: reduces visibility; acid deposition of H2SO4 droplets can damage trees, soils, and aquatic life in lakes

Property damage: Corrodes metal; soil and discolors buildings, clothes, fabrics and paints a