AIR PollutantsAIR Pollutants

• We breathe about 2 gallons of air every minute. • By inhaling polluted air, a typical human lifespan can be

reduced by 1-2 years.

Air Pollution-Introduction to Air Pollutants (7 min)

•https://www.youtube.com/watch?v=UtdKRvWC1yQ-Asian Brown Cloud (2 min)

•https://www.youtube.com/watch?v=qYYK-2sDN4U

-lots of particulates from cars, coal burning and dust, smoke and ash from drought and the clearing and burning of forests from planting crops-the cloud travels-about 25% of particulates, 77% of black carbon and 33% of toxic mercury in skies above LA can be traced to China.

Did You Know….??• Air pollution caused by human activities, including

industrial and energy production, the burning of fossil fuels and increased use of certain types of transport, causes serious health problems for hundreds of thousands of people every year.

• Environmental damage such as acidification, eutrophication, tropospheric (ground-level) ozone and reduced air quality, especially in urban areas, can be a local as well as a trans boundary problem as air pollutants are transported in the atmosphere and harm human health and the environment elsewhere.

What about air pollution?

• What is in air?• How are pollutants classified?• What are the pollutants we are most

concerned about?• How do pollutants get in our air?• How can we reduce pollution?• What is indoor pollution?• How can we reduce indoor pollution?

What is in Air?

Clean air Polluted air• Harmful substances Harmful substances

can be solids, liquids can be solids, liquids or gases.or gases.

• Can be Can be brownbrown or or grey. grey.

• Breathing can be Breathing can be difficultdifficult

• NitrogenNitrogen gas gas• OxygenOxygen gas gas• Small amounts of Small amounts of

argon, COargon, CO22 and and water vaporwater vapor

• Air is clearAir is clear• Breathing is Breathing is easyeasy

POLLUTANTS• Can come from Can come from natural sources natural sources such as such as

volcanoes and dust/pollen from windvolcanoes and dust/pollen from wind• But, most are the result of But, most are the result of human activities human activities

(anthropogenic)(anthropogenic)..

POLLUTANTS• Primary pollutants- Primary pollutants- a pollutant that is put a pollutant that is put

directly into the air by human activity such as directly into the air by human activity such as sootsoot from smoke. from smoke.

• Secondary pollutants Secondary pollutants are formed as a result are formed as a result of a chemical reaction in the air. of a chemical reaction in the air.

Examples are:Examples are: 1. 1. Ozone Ozone that is created when emissions that is created when emissions

from cars react with UV rays from the sun from cars react with UV rays from the sun and then stay in the atmosphere.and then stay in the atmosphere.2. 2. Smog and Acid RainSmog and Acid Rain

Particulates video (4min)

• http://www.teachersdomain.org/asset/ttv10_vid_aerosols/

What Are the Major Outdoor Air Pollutants?

1. Carbon monoxide (CO)

2. Nitrogen oxides (NO) and nitric acid (HNO3)

3. Sulfur dioxide (SO2) and sulfuric acid (H2SO4)

4. Particulate matter - Suspended particulate matter (SPM)

5. VOCs (volatile organic compounds)- organic chemicals that vaporize easily to produce toxic fumes

6. Lead

• Most air pollution in urban areas comes from Most air pollution in urban areas comes from motor vehicles motor vehicles and and industry.industry.

Some natural pollution particulates come from volcanoes, sea spray, and flower pollen

Over 1/3 of our air pollution comes from …

• CARS! Auto emissions have effects on our air.

The main emissions of a car engine The main emissions of a car engine are:are:•NitrogenNitrogen gas (N gas (N22) - ) - AirAir is 78-percent nitrogen gas, is 78-percent nitrogen gas, and most of this passes right through the car engine.and most of this passes right through the car engine.•Carbon dioxide Carbon dioxide (CO(CO22) - This is one product of ) - This is one product of combustion. The carbon in the fuel bonds with the combustion. The carbon in the fuel bonds with the oxygen in the air.oxygen in the air.•Water vapor Water vapor (H(H22O) - This is another product of O) - This is another product of combustion. The hydrogen in the fuel bonds with the combustion. The hydrogen in the fuel bonds with the oxygen in the air.oxygen in the air.•These emissions are mostly harmless, although These emissions are mostly harmless, although carbon dioxide carbon dioxide emissions are believed to contribute emissions are believed to contribute to to global warmingglobal warming. .

• Because the combustion process is never perfect, some smaller amounts of more harmful emissions are also produced in car engines.

• Catalytic converters are designed to reduce all three:

1. Carbon monoxide (CO) is a poisonous gas that is colorless and odorless.

2. Hydrocarbons or volatile organic compounds (VOCs) are a major component of smog produced mostly from evaporated, unburned fuel.

3. Nitrogen oxides (NO and NO2, together called NOx) are a contributor to smog and acid rain, which also causes irritation to human mucus membranes.

The Catalytic ConverterThe Catalytic Converter• Works by causing a Works by causing a chemicalchemical reaction that reaction that

turns exhaust emissions into less harmful turns exhaust emissions into less harmful substancessubstances

• 2NO → N2NO → N22 + O + O22

• 2CO + O2 → 2CO2CO + O2 → 2CO22

The Clean Air Act - 1970

• Gave the Gave the EPAEPA the authority to regulate the authority to regulate automobile emissions. automobile emissions.

• Required the gradual elimination of Required the gradual elimination of leadlead in in gasoline and a decrease in auto emissionsgasoline and a decrease in auto emissions

• Catalytic converters help reduce auto Catalytic converters help reduce auto emissionsemissions

The Clean Air Act• The effects of the Clean Air Act have been

verified with ice cores taken from Greenland.

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• The ice cores show a dramatic rise in sulfur dioxide in the atmosphere starting around 1900.

• Nitrogen oxides begin increasing around 1950.

• Levels of both pollutants

stabilized after the 1970s.

How Can We Reduce Harmful Car Emissions

• Drive less• Drive vehicles that use alternative energy

sources such as Electric vehicles, hybrids, ethanol …

Industrial Air Pollution

• Most industries and power plants use fossil Most industries and power plants use fossil fuels for energy. This burning releases large fuels for energy. This burning releases large amounts of amounts of oxidesoxides into the air such as CO into the air such as CO22, , SOSO22 and NOx and NOx

• Manufacturers of electronic products Manufacturers of electronic products contribute to VOCs from contribute to VOCs from solventssolvents used to used to clean clean circuitcircuit boards and other parts. boards and other parts.

• The Clean Air Act requires industries to use The Clean Air Act requires industries to use scrubbersscrubbers or other air pollution devices. or other air pollution devices.

How do scrubbers work?

• Moves gases through a spray of Moves gases through a spray of water water that that dissolves many pollutants. dissolves many pollutants.

• Electrostatic precipitators – remove Electrostatic precipitators – remove particulatesparticulates by creating an electric charge by creating an electric charge which attracts these larger particleswhich attracts these larger particles

Thermal Inversions• Thermal inversion occurs when a layer of warm

air settles over a layer of cooler air that lies near the ground.

• The warm air holds down the cool air and prevents pollutants from rising and scattering.

Normal Conditions

Thermal Inversion Conditions

Air Pollution History• The Donora Fluoride Fog of 1948

– In late October, the town of Donora experienced a temperature inversion.

– The town is located along the Monongahela River south of Pittsburgh, within a small valley.

– The main employer of the town was a US Steel Zinc smelting plant.

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Donora Fluoride Fog

• Emissions of sulfur dioxide, nitrogen dioxide, and fluoride from the zinc smelting plant began to accumulate.

• The smog became so thick that driving was impossible.

• The plant itself did not cease operations until 4 days later.

• The smog finally broke up as a rainstorm entered the area after 5 days.

Noon in Donora

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• THE LONDON SMOG OF 1952

– London naturally has very calm air, and regularly experiences thick sea fog.

– The weather turned unusually cold, causing the residents to burn greater amounts of coal to heat their homes.

– This combined with a temperature inversion to create a thick smog of sulfur dioxide over the city.

– The fog lasted 5 days, and caused between 4,000- 12,000 deaths.

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SMOG (brown air smog)SMOG (brown air smog)

• When smoke and fog reduce When smoke and fog reduce visibilityvisibility• Smog results from chemical reactions Smog results from chemical reactions

involving involving sunlight, Nitrogen sunlight, Nitrogen oxide and oxide and hydrocarbonshydrocarbons

• AutomobilesAutomobiles and industries are the main and industries are the main causescauses

• Cities that experience the most smog have Cities that experience the most smog have dense dense traffictraffic and are in and are in drydry, sunny areas, such , sunny areas, such as LA, Denver and Mexico Cityas LA, Denver and Mexico City

WHAT DO YOU REMEMBER???

• Name the major air pollutants.• What is the difference between primary and

secondary pollutants?• Name 2 examples of natural pollution and 2

examples of man made. (anthropogenic)• What are the different sources of industrial

pollution and photochemical smog?

Air Pollution Effects on Human Health• Chronic Bronchitis and Asthma (worsened)• Emphysema and Lung Cancer• Air pollutants aggravate respiratory diseases.• Heart attacks and strokes• The young and old are most affected.

• The London Smog in 1952- 4000 people died in only a few days.

Indoor Air PollutionIndoor Air Pollution

• Many people spend as much as 90% of their Many people spend as much as 90% of their days indoors.days indoors.

• Buildings with very poor air quality are said Buildings with very poor air quality are said to have to have sick-building syndromesick-building syndrome..

Some Important Indoor Air Pollutants

Common indoor air pollutants include: Common indoor air pollutants include: •second-hand tobacco smoke; second-hand tobacco smoke; •airborne mold and mildew; airborne mold and mildew; •pet dander; pet dander; •lead-impregnated dust from old paint and some vinyl mini blinds; lead-impregnated dust from old paint and some vinyl mini blinds; •cockroach shedding; cockroach shedding; •Dust mite particles; Dust mite particles; •combustion gases released by stoves, heaters, candles and fireplaces; and combustion gases released by stoves, heaters, candles and fireplaces; and •chemicals released by chemicals released by

– dry cleaned clothes; dry cleaned clothes; – cleaning products; cleaning products; – room deodorizers; room deodorizers; – office supplies; office supplies; – carpets; carpets; – paints and sealers; paints and sealers; – new furniture and pressed wood; new furniture and pressed wood; – personal care products; and personal care products; and – pesticidespesticides

To reduce the levels of indoor air pollution you can: To reduce the levels of indoor air pollution you can: •never allow smoking indoors; never allow smoking indoors; •use less toxic cleaning products; use less toxic cleaning products; •make certain that the indoor space is properly ventilated; make certain that the indoor space is properly ventilated; •reduce levels of cockroach and dust mite particles; reduce levels of cockroach and dust mite particles; •reduce pet dander; reduce pet dander; •avoid or minimize use of pesticides indoors; avoid or minimize use of pesticides indoors; •use low toxicity paints, sealers and caulks; use low toxicity paints, sealers and caulks; •reduce the use of solvent-based dry cleaning and/or air out reduce the use of solvent-based dry cleaning and/or air out dry-cleaned clothes thoroughly before bringing into one's dry-cleaned clothes thoroughly before bringing into one's home; home; •avoid idling an internal combustion engine, such as a car, avoid idling an internal combustion engine, such as a car, lawn mower or fork lift, in an enclosed space or near the lawn mower or fork lift, in an enclosed space or near the entrance to one's home or workplace; and entrance to one's home or workplace; and •change air filters frequently.change air filters frequently.•OPEN WINDOWSOPEN WINDOWS

To reduce the levels of indoor air pollution you can: To reduce the levels of indoor air pollution you can: •never allow smoking indoors; never allow smoking indoors; •use less toxic cleaning products; use less toxic cleaning products; •make certain that the indoor space is properly ventilated; make certain that the indoor space is properly ventilated; •reduce levels of cockroach and dust mite particles; reduce levels of cockroach and dust mite particles; •reduce pet dander; reduce pet dander; •avoid or minimize use of pesticides indoors; avoid or minimize use of pesticides indoors; •use low toxicity paints, sealers and caulks; use low toxicity paints, sealers and caulks; •reduce the use of solvent-based dry cleaning and/or air out reduce the use of solvent-based dry cleaning and/or air out dry-cleaned clothes thoroughly before bringing into one's dry-cleaned clothes thoroughly before bringing into one's home; home; •avoid idling an internal combustion engine, such as a car, avoid idling an internal combustion engine, such as a car, lawn mower or fork lift, in an enclosed space or near the lawn mower or fork lift, in an enclosed space or near the entrance to one's home or workplace; and entrance to one's home or workplace; and •change air filters frequently.change air filters frequently.•OPEN WINDOWSOPEN WINDOWS

Radon Gas• An invisible, odorless, tasteless gas that is radioactive• Radon is one of the elements produced when

uranium decays. Uranium is found naturally in the earth and is most concentrated in porous soils overlying rocks that contain uranium.

• Radon gas can enter homes and stick to dust particles which can then be breathed in.

• The radon decay releases alpha particles which can lead to cancer

ASBESTOS

• Fibers containing silica are used to reinforce cement, to make brake linings, residential siding, garments to protect fire fighters, and in insulation.

• Used because the silica is strong and is heat resistant.

• If these fibers get in the lungs, they can cut and scar them causing asbestosis. Victims have a hard time breathing and often die of heart failure. Mesothelioma is an aggressive cancer of the cells that surround organs such as the heart and lungs.

REVIEW

• Name 3 indoor pollutants.• Name the source and effects of asbestos and

radon.• Name 5 ways to reduce indoor pollutants