Rhode Island's air meets federal clean air standards almost all year. During the 1999 ozone season, Rhode Island exceeded the eight-hour standard 18 times on 11 days. High ozone levels can cause coughing, chest pain and throat irritation in healthy people and can trigger asthma in sensitive individuals. In 1997 EPA issued stricter standards for ozone and fine particles. The new eight-hour ozone standard is based on studies showing health impacts from lower levels of ozone over longer periods of time.
Court challenges to the new standards are pending.
However, since adverse health effects can occur if the new standards are exceeded, DEM has committed to meeting the new ozone and fine particulate standards by 2007. Air pollution controls have reduced emissions from Rhode Island industry and utilities to the point where further improvements in this sector would come at high cost for a relatively small amount of improvement. According to EPA studies, fueling and tailpipe emissions from gasoline-powered vehicles are the largest single contributor of NOx, VOCs and air toxics . Further air quality improvements will depend heavily on measures such as controlling emissions from vehicles and their fuels. Clean air in Rhode Island will also require reducing high VOC and NOx emissions transported to Rhode Island from upwind emissions.