What is Air Pollution?
Air is considered polluted when it threatens the health of human beings and other living things.
Air pollution is one of the greatest threats to human health and environmental quality in the United States. Some of the effects of air pollution range from pulmonary diseases, cancers and eye irritations to crop damage, acidic lakes and streams, and soot covered buildings and heavily eroded structures. In Areas with particularly poor air quality there are increased costs due to high medical bills and decreased property values. Many Americans live in areas where the air does not meet quality standards and do not even realize it.
| According to the U.S EPA, more than one out of every four children live in areas that do not meet national air quality standards. |
Air pollution is everywhere, indoors and outside, and is almost always invisible. The six most common pollutants are:
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They are commonly known as the "criteria" pollutants because the EPA has set national ambient (outside) air quality standards for each one under the Clean Air Act.
The first five pollutants are considered primary pollutants because they are released directly into the air. Ozone is considered a secondary pollutant because it is formed when nitrogen oxides and hydrocarbons in the air combine in the presence of sunlight into a dangerous mixture.
Other pollutants include:
Toxic Metals:
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Toxic Organics:
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Others:
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The heavier pollutants, such as metals, mostly drop to the Earth near their source. Lead, for example, was found in high concentrations along most busy roadways in the 1980s when it was a common gasoline additive. Plants and trees help filter out some of the air pollutants by collecting heavier particles in their leaves.
The Lighter pollutants, such as sulfur dioxide and nitrogen oxides, are carried by the wind great distances and can affect communities hundreds of miles from the source.For a more complete list and description of air pollutiants go here
There are many sources of air pollution.
Two general sources are stationary sources and mobile sources.
| Stationary sources typically refer to smokestacks found on factories, electrical generation plants and chemical plants. | Mobile sources refer to automobile, truck and bus and other vehicular emissions. |
Some other, not so obvious, common sources include
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Air pollution has been around a lot longer than humans. Some naturally occurring pollutants come from volcanic eruptions and natural forest fires ignited by lightning strikes. Particles from the surface of oceans and land can be swept up into the air by strong winds; and some pollution in our atmosphere is the result of the natural process of organic decay. Since many of these events are less frequent and not as widespread, the atmosphere is generally able to recover quickly from these small doses of pollution.
It is the air pollution caused by human activities, however,that may threaten our environment and our health on a daily basis.
| Asthma deaths in children and young adults increased by 118 percent from 1980 to 1993, many of them caused directly or indirectly by air pollutants. |
Air Pollution History Highlights
| 1880s | The first air pollution laws were passed by Chicago and Cincinnati, and were soon followed by New York and Pittsburgh. |
| 1890s | Ohio became the first state to pass a law to regulate the emissions from steam boilers. |
| 1948 | In Donora, Pa. and again in 1952 in London, toxic fogs killed dozens of people and made thousands ill. |
| 1963 | Congress passed the first Clean Air Act to study the effects of air pollution and provide grants and training to local agencies to help control it. |
| 1966 | 80 people died in New York City from air pollution-related causes resulting from a four-day atmospheric inversion. |
| 1970 | The Clean Air Act was strengthened and made the U.S. EPA responsible for the federal effort to control air pollution. |
| 1988 | An EPA study found that indoor air can be 100 times as polluted as outdoor air. |
| 1990 | Clean Air Act amendments include requirements to control the emission of sulfur dioxide and nitrous oxides into the air. |
The Clean Air Act
| Why Clear Skies? |
| Air quality has improved, but serious concerns persist– Pennsylvania’s citizens suffer ill effects from air pollution, including asthma attacks and prematuredeath |
| Electricity generation sector remains a major emissions source– Very cost-effective to control the power sector, relative to other sources– Sources are concerned about upcoming complex and burdensome regulations |
The Clean Air Act (CAA) of 1970 was the first major environmental law through which the federal government set national, enforceable air quality standards. The CAA has reduced air pollution significantly, especially emissions of lead, particulates, sulfur oxides and carbon monoxide.
It functions by setting national ambient air quality standards for the six criteria pollutants through mobile and stationary sources, and for toxic and hazardous pollutants.
The Act also specifies the type of technology sources must use such as ‘best available control technology” or “lowest achievable emission rate.” When an area exceeds the minimum federal air quality standards set for each of the criteria pollutants, it is said to be in non- attainment An area can also be listed as near non- attainment if it is close to violating these standards.In 1990, the Clean Air Act was amended. The goal of these amendments is to reduce the level of air pollution by 56 billion pounds a year. This is approximately 224 pounds for every man, woman, and child when the law is fully phased in by the year 2005. The CAA also enables the EPA to penalize a company for violating the Act.
Although the CAA provides the necessary framework to protect outdoor ambient air, indoor air quality is not addressed under the Act. Private policy and behavioral changes need to be implemented in order to address this pollution problem. The Clean Air Act has been into our atmosphere, but more and better approaches need to be taken.
Current assessments of pollutants are done on a chemical-by-chemical basis instead of also taking into account the cumulative or additive affects of the chemicals combined at once or over time. The special needs of at-risk children and their environments must also be researched and addressed. Whether public or private, the key to the success of a policy relies on proper enforcement and public involvement.
Restrictions
In many large cities, automobile restrictions are enforced to help reduce the levels of emissions. High Occupancy Vehicle (HOV) lanes are designated on heavily traveled roadways in order to encourage car- pooling. In many of these same areas, Inspection and Maintenance (I&M) programs are mandatory during annual routine inspections. These tests include measurements of exhaust emissions and they ensure that motor vehicles conform to emissions standards based on the make, model and year of the vehicle. Other types of restrictions may include a ban on backyard burning practices or smoking restrictions in public buildings and work sites.
Education
Many harmful exposures can be eliminated or reduced associated with air pollutants. Some of the current air quality programs address the potential for higher rates of asthma and lung diseases. These educational efforts typically focus on populations living in poverty and racial minorities living in areas where air quality is affected by local industries. More programs are being developed that bring attention to the idea that everyone contributes to air pollution~ and. therefore, everyone can help to reduce it.
The U. S. government has made information about toxic pollutants and their sources more accessible through the Emergency Planning and Community Right-to- Know Act to help educate and inform the general public. The government has also set up over 5.000 air monitors across the country to measure the criteria pollutants in our air. This information is used by meteorologists and released to the public as Air Quality Indexes (AQI) or Pollution Standard Indexes (PSI) during many daily weather reports.
| Federal Laws | State Laws |
There are a series of federal and state laws regarding air quality that are designed to work together to provide the framework needed protect our health and the health of our environment Some of these laws directly affect our natural resources, while others dictate how people. businesses and government should act.
Federal Laws
Clean Air Act (CAA)* - The CAA restricts the kinds and amounts of pollutants that may be released into the air by cars, industry, and other sources. The CAA requires states to control air pollution through the use of permits. All air pollution sources must meet emissions limits set by state plans. These plans describe the pollution control and permit requirements for new emission sources. The National Ambient Air Quality Standards (NAAQSs) are the basis of the CAA program and cover air emission standards for sulfur dioxide, nitrogen oxides, particulate matter, carbon monoxide, ozone, and lead. For each, there is a primary standard that protectshuman health with an adequate safety cushion, and a secondary, more stringent, standard that better promotes public welfare.
1977
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1990
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Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund)** - CERCLA provides a federal "super fund" to clean up uncontrolled or abandoned hazardous waste sites, as well as. accidents, spills, and other emergency releases of pollutants and contaminants into the environment. Through the Act, EPA was given power to seek out those parties responsible for any release and assure their cooperation in the cleanup. Superfund site identification, monitoring, and response activities in states are coordinated through the state environmental protection or waste management agencies.
Emergency Planning and Community Right-to-Know Act (EPCRA)* - Also known as SARA Title III. EPCRA makes sure people have an opportunity to find out what chemical hazards are in a community, and helps communities plan for chemical accidents or incidents. EPCRA requires states to develop plans to prepare for possible chemical accidents or emergencies. It also makes businesses report annually on the chemicals they use and store and the amount of toxic chemicals they have released into the environment. This information is available to the public.
Toxic Release Inventory - Established by the 1986 EPCRA, industries are required under this act to report annual releases of 330 chemicals to the EPA. These figures are then made available to the public. Citizens can sue polluters if they fail to report their toxic releases, and if found guilty, can be fined up to $25,000 per chemical, per day. The TRI is, however, limited it only covers large facilities in the manufacturing sector; requires that companies provide estimates of toxic emissions, not actual amounts; that the TRI only reports on the emissions, not the health risks~ and companies can ship chemicals for off-site recycling or reuse without having to report emissions resulting from these transfers. (The TRJ data is two years old at the time it is published. Even though this TRJ data is not the most current, it should provide a good starting point by listing the most recent flicilities in non-attainment. Each faclity can provide the current TRI data that can then he compared to the published TRJ data to show any increase or decrease in emissions over the past Iwo years. )
Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)** - The primary focus of FIFRA was to provide federal control of pesticide distribution, sale, and use. EPA was given authority under FJ.FRA not only to study the consequences of pesticide usage but also to require users (farmers, utility companies, and others) to register when purchasing pesticides. Through later amendments to the law, users also must take exams for certification as applicators of pesticides. All pesticides used in the United States must be registered (licensed) by EPA. Registration assures that pesticides will be properly labeled and that, if used in accordance with specifications. will not cause unreasonable harm to the environment.
Occupational Safety and Health Act (OSHA)* - OSHA sets minimum health and safety standards for the workplace. Private employers must protect their employees by following OSHA requirements
Pollution Prevention Act ** - The Pollution Prevention Act focused industry, government, and public attention on reducing the amount of pollution produced through cost-effective changes in production. operation, and raw materials use. Opportunities for source reduction are often not realized because existing regulations, and the industrial resources required for compliance, focus on treatment and disposal. Source reduction is fundamentally different and more desirable than waste management or pollution control. Pollution prevention also includes other practices that increase efficiency in the use of energy, water, or other natural resources, and protect our resource base through conservation. Practices include recycling, source reduction, and sustainable agricuhure
Resource Conservation and Recovery Act (RCRA)* - RCRA controls hazardous waste management from generation through disposal, including the waste generators, transporters, and owners and operators of waste treatment, storage, and disposal facilities. Requirements are enforced through permits that specify the practices and conditions that must be followed by hazardous waste handlers. RCRA applies mainly to tracking and ensuring safe management of hazardous waste from creation to disposal. RCRA works together with Superfund, which addresses the serious problem of abandoned wastes and inactive hazardous waste facilities. Superfund handles the mistakes of the past, and RCRA tries to prevent the creation of new hazardous sites.
Superfund Amendments and Reauthorization Act (SARA)** - SARA of 1986 reauthorized CERCLA to continue cleanup activities around the country Several site-specific amendments, definitions, clarifications, and technical requirements were added to the legislation, including additional enforcement authorities. Title III of SARA also authorized the Emergency Planning and Community Right-to-Know Act (EPCRA).
Toxic Substances Control Act (TSCA)** - TSCA of 1976 was enacted by Congress to test, rec~ulate, and screen all chemicals produced or imported by the United States. Many thousands of chemicals and their compounds are developed each year with unknown toxic or dangerous characteristics. To prevent tragic consequences, TSCA requires that any chemical that reaches the consumer market place be tested for possible toxic effects prior to commercial manufacture. Any existing chemical that poses health and environmental hazards is tracked and reported under TSCA. Procedures also are authorized for corrective action under TSCA in cases of cleanup of toxic materials contamination. TSCA supplements other federal statutes, including the Clean Air Act and the Toxic Release Inventory under EPCRA.
Freedom of Information Act (FOLA)** - FQJA provides specifically that "any person" can make requests for government information. Citizens who make requests are not required to identify themselves or explain why they want the information they have requested. All branches of the federal government must adhere to provisions of FOIA with certain restrictions for work in progress (early drafts), enforcement confidential information, classified documents, and national security information.
National Environmental Policy Act (NEPA)** - NEPA was one of the first laws ever written that establishes the broad national framework for protecting our environment. NEPA's basic policy is to assure that all branches of government give proper consideration to the environment prior to undertaking any major federal action that significantly affects the environment. NEPA requirements are invoked when airports, buildings, military complexes, highways, parkland purchases, and other such federal activities are proposed. Environmental Assessments and Environmental impact Statements, which are assessments of the likelihood of impacts from alternative courses of actiow are required from all federal agencies and are most visible NEPA requirements.
Small Business Regulatory Enforcement Fairness Act - The act requires that federal agencies imposing pollution restrictions or standards need to consult with community groups and businesses before making their proposals. The proposed regulations must take into consideration the financial impact to small businesses. Under this Fairness Act, agencies must show that they have complied with procedures and have considered the impacts, it does not require that agencies make regulations less burdensome. Congress may review these proposed regulations and, with the president's signature, block their implementation if found unfair or if they did not show reasonable small business impact assessments
*Source: U.S. EPA HAZ-ED Classroom Activties for Understanding Hazardous Waste (EPA540-K-95-005), April 1996.
**Source: U.S. EPA, Guide to Environmental Issues (EPA520B--94-001), September 1996.
Once the National Ambient Air Quality Standards (NAAQSs) have been set for specific pollutants by the EPA, each state must design a State Implementation Plan (SIP) which requires that their sources will eventually meet the Clean Air Act standard. If a state fails to produce or implement an adequate SIP, the EPA is directed by the CAA to impose sanctions such as withholding federal highway funds.
There are numerous state laws that also address air quality issues. To get a listing of these laws for your state, contact your State Health Departments and Departments of Environmental Protection.
In some regions, gas-powered yard tools are a major source of air pollution. Their small engines, with no pollution controls, emit VOCs, benzene, nitrogen oxides and carbon monoxide.
Below are EPA estimates of the air pollution produced from using gas-powered yard too is as compared to the pollution produced from driving a car.
| One hour's use | Pollution from a car trip of this many miles |
| Garden tractor | 30 |
| Shredder | 30 |
| Power mower (push) | 50 |
| Trimmer | 70 |
| Leaf blower | 100 |
| Chain saw | 200 |
Although air pollution continues to be a problem, substantial improvements have been made over the last 20 years. Better industrial processing techniques, improved car maintenance programs and enforcement of laws addressing air pollution together have made the following improvements in air quality.
- Ozone levels decreased 13% between 1979 and 1986 due to the Federal Motor Vehicle Control Program and stationary source control efforts.
- Nitrogen oxide levels tripled between 1940 and 1970. But despite the fact that fossil fuel consumption increased substantially after 1970, nitrogen oxide levels only increased 7% between 1970 and 1986.
- There was a 23% decrease in ambient particulate levels from 1977 to 1986 due to EPA emissions standards, improved paving and street cleaning techniques, and bans on backyard and agricultural burning.
- Our greatest success in reducing air pollution has been the reduction of lead emissions by 99% between 1970 and 1990 due to EPA's ban on leaded fuels.
- Attempts have been made to reduce the amount of stratospheric ozone depleters by prohibiting individuals that maintain, service, repair or dispose of air conditioners from knowingly venting refrigerant into the atmosphere. They are required to have recovery capture equipment to ensure proper handling and disposal of the coolants.
- Carbon monoxide emissions have decreased 50% between 1970 and 1990 due to reductions required by the Federal Motor Vehicle Control Program.
- Alternative vehicle fuels called "clean fuels" are being developed and tested to decrease our dependency on imported oil and our use of fossil fuels. These clean fuels produce less carbon dioxide are less reactive and less toxic. They include alcohols, electricity, natural gas, and propane.
- In many areas across the country, small gas-powered engines (lawn mowers, chain saws. etc.) are required to meet emissions standards. Many of these devices now run on cleaner fuels or have been redesigned to be more efficient.
Source: EPA August 1988, EPA October 1992, EPA April 1994, EPA August 1996
| FEDERAL AGENCIES | STATE AGENCIES | OTHER ORGANIZATIONS |
FEDERAL AGENCIES
The Environmental Protection Agency has information related to all types of environmental problems from clean air to hazardous waste. To receive free brochures and information on how to become active with saving the environment call (202) 260-2090: or search their website at http://www.epa.gov to find a list of documents related to facts about the environment and the environmental safety of schools. Click on the students/teachers icon to access this information.
EPA Region III Office (http://www.epa.gov/region3/)
(DE, DC, MD, PA, VA, WV)
Air, Radiation and Toxic Division
814 Chestnut Street
Philadelphia, PA 19107
(215) 566-2100
STATE AGENCIES
Pennsylvania Department of Environmental Protection Bureau of Air Quality http://www.dep.state.pa.us/dep/deputate/airwaste/aq/aqhome.htm
400 Market Street, 12th Floor
Harrisburg, PA 17105
(717)787-9702
New York Department of Conservation
Division of Air Resources http://www.dec.state.ny.us/website/dar/index.html
50 Wolf Road, Room 190
Albany, NY 12233-3250
(518)457-7230
Ohio Environmental Protection Agency
Division of Air Pollution Control http://www.epa.state.oh.us/dapc/
P.O. Box 1049
Columbus, OH 43216-1049
(614)644-2270
OTHER AGENCIES AND ORGANIZATIONS
The American Lung Association is a great resource for finding information about air pollution. Topics include ozone depletion, exercise and breathing, and much more For more information call
1-800-LUNG-USA to contact your local American Lung Association chapter or contact their website at http://www.lungusa.org.
The Environmental Health Clearinghouse has available information to the public on air pollution and health, toxic air, and the affects of pollution on children, everything you ever wanted to know about the problems of the environment. For more information and free brochures call Environmental Health at 1-800-643-4784 or explore their website athttp://www.infoventures.com
Air and Waste Management, inc. has expert information on environmental issues on air pollution, recycling and much more. To find information on important environmental topics click on publications and enter a topic under search. Air and Waste Management also offers links to other environmental sites. To order activity materials and receive free brochures call (412) 232-3444 or explore their website at http://www.awma.org.
Sierra Club is devoted to protection of the earth's ecosystem and natural environment. To find information on the latest environmental topics like air pollution, call (415) 977-5500 or explore their website at http://www.sierraclub.org. Click on search and enter the topic you want informationon. The Sierra Club also has a list of activist guides, and picture books to read and help you better understand the importance of the environment.
National Association of Physicians for Environment has information on how air pollution affects the body and organs in the body. For more information to receive free brochures and information about videos contact their website at http://www.cehn.org/cehn/resourceguide/nape.html
E: The Environmental Magazine, the only independent, environmental magazine in the U.S., has great information on some of the hottest environmental issues like air pollution, health problems, air quality, and consumer products. For more information on how you can subscribe to learn about these issues and receive information call (815) 734-1242 or explore their website at http://www.emagazine.com
| FEDERAL AGENCIES | STATE AGENCIES | OTHER ORGANIZATIONS |
| Outdoor Air Pollution Summary | Indoor Air Pollution Summary |
There are two kinds of ozone in our atmosphere
Stratospheric ozoneThe is naturally occurring and exists high above our troposphere in the layer called the stratosphere. Stratospheric ozone is highly desirable because it shields us from harmful ultra- violet rays that can cause skin cancers. |
Ground level ozoneThis type is not as desirable. This colorless pollutant is a highly reactive, unstable form of oxygen. It is produced in the atmosphere through a series of photochemical reactions that involve volatile organic compounds (VOCs), nitrogen oxides and sunlight; and in high concentrations it has a pungent odor. Ground level ozone is the principle constituent of smog at the Earth 's surface. |
Sources
VOCs are generated by motor vehicles, petroleum refineries, chemical manufacturing facilitits, dry cleaners, gasoline stations, house paints, industrial solvents and print shops. The nitrogen oxides are byproducts of the combustion of fossil fuels and are emitted by utilities, motor vehicles and industrial facilities.
Effects
Ground level ozone causes significant health and environmental problems. Because of its highly reactive nature, it tends to break down biological tissues and cells it comes into contact with especially through breathing. Once inside the respiratory tract, it can cause intense irritation, chest pains, coughing, lung inflammation. susceptibility to lung infections and produce impaired lung function such as inability to take deep breaths.
Exposure to ozone can also aggravate pre-existing asthma conditions. Ozone is the most harmful pollutant to plant life and causes reduced yields in agricultural crops and injures forests and other vegetation by stunting its growth. Ozone exposure can also damage textiles, cause discoloration of dyes, and accelerate the disintegration of rubber products.
Carbon monoxide is an odorless, colorless gas that is emitted from motor vehicles and engines that have incomplete fuel combustion. Carbon monoxide "hot spots" are areas with heavily congested roadways and intersections. Although carbon monoxide levels have declined in most parts of the country since the early 1970s, the standards set by the EPA are still exceeded in over 142 cities and counties in the U.S.
National ambient levels of carbon dioxide fell 320 %between 1977 and 1986 largely due to automobileemissions controls. Further reductions in many places will depend on local "inspection and maintenance" (I&M) programs that make sure the control equipment is functioning properly. These I&M programs are currently in over 60 urban areas in 32 states.
Sources
The major source of carbon monoxide is motor vehicles, especially when they are burning fuel inefficiently. This poor fuel combustion generally occurs when engines are first started in the morning or when a motor vehicle is idling or moving slowly in congested traffic. High concentrations of carbon monoxide can be found in confined spaces such as parking garages and tunnels with inadequate ventilation. Other sources include incinerators and wood stoves.
Community InitiativeThe citizens of San Antonio, TX, have joined the fight against unnecessary car emissions. Through the Smoking Vehicle Program. citizens are able to call and report the license plate number of a "smoking vehicle" to the state. The state then mails a letter to the car owner, which suggests car repairs in order to control the unnecessary emissions. |
Effects
When carbon monoxide is inhaled, it replaces oxygen in the bloodstream and reduces ability of blood to carry oxygen to vital organs. The cardiovascular and nervous systems are most affected by this carbon monoxide poisoning. Inhalation of high concentrations can impair vision, alertness, and other mental and physical capabilities by causing dizziness, headaches and fatigue. Carbon monoxide exposure adversely affects individuals with pre-existing heart disease.
Prolonged exposure can eventually cause death due to lack of oxygen in the blood.
This odorless gas is also one of the regulated outdoor air pollutants, but like nitrogen dioxide, it can be found at dangerous concentrations indoors. Recent studies show that many homes have been found to contain levels of carbon monoxide that exceed the health standard set under the Clean Air Act by the EPA.
| In many office buildings, afternoon levels of carbon monoxide can be 10 to 20 times greater than the EPA's daily standard for outdoor air qualitv. |
Sources
Carbon monoxide indoors is emitted from the same sources as nitrogen dioxide as well as many others. These other sources include: tobacco smoke, gasoline engines running in attached garages, unvented kerosene heaters, and charcoal (which should never be used indoors).
Effects
Carbon monoxide replaces oxygen in the blood stream and reduces the distribution of oxygen to vital organs. If inhaled in high amounts, carbon monoxide can cause headaches, fatigue, confusion, nausea, dizziness, and lack of coordination. The exposure can also intensify pre-existing cardiovascular problems and can lead to death by suffocation.
Outdoor Nitrogen Dioxide (NO2)
Nitrogen dioxide appears as a brown haze at high concentrations. It is produced when fuel is burned at high temperatures and reacts with the natural nitrogen in the atmosphere. It is a major contributor to acid precipitation and smog.
Sources
Cars, buses, trucks and airplanes emit over half of the nitrogen dioxide found in our atmosphere. It is also the result of burning fuels in utilities and industrial boilers.
Effects
For asthmatics, it can cause increased breathing difficulty. Individuals with weakened immunities, such as the elderly or very young, may develop respiratory illnesses such as chest colds and coughing with phlegm.
Indoor Nitrogen Dioxide (N02)
Although nitrogen dioxide is listed as one of the major outdoor air pollutants, it is also a potential danger indoors as well. A recent study found that concentrations of nitrogen dioxide indoors can be five times greater than the levels found outside.
Sources
Gas appliances such as ranges, water heaters, clothes dryers, etc., fireplaces, and wood and coal stoves can emit high levels of nitrogen dioxide if not properly maintained and ventilated.
Effects
Nitrogen dioxide exposure can irritate the eyes and respiratory tract and lower a person s resistance to respiratory infections. Prolonged exposure can lead to chronic bronchitis and respiratory tissue damage.
Particulates are minuscule particles of dust, metal, vapors and other materials that float in air; and are commonly found in soot and smoke. Particulate size is measured in microns (one micron is about 1/25,000th of an inch), and pose the most serious health threats because they tend to become lodged in lung tissues and remain in the body for a long time.
Sources
The major sources of particulates include industrial processes, smelters, steel mills, power plants, cotton gins, cement plants, diesel engines, and agricultural ground breaking and burning practices. Wood stoves and fireplaces are also significant sources for particulates in the air. Wind-blown dust from roads, parking lots and construction sites also contributes to particulate pollution in urban areas.
Effects
The health effects from particulates range from eye and throat irritations to infections, to causing chronic respiratory diseases, lung damage and possibly death. Some particulates that are emitted from diesel engines are suspected of causing cancer. Others, such as wind-blown dust, can contain other harmful substances such as pesticides and PCBs (polychlorinated biphenyls). Particulates can also corrode building materials, soil clothing, damage vegetation and severely reduce visibility.
Biological Pollutants and Microorganisms
Biological pollutants such as pollen, dust mites and pet dander, and microorganisms such as bacteria, fungi, viruses and molds are present in air almost everywhere but high concentrations, especially indoors, can effect human health.
Sources
Heating ducts and ventilation systems can become havens for microorganisms when they are not properly cleaned and maintained. Other areas particularly susceptible to microorganism build-up are washrooms, wall and ceiling spaces, humidifiers and dehumidifiers, planters and carpets. In most homes, the major sources of allergens are listed as dust mites, pet dander (mostly dogs and cats) and cockroaches. Wall-to-wall carpeting in homes, schools and businesses act like reservoirs of dust mites and microorganisms. Vacuuming carpets only disperses and suspends these particles in the air.
Effects
The most common health effects from microorganisms and biological pollutants are allergic diseases such as allergic rhinitis and skin diseases. More serious effects include asthmatic problems and bacterial and viral infections. Some common contagious diseases caused by some microorganisms are influenza and Legionnaires' disease. Individuals with particularly sensitive immune systems are generally the most affected by microorganisms and other biological pollutants. Studies have shown that these biological pollutants are thought to be responsible for most of the acute cases of asthma in adults under the age of 50.
Outdoor Sulfur Dioxide (S02)
Sulfur dioxide is a colorless, odorless gas at low concentrations but pungent at very high concentrations. It can be transported great distances in the atmosphere because it binds with particles of dust, smoke and aerosols. Sulfur dioxide also combines with water vapor to form sulfuric acid, a major cause of acid rain.
Sources
Sources of sulfur dioxide emissions include industrial emissions, institutional and home furnaces and boilers, petroleum refineries, paper mills and chemical plants. Home furnaces and coal-burning stoves are sources that often most directly affect neighborhoods.
| Over 800% of the sulfur dioxide emissions in the U.S. originate in the 31 states east of or bordering the Mississippi. Most emissions come from power plants or factories burning high-sulfur coal located in states which are in or adjacent to the Ohio River Valley. |
Effects
Both sulfur dioxide and nitrogen dioxide combine with water vapor to form acid rain which lowers the pH levels in streams and ponds to adversely affect wildlife. Sulfur dioxide is also a major constituent of smog which can harm vegetation and impair visibility in areas with high concentrations. It can be very harmful to individuals with pre-existing respiratory problems such as asthma.
Formaldehyde vapors are released indoors from resins and treatments used in over 3,000 different building products It is also used in a water solution as a preservative and disinfectant.
Sources
Several products within homes can contain formaldehyde The most common sources are: foam insulation; resins in particleboards; plywood paneling; fiberboard; and some carpets, drapery and upholstery fabrics. Mobile homes typically contain high levels of formaldehyde due to the extensive use of these products and the airtight construction.
Effects
The most common health effects from formaldehyde exposure are headaches, dizziness, lethargy, rashes, nausea, and irritation of the upper respiratory tract and eyes. Individuals with weakened immune systems, children and the elderly are most affected by formaldehyde emissions. The EPA has listed formaldehyde as a known human carcinogen because prolonged exposure may result in cancer.
In the past, lead was added to almost all gasoline to improve engine performance. Laws restrict the manufacture and use of leaded gasoline because lead particles escaped through the exhaust pipe and polluted the air while the engine was running. New cars no longer require leaded fuels. These lead particles typically fall to the ground along roadsides and heavily traveled areas; and can adversely affect human health through direct inhalation or ingestion of lead-containing soils and dust. This is particularly true for young children, whose normal hand-to-mouth activities pose a greater threat of lead ingestion.
Sources
Most airborne lead comes from the leaded fuels still used for aviation purposes. Other sources include coal combustion, smelters, car battery plants, and burning of garbage containing lead products.
Effects
Elevated levels of lead in the body can adversely affect mental development and cause abnormalities in kidney function and blood chemistry. Young children are at a greater risk due to higher chance of ingestion and the sensitivity of young organs and tissues to lead poisoning.
This metal is a serious outdoor air pollutant, but it may also be extremely hazardous if it is detected inside the home. It is commonly found in the paints (lead-based paint) of homes and apartment buildings built before the late 1970s and in various other household items. The federal government banned the use of lead-based paints in housing in 1978 however other sources are just as common. infants and children commonly ingest lead by eating paint chips or soils with their mouths or by breathing in lead dust.
| One out of every eleven children in the United States has dangerous levels of lead in their their blood streams. Lead can even affect babies before they are born. |