Over the past 30 years, numerous research studies have reported on the effect of air pollution on respiratory health. According to the Environmental Protection Agency (EPA), two key air contaminants can trigger asthma attacks and exacerbate asthma symptoms: ground level ozone and particle pollution. Ground level ozone, a gaseous product formed when certain pollutants combine in the presence of sunlight, can irritate the respiratory airways and cause coughing, wheezing, and shortness of breath. Particle pollution includes any particle suspended in the air, such as dirt, dust, and soot. Small particles with a diameter less than 2.5 micrometers are particularly concerning, as their size allows them to enter deep into the airways of the respiratory tract, cause irritation, and exacerbate asthma symptoms.