Outdoor air quality is affected by many human and natural activities. Manufacturing companies, power plants, small businesses, automobiles, and forest fires are all sources of air pollution. Air pollution can be defined as a condition in which any foreign or natural substance is discharged into the atmosphere at levels that produce a measurableand undesirable effect on humans, animals, vegetation or materials. Any activity that releases materials into the air affects air quality. Factors that contribute to air quality include the primary emissions in the area, secondary pollutants formed in the atmosphere, pollutants transported into the area, meteorological conditions and geographical conditions. Alachua County generally enjoys good air quality with the exception of ozone (mainly in summer) and fine particulates.