Chapter 18: Air Pollution

Smog

Smog

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

EPA

proposed stricter emission standards for diesel- powered vehicles.

Air pollution

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

Stratosphere

Similar composition to the troposphere, with 2 exceptions.

Ozone layer

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

NAPs

National emission standards for 188 hazardous air pollutants.

Properties of nitrogen dioxide

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

Effects of nitrogen dioxide

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

Properties of VOCs

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

Properties of particulate matter

particles suspended in air (<10 um)

Human sources

mostly in industrialized and /or urban areas.

Sources of ozone

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

Stratosphere

Similar composition to the troposphere, with 2 exceptions

Ozone layer

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

Air pollution

Concentrations high enough to harm human health or alter the climate

Secondary pollutants

From reactions of primary pollutants

Indoor pollution

a big threat to the poor

Nitrogen Dioxide

NO2

Ozone

ground level O3

Carbon monoxide

CO

Lead

Pb

Particulate Matter

PM10 (PM 2.5)

Sulfur Dioxide

SO2

Volatile Organic Compounds

(VOCs)

Properties of carbon monoxide

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

Effects of carbon monoxide

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

Class of carbon monoxide

carbon oxides (CO2, CO)

EPA Standard of carbon monoxide

9 ppm

Properties of nitrogen dioxide

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

Effects of nitrogen dioxide

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

Sources of nitrogen dioxide

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

Class of nitrogen dioxide

Nitrogen oxides (NOx)

EPA Standard of nitrogen dioxide

0.053 ppm

Properties of sulfur dioxide

colorless gas with an irritating odor

Effects of sulfur dioxide

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

Sources of sulfur dioxide

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

Class of sulfur dioxide

sulfur oxides

EPA Standard of sulfur dioxide

0.3 ppm (annual mean)

Properties of particulate matter

particles suspended in air ( <10 um)

Effects of particulate matter

lung damage, mutagenic, carcinogenic, teratogenic

Sources of particulate matter

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

Class of particulate matter

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

EPA Standard of particulate matter

50 ug/m3 (annual mean)

Properties of ozone

colorless, unpleasant odor, a major part of photochemical smog

Effects of ozone

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

Sources of ozone

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

Class of ozone

photochemical oxidants

Properties of VOCs

organic compounds (hydrocarbons) that evaporate easily, usually aromatic

Effects of VOCs

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

Sources of VOCs

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

Class of VOCs

HAPs (Hazardous Air Pollutants)

Properties of lead

grayish metal

Effects of lead

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

Sources of lead

particulates, smelters, batteries

Class of lead

toxic or heavy metals

EPA Standard of lead

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

Carbon monoxide

2C + O2 → 2CO

Carbon dioxide

C + O2 → CO2

Nitric oxide

N2 + O2 → 2NO

Nitrogen dioxide

2NO + O2 → 2NO2

Sulfur dioxide

S + O2 → SO2

Smog

A mixture between smoke and fog that produces unhealthy urban air

Developing countries

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

Clean Air Acts

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

NAPs

National emission standards for 188 hazardous air pollutants

TRI

Toxic Release Inventory