Presentation on theme: "Chapter 12, Section 1: What Causes Air Pollution? Standards: SEV3a"— Presentation transcript:
1 Chapter 12, Section 1: What Causes Air Pollution? Standards: SEV3a Air & Air PollutionChapter 12, Section 1: What Causes Air Pollution?Standards: SEV3a
2 What is the normal composition of air? 78% Nitrogen21% oxygen1% various other gases likeArgonCarbon dioxideWater vapor
3 What is air pollution?Any harmful substance that builds up in the air to unhealthy levels.Can be natural: pollen, dust, gases from volcanoesMostly human caused: car exhaust, coal-fired power plants, industrial pollution, etc.
4 What is the difference between a primary and secondary pollutant? Primary pollutantPut directly into air by human activitiesEx: Sulfur dioxide released from burning fossil fuel.Secondary pollutantPrimary pollutants react with other primary pollutants or water vapor to make a new substanceEx: Sulfur dioxide mixes with water in atmosphere and causes acid rain.
5 What are the 5 primary air pollutants? Carbon monoxideNitrogen oxidesSulfur dioxidesVolatile Organic CompoundsParticulate Matter
6 1. Carbon Monoxide (CO) Description: Primary Source: Effects: Odorless, colorlessPoisonousFrom incomplete combustion of fossil fuelsPrimary Source:Vehicles (cars, trucks, buses)Industrial processesEffects:Blood can’t carry oxygen as well, feel sleepy & disoriented; can cause death
7 2. Nitrogen Oxides (NOx) Description: Primary Source: Effects: Can be yellowish gasForms under high tempsPrimary Source:Vehicles (cars, trucks, buses)Power plantsIndustrial boilersEffects:Brownish haze from smog comes from NOxSome acid precipitationMakes body vulnerable to respiratory disease & cancer
9 4. Volatile Organic Compounds (VOCs) Description:Organic chemicalsVaporize readilyForm toxic fumesPrimary Source:Vehicles (cars, trucks, buses)Burning fossil fuelsEffects:Contribute to smog formationHarm plantsLinked to cancer
10 5. Particulate Matter (PM) Description:Tiny pieces of liquid or solid matterPrimary Source:Construction, agriculture, forestry, firesVehicles, power plants & Industrial processesEffects:Form clouds & reduce visibilitySmall pieces can be inhaled & clog respiratory systemLinked to cancerCorrode metal & erode buildingsDivided into:Fine particulate matter (PM 2.5)- from burning fossil fuels; worst because can be inhaled deeper into lungsCoarse particulate matter (PM10)- incinerators, mining, cement plants
11 How long have air pollution problems been around? As early as 2000 years ago, people complained of “foul air”Air pollution problems became worse around the Industrial Revolution of the 1800’s when fossils fuel usage increased and no standards existed for how much pollution could be emitted.Weather History: The Great Smog of London
12 What are two main sources of air pollution? Motor Vehicle EmissionsIndustrial Air Pollution
13 What are Motor Vehicle Emissions? Fumes & particulates produced from the burning of gasoline in vehicles1/3 of air pollution comes from gasoline burned by vehicles.Clean Air Act-regulates vehicle emissionsBanned lead in gasoline- lead pollution has decreased by 90% in US.Catalytic converters clean exhaust gasEPA says vehicles today burn fuel 35% more efficiently and with 95 % fewer emissions (except CO2) than they did 30 years ago.
14 What are Zero-Emissions Vehicle (ZEV) Programs? Established in CA, MA, ME, NY, & VTOffer rebates, tax incentives, closer parking, use of special HOV type lanes for ZEVsTypes of ZEVs:Electric cars- plug in to rechargeHybrid cars- run on both gas and electricMethanol fuel cell cars
15 What are Industrial Air Pollutants? Any industry or power plant that burns fuel to produce energyPower plants produce2/3 of all SO2 emissions1/3 of all NOx emissionsVOCs are common typeFrom dry cleaning fumesOil refineriesChemical plantsCar repair shops
16 What are Industrial Air Pollutants? Clean Air Act requires one of the following:Scrubbers installed in smoke stacks to control air pollutionGases move through spray of water that dissolves the pollutantElectrostatic PrecipitatorsUse static electricity to attract particulates from burning of fossil fuels
17 What is smog?Air pollution that hangs over urban areas and reduces visibility.Car exhaust reacts with air & sunlight to make ground level ozone.Ozone reacts with more car exhaust to make smog.Smog in Beijing, China (~2min)
18 What is a Temperature Inversion? Circulation keeps air pollution from reaching dangerous levels.If a warm air mass traps a cool air mass it will trap pollution with it.Usually common in cities surrounded on 3 sides by mountains.Mountains trap the air.Donora, PA (1948)- 18 people died when temperature inversion trapped SO2 & HF pollution being released from a local steel mill.
19 You should be able to…Name 5 primary pollutants & give important sources for each.Name the 2 major sources of air pollution in urban areas.Describe the way in which smog forms.Define the term temperature inversion. Explain how temperature inversion traps pollutants near Earth’s surface.
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