18-3 What Is Acid Deposition and Why Is It a Problem?

• Concept 18-3 Acid deposition is caused mainly by coal-burning power plants and motor vehicle emissions, and in some regions it threatens human health, aquatic life and ecosystems, forests, and human-built structures.

Acid Disposition Is a Serious Regional Air Pollution Problem

• To reduce __________ pollution, many coal burning power plants and ore smelters use _________ smokestacks to vent the exhaust from burned fuels high into the atmosphere where _________ can disperse them

• While they do reduce local pollution, they can increase regional air pollution _________________

localtall

wind

downwind

Acid Disposition Is a Serious Regional Air Pollution Problem

• Prevailing winds may carry primary pollutants like _______ and nitrogen oxides _____ as far as 1000 kilometers (_______ miles)

• Along their trip, these compounds form secondary pollutants such as…• Droplets of ______________________ H2SO4 and

_______________________ HNO3

• Particles of acid forming ________________ (SO42-)

and _______________(NO3-) salts

SO2NOx

600

sulfuric acidnitric acid

sulfatenitrate

Acid Disposition Is a Serious Regional Air Pollution Problem

• These acidic substance remain in the atmosphere for _________ days, depending on weather patterns

• They may descend to earth’s surface in two forms…• _________ deposition• Acidic rain, snow, fog, and cloud vapor with a pH of less

than _______• _________ deposition• Acidic particles

• The mixture is called __________ ________________, or often times simply ________ ___________

2-14

wet

5.6dry

acid depositionacid rain

Fig. 18-14, p. 477

WindTransformation to sulfuric acid (H2SO4) and nitric acid (HNO3)

Windborne ammonia gas and some soil particles partially neutralize acids and form dry sulfate and nitrate salts Wet acid deposition

(droplets of H2SO4 and HNO3 dissolved in rain and snow)

Nitric oxide (NO)Sulfur dioxide (SO2) and NO

Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts)

Acid fog

Lakes in deep soil high in limestone are buffered

Lakes in shallow soil low in limestone become acidic

Current and Possible Future Acid Rain Problem Areas

Fig. 18-15, p. 478

Acid Deposition Has a Number of Harmful Effects (1)

• Acid deposition damages statues and building

• It also contributes to human ____________________ diseases

• And can ____________ toxic metals, like lead and mercury, from soils and rocks into ____________ used for drinking water

• These toxic metals can accumulate in the tissues of __________ eaten by people and other

animals

respiratory

leach

lakes

fish

Acid Deposition Has a Number of Harmful Effects (1)

• Acid deposition also harms ________________ ecosystems• Most fish cannot survive in water with a pH less than

______• Releases ____________________ ions from soils that

cause excess _______________ formation in fish gills…clogging their gills

• Scientists are very concerned with the effect of South Asian Brown Clouds on the _________________ Ocean

• Also affects __________ and ________________• Acid deposition leaches essential ____________________

from the soil and releases _____________ metals to the soil

aquatic

4.5aluminum

mucus

Pacific

crops forestsnutrients

toxic

Natural Capital Degradation: Air Pollution Damage to Trees in North Carolina, U.S.

Fig. 18-16, p. 479

Fig. 18-17, p. 480

Solutions

Acid Deposition

Prevention Cleanup

Reduce coal use Add lime to neutralize acidified lakesBurn low-sulfur coal

Increase use of natural gas and renewable energy resources

Add phosphate fertilizer to neutralize acidified lakes

Remove SO2 from smokestack particulates and NOx gases and remove vehicular exhaust NOx from motor

Tax emissions of SO2

18-4 What Are the Major Indoor Air Pollution Problems?

• Concept 18-4 The most threatening indoor air pollutants are smoke and soot from the burning of wood and coal in cooking fires (mostly in less-developed countries), cigarette smoke, and chemicals used in building materials and cleaning products.

Indoor Air Pollution Is a Serious Problem (1)

• In _______ developed countries, the ___________ burning of wood, charcoal, dung, crop residues, coal expose people to dangerous levels of ___________________ air pollution• __________ suffer the greatest risk

Glaring example of the connection between poverty, environmental quality, and human health

less indoor

particulatepoor

Burning Wood Indoors in India

Fig. 18-18, p. 481

Indoor Air Pollution Is a Serious Problem (2)

• Indoor air pollution is also a serious problem for _______________ countries, mostly because of chemicals used in _______________ materials or products• Indoor air pollution is _______________ than outdoor

• The four most dangerous indoor air pollutants in developed countries are…• ________________ smoke• ___________________...in building materials (mobile homes)• Radioactive ____________ gas…seeps into houses from

underground• Very small __________________ particles from various

emissions

developedbuilding

greater

tobaccoformaldehyde

radon

ultrafine

Indoor Air Pollution Is a Serious Problem (3)

• Who is at greatest risk from indoor air pollution?• _____________ under 5 and the ________________• Sick• Pregnant women• People with respiratory disorders or heart problems• Smokers• ___________ workers

Children elderly

factory

Fig. 18-19, p. 482

Chloroform Source: Chlorine-treated water in hot showers Possible threat: Cancer

Para-dichlorobenzene Source: Air fresheners, mothball crystals Threat: Cancer

Tetrachloroethylene Source: Dry-cleaning fluid fumes on clothes Threat: Nerve disorders, damage to liver and kidneys, possible cancer

Formaldehyde Source: Furniture stuffing, paneling, particleboard, foam insulation Threat: Irritation of eyes, throat, skin, and lungs; nausea; dizziness1,1,1-Trichloroethane

Source: Aerosol sprays Threat: Dizziness, irregular breathing

Styrene Source: Carpets, plastic products Threat: Kidney and liver damage

Nitrogen oxides Source: Unvented gas stoves and kerosene heaters, woodstoves Threat: Irritated lungs, children's colds, headaches Benzo- -pyrene

Source: Tobacco smoke,woodstoves Threat: Lung cancer

Particulates Source: Pollen, pet dander, dust mites, cooking smoke particles Threat: Irritated lungs, asthma attacks, itchy eyes, runny nose, lung disease Radon-222 Source:

Radioactive soil and rock surrounding foundation, water supply Threat: Lung cancer

Tobacco smoke Source: Cigarettes Threat: Lung cancer, respiratory ailments, heart disease

Asbestos Source: Pipe insulation, vinyl ceiling and floor tiles Threat: Lung disease, lung cancer

Carbon monoxide Source: Faulty furnaces, unvented gas stoves and kerosene heaters, woodstoves Threat: Headaches, drowsiness, irregular heartbeat, death

Methylene chloride Source: Paint strippers and thinners Threat: Nerve disorders, diabetes

Case Study: Radioactive Radon Gas

• Radon-222 is a colorless, odorless, ______________ gas that is produced by the natural radioactive decay of ____________________, which is found in small amounts in rocks and soils

• If radon-222 seeps up and is released outdoors, it quickly ________________ and decay to harmless levels

• However, radon-222 may seep inside a building through …• ____________ in a building’s foundation• ________________ around sump pumps and drains

radioactive

uranium-238

disperses

cracks

opening

Science: Sources and Paths of Entry for Indoor Radon-222 Gas

Fig. 18-20, p. 483

• Exposure can damage ___________ tissue and lead to lung ________________• Your risk depends on ________________ radon is in your

home and whether you have every ___________• Radioactive radon is the ______________ leading cause of

lung cancer

• Remedies?• ________________ cracks in the foundation• Increasing ___________________• Installing a radon __________________ system

lungcancer

how muchsmoked

second

sealingventilation

mitigation

Review Questions!

• Is acid deposition considered a local or a regional problem?

• What are some of the harmful effects of acid deposition?

• What are the four most dangerous indoor air pollutants in developed countries?

regional

Damage to buildingsHarmful to aquatic ecosystems, crops, forestsHuman respiratory problems, toxic metals

tobacco smokeformaldehyde

Radon-222Ultrafine emission particles