In addition National Jewish has an extensive research program in asthma and expects to determine in the future the mechanisms whereby different pollutants affect the respiratory and immune systems and alter airway responsiveness. This group of susceptible individuals provides a rare opportunity for relating symptoms, medication use, and physiology to changes in air pollution. Moreover, because ventilation is increased at high altitudes, residents of Colorado may inhale an increased amount of air pollution. Denver sits in a river basin that is bordered on the west by the Continental Divide and on the north and south by lower mountain ranges. Due to its geography, the city experiences frequent temperature inversions.
Temperature inversions occur when warm air forms a cap above cool, stable air.
In Denver, these inversions trap pollutants nearer the ground, approximately level with skyscrapers. Therefore, during these frequent wintertime thermal inversions, the metropolitan area encounters elevated pollution concentrations and human exposures near the ground. Common adverse health effects of air pollution are increased irritation of the respiratory tract, chronic cough, chest tightness, decreased pulmonary function, and increased vulnerability to allergens and other immune system challenges. Individual air pollutants, such as particulate matter, are characteristically associated with various specific adverse health effects. Susceptible Populations Researchers are especially concerned about the adverse health effects of certain subpopulations.