Page ‹#›Local Air PollutionIn 2000 Octoberthe orbiting SpaceShuttle Discoveryphotographedupstate New Yorkjust at sunset.Visible is goldensunlight reflectingfrom two of theGreat Lakes (Erieand Ontario), andseveral of theFinger Lakes.Between the cloudsat the top andground at thebottom, however,is a trapped layerof smog.Is Air Pollution a Significant Problem?Is Air Pollution a Significant Problem?• 40% of deaths now linked to EnvironmentalProblems. That is likely to grow as we begin toexperience more health effects of climate change.• Poor people and minorities are typically exposedto higher pollution levels.• In the poorest regions of the world, about one infive children will not reach the age of fiveprimarily due to environmentally related diseases.Source:a study published in Bioscience.The Local Pollution ProblemCriteria Pollutants• EPA began not by controlling the most toxicsubstances, but rather by controlling moreconventional pollutants to which many morepeople were exposed. (Remember the third step inthe four-step risk assessment process?)• These conventional pollutants have becomeknown as criteria pollutants. These are called“criteria pollutants” because the process of controlbegan with the production of “criteria documents”which set out how these were to be controlled.Page ‹#›Consequences of Exposureto Criteria Pollutants• Particulates — Potent respiratory irritants. Can impair lungfunction by damaging tissue.• SO2— Respiratory irritant. Ecological damage. Damage tomaterials. Component of acid rain.• Ozone ( O3) —Attacks cells and breaks down tissues,particularly lung tissue. Also a toxin to plants.• NOx — Constriction of airway; reduced resistance to infection;increases sensitivity of asthmatics. Component of acid rain• CO – Binds to hemoglobin in blood, preventing adequate oxygentransport to cells.• Lead — Circulatory, reproductive, nervous and kidney damagein adults. Impaired mental development in children.Sources of Criteria Pollutants7%79%5%9%CO45%50%3%2%NOx88%4%8%0%SO26%46%43%5%VOC37%26%25%12%PM-10TransportationFuel combustionIndustrialMisc.Hazardous Pollutants• Toxic air pollutants, also known as hazardous airpollutants, are those pollutants that are known orsuspected to cause cancer or other serious healtheffects, such as reproductive effects or birth defects,or adverse environmental effects.• Some 188 chemicals are listed as hazardous airpollutants. Examples of toxic air pollutants includebenzene, which is found in gasoline;perchlorethlyene, which is emitted from some drycleaning facilities; and methylene chloride, which isused as a solvent and paint stripper by a number ofindustries.Human Exposure Pathwaysfor Hazardous PollutantsHuman Exposure Pathwaysfor Hazardous Pollutants• Breathing contaminated air.• Eating contaminated food products, such as fish fromcontaminated waters; meat, milk, or eggs from animalsthat fed on contaminated plants; and fruits and vegetablesgrown in contaminated soil on which air toxics havebeen deposited.• Drinking water contaminated by toxic air pollutants.• Ingesting contaminated soil or peeling paint. Youngchildren are especially vulnerable.• Touching (making skin contact with) contaminated soil,dust, or water (for example, during recreational use ofcontaminated water bodies).PolicyPolicyHow are these Pollutants Controlled?Page ‹#›Policy for ControllingCriteria Pollutants: The Targets• EPA sets ambient standards.• Primary standard based upon human health.• Secondary standards set limits to protect public welfare,including protection against decreased visibility, damage toanimals, crops, vegetation, and buildings.• In principle they should be stringent enough to protect eventhe most vulnerable members of society.• The standards are reviewed periodically to determine whetherthe latest evidence suggests that changes would beappropriate. I will illustrate both the science and politics ofthose reviews in a minute.Policy for Controlling Criteria Pollutants:Reaching the Targets I• States are required to establish enforceable plans(known as State Implementation Plans [SIPs] ) tomeet these standards in their area. (Sanctions fornoncompliance include removing eligibility forfederal funds or EPA imposing a SIP on the state.)• Generally states have relied on emissions standards(limits on specific discharge points) to fulfill thisobligation, though increasingly emissions tradingis being used.Policy for Controlling Criteria Pollutants:Reaching the Targets IIPolicy for Controlling Criteria Pollutants:Policy for Controlling Criteria Pollutants:Reaching the Targets IIReaching the Targets II• Stricter emissions standards are required forthose sources located in those areas (knownas nonattainment areas) where the ambientstandards are being violated.• Via the New Source Review (NSR), newsources or sources undergoing majormodifications typically face more stringentstandards than older sources.Nonattainment areasNonattainment areasThe Offset PolicyThe Offset Policy• The Los Angeles Dilemma• The EPA Proposal• The Offset Alternative ( a credit EmissionsTrading Policy)• New entrants must buy 1.2 tons of credit for every tonemitted.• Purchased from existing sources who voluntarilycontrol more than their legal requirements.• Made economic growth part of the solution rather thanpart of the problemControversies During the Current BushAdministration: The Devil IS in the DetailsControversies During the Current BushAdministration: The Devil IS in the Details• Revising the Smog and Particulate Ambient Standards• The “threshold” dilemma• Nondelegation and Consideration of Costs• The new revision last week (to 0.075ppm)• The New Source Review Revisions• The “routine maintenance” exception.• The “Clear Air Mercury Rule”• The EPA rule set the cap at 38 tons per year by 2010 and15 tons per year in 2018 (much later and much less thanwould have been achieved by hazardous pollutant rules) .• Substitutes emissions trading for emissions standards.• Overturned by the court in February of this year.Page ‹#›Hazardous Air Pollutants• Prior to 1990, 33 substances controlled. 1990Amendments to Clean Air Act brought 188substances under control.• EPA responsible for identifying all emitting sourceswhich emit more than 10 tons of any single listedsubstance in a year or 25 tons of any combinationof listed substances.• For each identified