1、2022/7/131Air Pollution EffectsLecture 2 Air Pollution Effects Effects on Human Health Effects on Properties Effects on Visibility Effects on Global Warming (Chapter 14) Effects on Stratospheric Ozone Depletion Effects on Human Health Air Pollutants Criteria Pollutants Sulfur oxides (SOx) Fine parti

2、culate matter(細(xì)顆粒污染物PM10, PM2.5) Carbon monoxide (CO) Ozone （臭氧） Nitrogen dioxide （NO2）hazardous air pollutants Asbestos （石棉粉塵） Benzene （苯） Berylium （鈹塵） Coke oven emissions （焦?fàn)t廢氣） Inorganic arsenic （無機(jī)砷） Mercury （汞） Radionuclides （放射性粉塵） Vinyl chloride （氯乙烯） Two Types Effects on Human Health Long-t

3、erm, low-concentration exposures Short-term, high-concentration exposures Acute Effects Industrial accidents The most common air pollution harmful effects dose- response curve Effects on Human Health dose-response curve Dosage Dosage =C - concentration of pollutantst - exposure time Dose-response cu

4、rveDose(Concentration)Response(Harmful effects)No-thresholdthreshold Effects on Human HealthThreshold DefinitionThreshold value represents conditions under which it is believed that nearly all workers may be repeatedly exposed day after day , without adverse effect. Biological MechanismAir pollutant

5、sHuman bodyHarmless degradation productsHarmful degradation products Effects on Human HealthAnimal experiment (white mouse)Laboratory experiments with humansEpidemiological studies of human populations Biological Mechanism Effects on Human Health Effects on PropertiesAcid DepositionAcid Deposition i

6、s the accumulation of potential acid-forming particles on a surface.Acids result from natural causes and human activities.The acid-forming reactants are classified as wet or dry.9Acid rain distribution of in China Effects on Properties Plants Animals Historical monuments11Harmfulness of acid rainmal

7、formed fish due to living in water with low pH valueAbnormal death of large amounts of treessculpture Effects on Visibility Four interactions of light with atmospheric particles come directly to the eyes, r 1 visibility of Scenes We can see something which it can emit light to our eyes , or reflect

8、the light to our eyes. More light photons come to our eyes, more clearly we can see the scene. Examples computer monitor scanning picture Effects on Visibility Distant scene visibility of Scenes Particles between us and the scene scatter sunlight (or moonlight or streetlight ) toward us, which preve

9、nt us from seeing distant scenes clearly. The longer distance, the more particles between us and the scene, the less clearly. Effects on VisibilityGuangzhou in haze Effects on Global WarmingThe Earths surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated wa

10、rming during the past two decades. Climate Green house effectSunlight in the dayOutgoing radiation in the dayOutgoing radiation in the night Most of sunlight(visible) : 0.30.7 m (shorter wavelength radiation) Outgoing radiation: 1 m (longer wavelength radiation) greenhouse gases is transparent for s

11、unlight, absorb longer wavelength radiation). Green house effect Green house effectMain contributors to global warming Impacts of Global WarmingRising global temperatures are expected to raise sea level, and change precipitation and other local climate conditions. human healthmany types of ecosystem

12、sanimalsDesertsforestscrop yieldswater supplies Effects on Global Warming Effects on Stratospheric Ozone Depletion The Earths Atmosphere and Stratospheric Ozone Mount Everest, is about 8.8 km high. Concorde cruises, is at about 16km. Ozone layerO2 + hv - O + O(1)O + O2 - O3 (2)Ozone Reaction Effects

13、 on Stratospheric Ozone Depletion How Ozone Holes are Formed? Effects on Stratospheric Ozone Depletion How Ozone Holes are Formed? Effects on Stratospheric Ozone Depletion How CFCs destroyed Stratospheric zone?(I)ClO + ClO + M-Cl2O2 + MCl2O2 + hv-Cl + ClO2ClO2 + M-Cl + O2 + Mthen:2 x (Cl + O3)-2 x (

14、ClO + O2)net:2 O3-3 O2and(II)ClO + BrO-Br + Cl + O2Cl + O3-ClO + O2Br + O3-BrO + O2net:2 O3-3 O2 Effects on Stratospheric Ozone Depletion Ozone-destroying chemicalsOzone-destroying chemicalsNameUseWhen U. S. production ends*CFCs(chlorofluorocarbons)solvents, aerosol sprays (most spray can uses banne

15、d in 1970s) foaming agents in plastic manufacture January 1, 1996 Halons fire extinguishers January 1, 1994 Carbontetrachloride solvents, chemical manufacture; carbon tetrachloride causes cancer in animals January 1, 1996 Methyl chloroform(1,1,1-trichloroethene) very widely-used solvent; in many workplace and consumer solvents, including auto repair and maintenance products January 1, 1996 HCFCs(hydro CFCs)CFC substitutes, che