Effects of air pollution
Tue, Jan 27, 2009 at 02:40 PM
[ header = Introduction]
In the 1970s, the acute and visible pollution problems of our air and water and the burgeoning problems of hazardous waste disposal pointed us toward controlling and managing the wastes that we could see. EPA developed standards, promulgated regulations and enforced the law with an emphasis on end-of-pipe solutions. These actions had a measurable and positive effect on environmental quality.
In the 1980s, more diffuse and subtle sources of pollution and better methods of detection increased awareness of how ubiquitous and long-lived our waste problems are. Difficult-to-control sources of pollution and recognition of the global nature of environmental issues brought the concept of pollution prevention as a compelling response to the prospect of further contamination. Pollution prevention was a basic reorientation of the nation's approach to pollution that would prevent problems before they occurred.
What causes air pollution?
• Combustion of fuels for power and heat
• Other burning such as incineration or forest fires
• Industrial/commercial processes
• Solvents and aerosols
• Highway vehicles: cars, trucks, buses and motorcycles
• Off-highway vehicles such as aircraft, boats, locomotives, farm equipment, RVs, construction machinery and lawn mowers
Other air pollutants
• Carbon dioxide
Primary types of air pollutants
• Carbon monoxide (CO)
• Volatile organic compounds (VOCs)
• Oxides of nitrogen (NOx)
• Sulfur dioxide (SO2)
• Particulate matter (PM10)
• Lead (Pb)
Carbon monoxide (CO)
• Odorless, colorless gas
• Caused by incomplete combustion of fuel and air
• Most of it comes from motor vehicles
• Reduces the transport of oxygen through the bloodstream
• Affects mental functions and visual acuity, even at low levels
• Improvements are being made but there are still problems
Volatile organic compounds (VOCs)
• General term for a wide range of hydrocarbon compounds
• VOCs result from combustion processes and evaporation of gasoline vapors, solvents, etc.
• They contribute to global warming
• In sunlight, they combine with NOx
to form ozone (smog)
• Ozone irritates eyes, aggravates respiratory ills, damages crops
• The ozone problem is the one affecting the most people today
Oxides of nitrogen (NOx)
• Nitrogen dioxide is the prominent one (it's the yellow-brown color in smog)
• NOx results from high temperature combustion processes, e.g. cars and utilities
• They affect the respiratory system
• They play a major role in atmospheric reactions
• Overall levels unchanged but transportation sources are cleaner
• Long known as one of the worst toxics in common use
• Emitted from gasoline additives, battery factories and nonferrous smelters
• Affects various organs and can cause sterility and neurological impairment, e.g. retardation and behavioral disorders
• Infants and children especiallysusceptible
• Control of mobile sources has been exceptionally successful
Particulate matter (PM10)
• PM10 is a general term for tiny airborne particles e.g., dust, soot, smoke
• Primary sources are fuel-burning plants and other industrial/commercial processes
• Some are formed in the air
• They irritate the respiratory system and may also carry metals, sulfates, nitrates, etc.
• Some overall decreases seen but trends may be masked by meteorological changes
Sulfur dioxide (SO2)
• This term is used for a number of compounds containing sulfur
• Primarily caused by burning of coal, oil and various industrial processes
• They can affect the respiratory system
• They react in the atmosphere to form acids, sulfates and sulfites
• Substantial reductions due to controls at the sources and through use of low sulfur fuels
[ header = Air pollution legislation ]
The Clean Air Act
• Most people now live in urban areas
• Growth results in air pollution
• Air pollution endangers living things
• Prevention and control at the source was appropriate
• Such efforts are the responsibility of states and local authorities
• Federal funds and leadership are essential for the development of effective programs
Pollution Prevention Act of 1990:
"The United States of America annually produces millions of tons of pollution and spends tens of billions of dollars per year controlling this pollution.
"There are significant opportunities for industry to reduce or prevent pollution at the source through cost-effective changes in production, operation, and raw materials use. Such changes offer industry substantial savings in reduced raw material, pollution control, and liability costs as well as help protect the environment and reduce risks to worker health and safety.
"The opportunities for source reduction are often not realized because existing regulations, and the industrial resources they require for compliance, focus upon treatment and disposal, rather than source reduction; existing regulations do not emphasize multi-media management of pollution; and businesses need information and technical assistance to overcome institutional barriers to the adoption of source reduction practices.
"Source reduction is fundamentally different and more desirable than waste management and pollution control. The Environmental Protection Agency seeks to address the historical lack of attention to source reduction.
"As a first step in preventing pollution through source reduction, the Environmental Protection Agency has established a source reduction program which collects and disseminates information, provides financial assistance to States, and implements the other activities provided for in the Pollution Prevention Act of 1990.
"Congress declared it to be the national policy of the United States that pollution should be prevented or reduced at the source whenever feasible; pollution that cannot be prevented should be recycled in an environmentally safe manner, whenever feasible; pollution that cannot be prevented or recycled should be treated in an environmentally safe manner whenever feasible; and disposal or other release into the environment should be employed only as a last resort and should be conducted in an environmentally safe manner."