September 8, 2011, San
Francisco, CA – With the continuing goal of improving air quality for millions
of Californians, the U.S. Environmental Protection Agency is proposing to
approve the eight-hour ozone air quality plans for the San Joaquin Valley and
South Coast areas. These plans, known as State Implementation Plans, are
the road maps to meeting the Clean Air Act standard of 0.08 parts per million of
ozone as measured in eight-hour increments.
September 8, 2011, San
Francisco, CA – With the continuing goal of improving air quality for millions
of Californians, the U.S. Environmental Protection Agency is proposing to
approve the eight-hour ozone air quality plans for the San Joaquin Valley and
South Coast areas. These plans, known as State Implementation Plans, are
the road maps to meeting the Clean Air Act standard of 0.08 parts per million of
ozone as measured in eight-hour increments.
The air districts are
making steady progress toward meeting the eight-hour ozone standard, one of the
National Ambient Air Quality Standards, by 2024. In 1997, the EPA first
established the eight-hour ozone standard, which replaced the older one-hour
ozone standard (0.12 ppm). The eight-hour standard is more protective of human
health because it addresses the impacts of exposure over longer periods of
time.
The EPA is proposing to
approve the eight-hour ozone air quality plans for the San Joaquin Valley and
South Coast, which include their attainment demonstrations, enforceable
commitments and reductions from new technologies.
There have been vast
improvements in air quality in California over the previous decades. The worst
sites in California have demonstrated a 52 percent improvement in ozone from
1976 to 2010, a 29 percent improvement in fine particulate matter (PM2.5) from
2001 to 2010, an 84 percent improvement in carbon monoxide from 1970 to
2009, and a 92 percent improvement in sulfur dioxide from 1970 to 2009.
In both areas, statewide
measures such as the in-use truck and off-road diesel rules, and smog-check
improvements will further reduce air pollution. In the San Joaquin Valley,
district rules will reduce pollution from open burning, boilers, composting, and
livestock operations. In the South Coast, the marine vessel rules and district
rules targeting pollution from solvents, lubricants and boilers will reduce
ozone pollution.
Ground-level ozone is
formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react
in the atmosphere in the presence of sunlight. NOx and VOCs are called ozone
precursors. Motor vehicle exhaust, industrial emissions, and chemical solvents
are the major sources of these chemicals. Ozone pollution is a concern
especially when the weather conditions needed to form it – lots of sun and hot
temperatures – occur. Ozone pollution can irritate airways, worsen asthma
symptoms and increase hospitalizations for respiratory cases. Children and the
elderly are most impacted by ozone pollution.
The EPA is providing a
30-day public comment period on its eight-hour ozone proposed actions.
For more information, please visit: http://www.epa.gov/region9/air/actions/ca.html.
