Dates Of Important Discoveries Made During The Scientific Revolution

Air: The atmosphere and major pollutants

2 innermost layers of the atmosphere, troposphere which supports life and stratosphere that contain the ozone layer.

- Troposphere 5-11 miles above earth’s surface, 75% 80% earth’s mass, weather and climate.

- Stratosphere ozone layer

Air pollution: presence of chemicals in the atmosphere in concentrations high enough to harm climate.

2 sources of pollution:

- Natural sources: wild-fires and volcanic eruptions, volatile organic chemicals released by plants.

- Human sources: most occur industrialized, urban areas (people, cars) Mobile: motor vehicles. Stationary: power plants and industrial facilities.

Primary pollutants: chemicals or substances emitted directly into the air from natural processes and human activities, at concentrations high enough to cause harm. Directly released into atmosphere. C, NO, HC.

Secondary pollutants: harmful chemical formed in the atmosphere, by reactions between primary pollutants with one another.

Carbon oxides (CO, CO2)

- Carbon monoxides: colorless, highly toxic. Forms by combustion of carbon containing materials. Sources: vehicles, burning forests, tobacco smoke. Combines with hemoglobin in erythrocytes reducing the ability to transport O2 to other tissues.

- Carbon dioxide: colorless, 93% is the result of carbon cycle, the rest from burning fossil fuels, alters greenhouse effects.

Nitrogen oxides & nitric acids (NOx, HNO3)

- Nitric oxide: N and O reacts under high combustion temperatures in autos and industrial plants, some bacteria also produce it. Reacts with O to form Nitrogen dioxide with H2O to form nitric acid or nitrate salts.

Play a role in formation of photochemical salts (mix of pollutants formed under the influence of sunlight) car smoke

Sulfur dioxide & sulfuric acid (SO4, H2SO4)

- Sulfur dioxide: irritating odor, 1/3 from natural sources, rest from combustion of coal in power and industrial plants. Can be converted into aerosol. Reduce visibility, health, crops, and buildings.

Particulates (SPM)

- Suspended particulate matter: variety of solid and liquid matter small and light enough to remain on the air. Most from natural resources (sea-salt, dust) and the rest from human sources. Lead and cadmium can cause genetic mutations, cancer.

Ozone (O3): Happens naturally because UV light. Is a pollutant.

Volatile organic compounds (VOCs)

Organic compounds that exists as gases in the atmosphere or that evaporates from sources on earth. Hydrocarbons only by cities, emitted by plants and bacteria CH4 methane, greenhouse gas 20 times more effective at warming the atmosphere. 1/3 from natural sources, the rest from human activities.

Industrial Smog: burning coal, sulfur dioxide, sulfuric acids, suspended particles.

Photochemical smog: sunlight + cars. VOCs +

...