Air Pollution

Air Pollution

Can be broken down into outdoor and indoor pollution

First, we need a definition of air pollution – a pollutant is generally considered to be anything that isn’t desired. E.g., smoke, large amounts of dust, ozone are generally considered pollutants. Radon, perfumes, noxious odors can also be considered pollutants.

OUTDOOR AIR POLLUTION

Primary - Dust, smoke particles, nitrogen, carbon etc.
Secondary - Formed when primary pollutants react or combine with one another, or the basic elements.

Smog

Photochemical smog - A mixture of primary and secondary pollutants. Forms when primary pollutants interact under the influence of sunlight.
Industrial smog - Caused by burning coal and oil. Mainly a problem in countries with infant industrial programs.
Vog – type of smog that forms by the interaction of volcanic gasses and the atmosphere in sunlight.
Thermal Inversions

Acid Deposition

What is acid deposition? – SO₂ and NO_x gasses are carried aloft by wind and form secondary pollutants (acids), which are then carried back to earth in wet (snow, rain, fog) and dry (particulate) form.

Acid Deposition - harmful effects
Property / structural damage
Foliage damage
Weakened plant defenses
Contaminated water and damage to aquatic species

E.g., in December of 1952, five days with calm, foggy weather resulted in over 400 deaths attributed to the toxic gasses trapped by the inversion. Many of those gasses were acidic.

INDOOR AIR POLLUTION

1990 - EPA placed indoor air pollution at the top of the list of 18 sources of cancer risk (People spend 70-98% of time indoors)
Cigarette smoking is the single most preventable cause of death and suffering among adults. Kills 8200 people/day - number is expected to triple by 2050.
Sick Buildings - EPA states at least 1/5 of all buildings in US are "sick", i.e., that is they have poor indoor air quality.
Sources of indoor air pollution include: volatile organic compounds (VOCs) that are degassing, smoke, poor ventilation, radon, ozone produced in electrical settings.

EFFECTS OF AIR POLLUTION ON LIVING ORGANISMS AND MATERIALS

Damage to Human Health
Prolonged Exposure - Prolonged exposure can lead to breakdown of natural defenses, leading to lung cancer, asthma, chronic bronchitis, and emphysema.
Deaths - US estimates of annual deaths = 7,000 -180,000. If include indoor air pollution, 150,000 - 350,000.
Costs - According to EPA and American Lung Association, air pollution costs US minimum of $150 Billion annually in health care and lost worker productivity, with $100 Billion of that related to indoor air pollution.

Damage to Plants

Chronic Exposure - Breaks down cuticle, thus leaving a plant less able to adapt to sudden changes in environmental conditions.
Productivity - Overall productivity of European forests has been reduced by ~16%, mostly because of air pollution.

Damage to Aquatic Life

Acid Shock - Caused by sudden runoff of large amounts of highly acidic water, either following heavy snowmelt, or when heavy rains follow a prolonged draught.