Environmental science A Study of interrelationships Unite 8 Air Quality Issues
Unite 8 Unite 8 Air Quality Issues Air Quality Issues Environmental Science Environmental Science A Study of interrelationships A Study of interrelationships
The Atmosphere Composition -About 99%of the clean, dry air in the troposphere consists of(2) gases: Nitrogen(79%)Oxygen (20%) Water vapor accounts for. 01% to 5% Most of the atmosphere is held close to the earth by the pull of gravitational force, thus it gets thinner with increasing distance from the earth
The Atmosphere • Composition - About 99% of the clean, dry air in the troposphere consists of (2) gases: Nitrogen (79%) Oxygen (20%). – Water vapor accounts for .01% to 5%. – Most of the atmosphere is held close to the earth by the pull of gravitational force, thus it gets thinner with increasing distance from the earth
The Atmosphere As the atmosphere absorbs heat from the earth, it expands and rises When heat is radiated into space Weste Convection currents air cools becomes more dense and flows toward the Trade winds earth
The Atmosphere • As the atmosphere absorbs heat from the earth, it expands and rises. – When heat is radiated into space, air cools, becomes more dense, and flows toward the earth
The Atmosphere Air quality degraded by multiple sources Air pollution includes both aesthetic and human health problems Accumulation uebec of air pollution
The Atmosphere • Air quality degraded by multiple sources. – Air pollution includes both aesthetic and human health problems. Accumulation of air pollution
100 Layers of the Atmosphere 90 80 870 ionosphere 060 850 ------- 40 Stratosphere 30 20 10 0
Primary Air Pollutants Five major materials released directly into the atmosphere in unmodified forms Secondary air pollutants form under reaction of primary pollutants and water or sunlight
Primary Air Pollutants • Five major materials released directly into the atmosphere in unmodified forms. – Secondary air pollutants form under reaction of primary pollutants and water or sunlight
Primary Air Pollutants Carbon Monoxide- Produced when organic materials are incompletely burned Single largest source is the automobile Not a persistent pollutant Hydrocarbons Nitrogen Oxides
Primary Air Pollutants • Carbon Monoxide - Produced when organic materials are incompletely burned. – Single largest source is the automobile. – Not a persistent pollutant. Hydrocarbons Nitrogen Oxides
Primary Air Pollutants Hydrocarbons-Group of organic compounds consisting of carbon and hydrogen Evaporated from automobile fuel or remnants of fuel incompletely burned Catalytic converters used to burn exhaust gases more completely
Primary Air Pollutants • Hydrocarbons - Group of organic compounds consisting of carbon and hydrogen. – Evaporated from automobile fuel or remnants of fuel incompletely burned. Catalytic converters used to burn exhaust gases more completely
Primary Air Pollutants Particulates- Minute pieces of solid materials dispersed into the atmosphere(<10 microns) Smoke. Asbestos. Dust Ash Can accumulate in lungs and interfere with the ability of lungs to exchange gases Sulfur Dioxide(So2)- Sulfur and oxygen compound produced when sulfur-containing fossil fuels are burned Burning coal releases sulfur dioxide
Primary Air Pollutants • Particulates – Minute pieces of solid materials dispersed into the atmosphere (<10 microns). – Smoke, Asbestos, Dust, Ash – Can accumulate in lungs and interfere with the ability of lungs to exchange gases. • Sulfur Dioxide (SO 2 ) – Sulfur and oxygen compound produced when sulfur-containing fossil fuels are burned. – Burning coal releases sulfur dioxide
Primary Air Pollutants Nitrogen Oxides(NO, No2)-Formed when combustion takes place in the e aIr N and o molecules from the air may react with one another
Primary Air Pollutants • Nitrogen Oxides (NO, NO 2 ) - Formed when combustion takes place in the air. – N and O molecules from the air may react with one another
