Air Pollution – Components Lead (Pb) Sources Formerly motor vehicles Transition to unleaded gasoline virtually eliminated this source Industrial plants Smelters Battery manufacturers Human exposure mostly through inhalation of lead in air and dust Food Paint Water

Air Pollution – Components Lead (Pb) Effects Not readily excreted by body Accumulates in tissues, especially kidneys, liver, nervous system, bones Health Anemia Kidney disease Reproductive disorders Neurological problems (seizures, mental retardation, behavioral disorders) Birth defects (CNS damage, retarded growth) High blood pressure  heart disease Environment Deposition on leaves of plants is hazardous to grazing animals and humans (ingestion of meat)

Lead 1990-2010: Pb emissions down 60%

Comparison of growth measures and emissions, 1990-2010

Comparison of National Levels of the Six Criteria Pollutants to the Most Recent NAAQS, 1990-2010 **Ozone and PM2.5 shown relative to standards revised in 2008 and 2006, respectively**

Number of People Living in Counties with Air Quality Concentrations Above the Level of the NAAQS in 2010 www.epa.gov/air/airtrends/2011/index.html

Number of Days on Which Air Quality Index (AQI) Values Were Greater than 100 During 2002-2010 www.epa.gov/air/airtrends/2011/index.html

Air Pollution – Regulation & Legislation History – “Pollution is the price of progress” Air Quality Act (1967) Authorized secretary of HEW to establish air quality regions States given responsibility of adopting and enforcing pollution control standards Controversial – Air pollution doesn’t stop at regional boundaries Failure – Only a few regions were established, and no state had established a full pollution control program Clean Air Act (1970) Established National Ambient Air Quality Standards (NAAQS) Typically annual average concentration or daily maximum concentration Established statutory deadlines for compliance EPA (federal agency) responsible for recommending policy to Congress and monitoring/enforcing policy

Air Pollution – Regulation & Legislation Clean Air Act (1970) Local enforcement left to state governments States allowed to have more stringent pollution standards than EPA “Command and Control” EPA established standards and technology used to achieve standards Non-compliance  heavy fines Clean Air Act Amendments (1990) Market-based approach to achieving NAAQS “Cap and Trade” system Examples Time frames for compliance based on designation of “nonattainment areas” (marginal to extreme) Tailored to specific situations Established possibility of emissions trading Allows economic and technological flexibility

Water Pollution – Sources and Effects Background Oceans – 97% of world’s water Ice & permanent snow – 2% Ground water – 0.6% Provides drinking water for 50% of people in US Sources of water pollution tend to be less centralized and identifiable, compared to sources of air pollution Relatively few pollutants characterized Sources Pollution Point sources Discharge directly into receiving waters Easier to characterize and regulate than NPS’s Non-point sources Pollutants from diffuse sources May vary regionally and seasonally Ex – Chloride from salting streets in winter May be difficult to distinguish natural from anthropogenic effects