Air Pollution's Effects on the Human Respiratory System.

The World Health Organization defines air pollution as "any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere." The most common pollutants include particulate matter, carbon monoxide, ozone, nitrogen oxide, and sulfur dioxide. The two types of air pollution, indoor and ambient, both contribute to a host of cardiac and respiratory illnesses. Exposure to excess levels of air pollution is significantly associated with a variety of acute and chronic respiratory illnesses, such as chronic obstructive pulmonary disease, asthma, respiratory allergies, and lung cancer. The effects of air pollution disproportionately impact the extremes of the age distribution, perhaps due to altered immune responses. Athletes and those who exercise outdoors are at greater risk for the respiratory effects of air pollution. This article discusses the epidemiology, types of respiratory diseases, and mechanisms involved in exposure to excess levels of air pollution. Biomedical engineering can contribute to the identification of air pollutants through the design of novel instrumentation using materials based on nanotechnology. Mathematical models can also be developed to characterize the physiological effects of air pollution.