Under the maintenance plan, a ground-level ozone violation would trigger a contingency plan for sources to reduce emissions, but EPA has the flexibility to decide whether the plan should be reexamined and adjusted or whether the area should be designated nonattainment. Most specific controls on emissions would be directed under a locally-adopted maintenance plan rather than federal requirements. The public would not be exposed to excessive concentrations of ozone. Ozone can cause health effects, including irritation of the lungs, nose and throat. It can worsen existing conditions of such diseases as asthma, bronchitis and emphysema.
Ozone also impedes timber and crop growth.