Chapter 18: Air Pollution

A mixture between smoke and fog that produces unhealthy urban air.

proposed stricter emission standards for diesel- powered vehicles.

Concentrations high enough to harm human health or alter the climate.

Similar composition to the troposphere, with 2 exceptions.

Filters 95 % of harmful UV radiation and allows us and other life to exist on land.

National emission standards for 188 hazardous air pollutants.

reddish brown gas, formed as fuel burnt in the car, potent oxidizing agent, include Nitric acid in the air.

Acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth.

organic compounds (hydrocarbons) that evaporate easily, usually aromatic.

particles suspended in air (<10 um)

mostly in industrialized and /or urban areas.

Created by sunlight acting on NOx and VOC, photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products.

Similar composition to the troposphere, with 2 exceptions

Filters 95% of harmful UV radiation and allows us and other life to exist on land

Concentrations high enough to harm human health or alter the climate

From reactions of primary pollutants

a big threat to the poor

NO2

ground level O3

CO

Pb

PM10 (PM 2.5)

SO2

(VOCs)

colorless, odorless, heavier than air, 0.0036% of the atmosphere

binds tighter to Hb than O2, mental functions, and visual acuity, even at low levels

carbon oxides (CO2, CO)

9 ppm

reddish brown gas, formed as fuel burnt in the car, potent oxidizing agent, include Nitric acid in the air

acid rain, lung and heart problems, decreased visibility (yellow haze), suppresses plant growth

fossil fuels combustion @ higher temperatures, power plants, forest fires, volcanoes, bacteria in soil

Nitrogen oxides (NOx)

0.053 ppm

colorless gas with an irritating odor

produces acid rain (H2SO4), breathing difficulties, eutrophication due to sulfate formation, lichen and moss are indicators

burning high sulfur coal or oil, smelting or metals, paper manufacture

sulfur oxides

0.3 ppm (annual mean)

particles suspended in air ( <10 um)

lung damage, mutagenic, carcinogenic, teratogenic

burning coal or diesel, volcanoes, factories, unpaved roads, plowing, lint, pollen, spores, burning fields

dust, soot, asbestos, lead, PCBs, dioxins, pesticides

50 ug/m3 (annual mean)

colorless, unpleasant odor, a major part of photochemical smog

lung irritant, damages plants, rubber, fabric, and eyes, 0.1 ppm can lower PSN by 50%,

Created by sunlight acting on NOx and VOC, photocopiers, cars, industry, gas vapors, chemical solvents, incomplete fuel combustion products

photochemical oxidants

organic compounds (hydrocarbons) that evaporate easily, usually aromatic

eye and respiratory irritants; carcinogenic; liver, CNS, or kidney damage; damages plants; lowered visibility due to brown haze; global warming

vehicles (largest source), evaporation of solvents or fossil fuels, aerosols, paint thinners, dry cleaning

HAPs (Hazardous Air Pollutants)

grayish metal

accumulates in tissue; affects kidneys, liver, and nervous system (children most susceptible); mental retardation; possible carcinogen; 20% of inner city kids have [high]

particulates, smelters, batteries

toxic or heavy metals

1.5 ug/m3 2 million tons enter the atmosphere/per year

2C + O2 → 2CO

C + O2 → CO2

N2 + O2 → 2NO

2NO + O2 → 2NO2

S + O2 → SO2

A mixture between smoke and fog that produces unhealthy urban air

Indoor burning of wood, charcoal, dung, crop residues, coal

1970, 1977, and 1990 created regulations enforced by states and cities

National emission standards for 188 hazardous air pollutants

Toxic Release Inventory