“Air toxics” is defined as “air pollution,” where pollution is an “undesirable state of the natural environment being contaminated with harmful substances as a consequence of human activities.” In addition, the EPA (2012, July 16) says pollutants include compounds that are known or suspected to cause serious health effects, which may include, but are not limited to, cancer, reproductive effects, or birth defects, and/or to cause harmful environmental effects. The pollutants may come from natural sources (such as radon gas rising from the ground) or from man-made sources (such as chemical compounds emitted by factory smokestacks or benzene fumes given off when pumping gas).
People are exposed to toxic air pollutants in many ways that can pose health risks, such as by breathing in contaminated air; eating contaminated food products (i.e. fish from contaminated water; meat, milk, or eggs from animals that fed on contaminated plants; and fruits and vegetables grown in contaminated soil); drinking water contaminated by toxic air pollutants; eating contaminated soil (most often found in children who ingest contaminated soil from their hands or objects they place in their mouths); or touching contaminated soil, dust, or water (EPA, 2011; 2012, Oct. 5).
Once air toxics enter the body, they accumulate in certain body tissues. Predators often collect greater pollutant concentrations than their prey, since above their own levels of toxic exposure, they ingest animals that already have high concentrations of the toxin stored in their tissues. This process is called biomagnification. The result is toxics concentrations much higher than those in the surrounding water, air, or soil (EPA, 2011).
Hahn, Payne, & Lucas (2010) list five classes of materials that fall under the heading of air toxics: lead, volatile organic compounds (VOCs), biological pollutants, tobacco smoke, and asbestos. In addition to these, the Environmental Protection Agency (EPA) includes ozone, mercury, radon, and particulate matter under this broad category (EPA, 2012, Oct. 5). We will discuss several of these materials below.
Lead is a toxic metal found naturally in the environment as well as in manufactured products. It has serious health effects when ingested or inhaled, especially for children. It can delay development, lower IQ, reduce attention span, and increase behavioral problems. And since lead is not readily excreted by the body, it will accumulate in the body’s tissues over time (Hahn, et. al, 2010). Until 1980, the major sources of lead emissions were car and truck fuel, as well as house paint and plumbing solder. The EPA imposed regulations to remove lead from gasoline, and emissions from fuel declined significantly – by 95 percent – between 1980 and 1999 (EPA, 2012, July 16). Yet in late 1991, more than 10 years after the EPA banned lead-based paint, the secretary of the U.S. Department of Health and Human Services called lead “[still] the number one environmental threat to the health of children in the United States” (Hahn, et. al, 2010).
Volatile organic compounds (VOCs) are carbon-containing gases emitted into indoor air from a wide range of household products, such as varnish and paint thinner. One very common VOC is formaldehyde, a preservative that is also used in and emitted by many building products, such as plywood, particleboard, fiberboard, urea foam insulation, and building/carpet adhesives (Hahn, et. al, 2010); this volatility and release of gas is what causes the “new product” smell. The health effects of VOCs vary depending on which specific substance is involved. These health effects can include damage to the immune system, as well as neurological, reproductive (e.g., reduced fertility), developmental, and respiratory problems (EPA, 2011).
According to the American Cancer Society in 2004 (as cited in EPA, 2012, July 16), tobacco smoke is the leading cause of lung cancer, causing an estimated 160,000 deaths in the U.S. every year. The link between the two was first publicized on January 11, 1964, by Dr. Luther L. Terry, who was the U.S. Surgeon General at the time, and lung cancer now surpasses breast cancer as the number one cause of death among women. In addition, a smoker who is also exposed to radon (another air toxic) has a much higher risk of developing lung cancer.
Secondhand tobacco smoke is the third leading cause of lung cancer (after radon), and it is responsible for an estimated 3,000 lung cancer deaths every year (EPA, 2012, July 16). Exposure to secondhand smoke can have serious consequences, especially for children’s health, including asthma, bronchitis, pneumonia, and even ear infections.
Asbestos is a naturally occurring mineral fiber found in rocks and soil that is commonly used in a variety of building construction materials because of its insulating and fire-retardant properties. When asbestos-containing materials are damaged or disturbed by repair, remodeling, or demolition activities, the microscopic fibers become airborne and can be inhaled into the lungs, where they can cause significant health problems. According to the EPA (2012, July 16), three of the major health effects associated with asbestos exposure include lung scarring, lung cancer, and mesothelioma, a rare cancer of the heart, lung, and chest lining.
The Environmental Protection Agency is tasked with the monitoring and regulation of air toxics, and, since 1970, the Clean Air Act has provided the primary framework for protecting people and the environment from the harmful effects of air toxics (EPA, 2011). A key component of this Act is a requirement that the U.S. EPA significantly reduce "routine" emissions of the most potent air pollutants – those that are known or suspected to cause serious health problems, such as cancer or birth defects.
According to the EPA (2011), “A key component of future efforts to reduce air toxics is the Integrated Urban Air Toxics Strategy released by EPA in July 1999. The Strategy presents a framework to address air toxics in urban areas and builds on the substantial emission reductions already achieved from cars, trucks, fuels, and industries such as chemical plants and oil refineries. The Strategy outlines actions to further reduce emissions of air toxics and to improve EPA's understanding of the health risks posed by air toxics in urban areas.”
Individuals can also take steps toward reducing their exposure to air toxics, including not smoking, making sure all building materials in their homes and schools are formaldehyde- and asbestos-free, reducing gasoline consumption, and checking their homes for radon. In addition, they need to pressure elected officials to mandate reductions in toxic substances. Air toxics is a pervasive problem, but with a little effort, we can achieve a substantial reduction in the prevalence of these hazardous compounds, as well as their harmful effects on people and the environment.
Air and Radiation. (2012, July 16). Environmental Protection Agency. Retrieved from http://www.epa.gov/air/index.html
Air Toxics. (2012, October 5). Environmental Protection Agency. Retrieved from http://www.epa.gov/oar/toxicair/newtoxics.html
Hahn, D. B., Payne, W.A. & Lucas, E.B. (2010). The Environment and your Health. In Focus on Health (10th ed.), (407-432). New York, NY: McGraw-Hill.
Taking Toxics Out of the Air. (2011). Environmental Protection Agency. Retrieved from http://www.epa.gov/air/toxicair/takingtoxics/p1.html#2
WordNet 3.0. (2012). Farlex, Inc. Retrieved from http://www.thefreedictionary.com/Air+toxics