What is Ozone?
Ozone is an atmospheric gas that is invisible and odorless.
Ozone: Good up high, bad down low.
Up high: Ozone occurs naturally in the stratosphere, where it forms a protective layer that shields us from harmful ultraviolet rays and acts as Earth's sunscreen. This is called "good" ozone. Human activity has depleted this ozone layer and caused "holes," but due to a reduction in the use of certain chemicals, it is possiblethat the ozone layer could recover.
Down Low: Ground-level ozone is called "bad" ozone, and is the main ingredient in smog. It is also the primary pollutant of concern in southeast Florida. When emissions from motor vehicles, lawn maintenance equipment, power plants, and gas stations react with the sun, they can form ozone. Warm temperatures and low wind speeds during the summer months make summer the peak of ozone season!
Ozone in the Southeast Florida Airshed
Ozone does not recognize county boundaries. Instead, it drifts within air masses throughout our region. The U.S. Environmental Protection Agency (EPA) established a national health standard for ozone and determined that Broward, Miami-Dade, and Palm Beach counties are considered the southeast Florida airshed.
Broward County
In 1979, Broward County and the southeast Florida airshed encountered high ozone levels, and we were considered a non-attainment area for ozone. This means that we exceeded the levels for ozone that were based on national health standards established by the EPA called the National Ambient Air Quality Standards (NAAQS).
In 1990, the Clean Air Act Amendments (CAA) required automobile manufacturers to produce cleaner cars that run on cleaner fuels. The CAA also implemented programs to control ozone-forming emissions. An example of this is vapo-recovery devices at gas pumps. Due to measures such as these as well as local efforts, the aoutheast Florida airshed was reclassified in 1995 as bring in attainment for ozone!