Air Pollution & Acid Deposition

Primary Pollutants

harmful chemicals emitted directly into the air from natural and human activities

Sources of Primary Pollution?

Exhaust pipes, smokestack, or other emission source

Examples of Primary Pollutants

Carbon oxides, Nitrous pxides, SO2s, VOCs, and particulates

Secondary pollutants

form when primary pollutants react with molecules in the atmosphere or sunlight to form other kinds of pollutants.. solar radiation provides the energy and water is usually involved

Examples of secondary air pollutants

ozone, components of acid deposition- sulfates and nitrates

types of major air pollutants (carbon)

(CO) carbon monoxide comes from vehicle exhaust, burning of forests, tobacco, and inefficent stoves

CO2- 93% occurs naturally through the carbon cycle; rest from humans, greenhouse gas

Major Air pollutants (nitrogen oxides and nitric aid)

NO- nitrogen oxide comes from engines and coal burning plants, lightning, bacteria;

NO2- nitrous oxide, a reddish brown greenhouse gas is emitted from fertilizers, animal wastes, and burning fossil fuels

Both are components of photochemical smog & acid rain

Major Air Pollutants (SO2, H2SO4)

SO2 (sulfer dioxide) and H2SO4 (sulfiric acid) a third of it occurs naturally as part of the sulfer cycle, and comes from combustion of coal and refinement of oil

sulfer dioxide

is NOT a greenhouse gas

Major Air Pollutants (particulate matter)

small & light enough to float, 62% is from natural sources, 38% is from plowed fields, construction, smoke, coal burning, & vehicles

Some are irritants and others are toxic particulates (lead, cadmium, PCB)

Major Air Pollutants (O3, VOCs, Plants, Gas, RN)

Ozone (O3) is found in the troposphere and is a major component of photochemical smog

Volatile Organic Compounds (VOCs)- most are hydrocarbons… isoprenes, terpenes, methane, natural (plants), and human sources

Humans- rice paddies, landfills, oils and gas wells, cow (gas), solvents

Radioactive Radon (Rn)- found in some types of soil and rock

Natural Emissions

Volcanoes release- sulfer dioxide, particulate matter, CO, and nitrogen oxides

Lightning strikes- create nitrogen oxides

Forest fires- release particulate matter NOx and CO

Living plants- release VOCS

Natural Factors that increase air pollution

* urban buildings slow wind speed preventing dilution with clean air
* hills and mountains reduce the flow of air
* high temperatures
* VOC emissions from certain trees and plants
* Grasshopper effect aka the transfer of pollutants from other regions

Acid Deposition

Acid deposition= deposition with a pH lower than 5.6

Cause: sulfer dioxides and nitrogen oxides are combined with water vapor to form sulfuric and nitric acid

Indirect cause: regional air pollution

Midwest- coal burning power plants

prevailing winds

SOLUTION: CRUSHED LIMESTONE

Harmful effects of Acid Deposition

* respiratory diseases in humans
* leaching of toxic metals from soils into lakes and rivers that can accumulate in animal tissues (fish, birds, and mammals) and can caused stunted growth and eventual death in trees
* kills fish and other aquatic organisms
* structural damage to buildings and metal structures