AP ENVIRONMENTAL SCIENCE UNIT 7 (ATMOSPHERIC POLLUTION)

what air pollutants does coal combustion release?

carbon dioxide, sulfur dioxide, toxic metals, and particulates

what is released from the combustion of fossil fuels? what does this product do? what are some additional pollutants released from fossil fuel combustion?

-nitrogen oxides; they lead to the production of ozone, formation of photochemical smog, and convert to nitric acid in the atmosphere - causing acid rain

-other pollutants: carbon monoxide, hydrocarbons, and particulate matter

how can air quality be affected by the burning of fossil fuels (mainly diesel fuels)?

through the release sulfer dioxide (SO2)

Clean Air Act

-primary U.S. federal law regulating air emisssions from stationary and mobile sources to protect public health and the environment, it always the environmental protection agency (EPA) to set air quality standards for pollutants

-through this act, the EPA regulated the use of lead, particularly in fuels, which dramatically decreased the amount of lead in the atmosphere

what are the six common pollutants set by the environment protection agency (EPA)

ground-level ozone, carbon monoxide, nitrogen oxide, sulfur dioxide, lead, particulate matter

primary pollutants

harmful substances emitted directly into the atmosphere from specific sources

secondary pollutants

harmful substances that form in the atmosphere through chemical reactions between primary pollutants, sunlight, water vapor, or other compounds

explain how photochemical smog is formed

when nitrogen oxides and volatile organic hydrocarbons react with heat and sunlight to produce a variety of pollutants

what time of day is nitrogen oxide produced?

early in the day

why time of day and year are ozone concentrations at peak and why?

the afternoon and summer because ozone is produced by chemical reactions between oxygen and sunlight

volatile organic compounds (VOCs)

-carbon-based chemicals that evaporate or sublimate at room temperature (examples: formaldehyde and gasoline)

-trees are a natural source of VOCs

why does photochemical smog often form in urban areas?

there is a large number of motor vehicles

how can photochemical smog be reduced

through the reduction of nitrogen oxides and VOCs

how can photochemical smog affect human health?

respiratory problems and eye irritation

explain thermal inversion

during thermal inversion, the normal temperature gradient in the atmosphere is altered as the air temperature at the Earth’s surface is cooler than the air at higher altitudes, trapping pollutants at ground-level (leads to poor-air quality)

what does thermal inversion do to pollution?

it traps it close to the ground, especially smog and particulates

how does CO2 appear naturally in the atmosphere? (three processes)

respiration, decomposition, and volcanic eruptions

carbon monoxide

indoor air pollutant classified as an asphyxiant (causes suffocation)

examples of indoor air pollutants that are classified as particulates

asbestos, dust, and smoke

where can indoor air pollutants come from?

natural sources, human-made sources, and combustion

what are some common natural source indoor air pollutants?

radon, mold, dust

what are some common human-made indoor air pollutants?

insulation, VOCs from furniture, paneling, and carpets; formaldehyde from building materials, furniture, upholstery, and carpeting; and lead from paints

what are some common combustion air pollutants?

carbon monoxide, nitrogen oxides, sulfur dioxide, particulates, and tobacco smoke

radon-222

a naturally occurring radioactive gas that is produced by the decay of uranium found in some rocks and soils

how can radon gas infiltrate homes (two ways)?

-as it moves up through the soil and enters homes via the basement or cracks in the walls or foundation

-it is also dissolved in groundwater that enters homes through a well

what can exposure of radon gas lead to?

radon-induced cancer (second leading cause of lung cancer in America)

methods of reducing air pollutants include (three)…

regulatory practices, conservation practices, and alternative fuels

vapor recovery nozzle

an air pollution control device on a gasoline pump that prevents fumes from escaping into the atmosphere when fueling a motor vehicle

catalytic converter

an air pollution control device for internal combustion engines that converts pollutants (CO, NOx, and hydrocarbons) in exhaust into less harmful molecules (CO2, N2, O2, H2O)

hydrocarbons

organic compounds composed of exclusively carbon and hydrogen (they can be toxic to human health and key source of greenhouse gas emissions)

wet scrubber

industrial pollution control device that remove particulate matter and gases from industrial exhaust streams by bringing them into contact with a scrubbing liquid such as water or chemical solution

dry scrubber

industrial pollution control device that removes harmful gases from exhaust streams by bringing them into contact with dry reagants or sorbents instead of liquid

what two methods are used to reduce air pollution from coal-burning power plants?

scrubbers and electrostatic precipitators

electrostatic precipitators

a high-efficiency filtration device that removes fine particles, such as dust and smoke, from industrial gas streams of air

where does acid rain and deposition come from?

nitrogen oxides and sulfur dioxides from anthropogenic and natural sources in the atmosphere

nitric oxides that cause acid deposition come from?

motor vehicles and coal-burning power plants

sulfur dioxides that cause acid deposition come from?

coal-burning power plants

acid deposition mainly affects what communities?

those that are downwind from coal-burning power plants

acid deposition

the mix of wet (rain, snow, fog) and dry (particle, gas) acidic components that fall to the Earth from the atmosphere

what are the consequences of acid rain and deposition

acidification of soils and bodies of water and corrosion (deterioration) of human-made structures

what is an example of how regional differences in soils and bedrock can affect the impact that acid deposition has on a region

limestone bedrocks ability to neutralize the effect of acid rain on lakes and ponds

noise pollution

sound at level high enough to cause physiological stress and hearing loss

sources of noise pollution in urban areas

transportation, construction, and domestic and industrial activity

effects of noise pollution on animals in ecological systems

stress, the masking of sounds used to communicate or hunt, damaged hearing, and causing changes to migratory routes