The U.S. Environmental Protection Agency (EPA) has recently revised the Ozone standard. What does that mean for San Diego County?
What is ozone and why do we care about it?
Breathing in ground-level ozone can trigger a variety of health problems including chest pain, coughing, and throat irritation. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. Even small amounts in the air can have harmful effects.
Ozone is formed when chemicals from tailpipes and smokestacks react
with sunlight. That’s why ozone levels are at their highest during the
summer in most parts of the country. Summertime is also when people
are more active and spend more time outdoors, resulting in increased
Can ozone be both good and bad?
Ozone can have good or bad effects, depending on where it's located in the atmosphere. Close to the Earth's surface, ground-level or "bad" ozone is harmful to breathe and it damages crops, trees and other vegetation. It is a main ingredient of urban smog. High up in the atmosphere, stratospheric or “good” ozone protects life on Earth from the sun's harmful ultraviolet (UV) rays.
One way to remember whether ozone is “good” or “bad” for us is, "good up high, bad nearby."
Why did EPA release a new standard now?
Under the Clean Air Act passed by Congress, EPA is required to review the health standards for certain pollutants every five years. As part of that review, the agency convenes a group of independent scientific advisors, called CASAC (Clean Air Scientific Advisory Committee), to review the latest health information and make a recommendation.
Most recently, CASAC has advised EPA that the current standard of 75 parts per billion (ppb) is not fully protective of public health and recommended a new stricter standard between 65 and 70 parts per billion (ppb), leaving the policy decision of what standard provides an “adequate margin of safety” (as required by the Clean Air Act) to EPA’s Administrator.
On October 1, 2015, based on extensive scientific evidence about the harmful effects of ozone on public health and welfare, EPA tightened the ozone standard to 70 ppb, providing an adequate margin of safety for at-risk groups, including children, older adults, people with lung diseases, such as asthma, and those who work outdoors.
What happens next?
State and local clean air agencies must now review their air quality data to see if the areas they serve are in compliance with the new standard. EPA will then review the state recommendations and designate areas as either in compliance or not. Areas that are not in compliance (called Nonattainment areas) are required to meet the standard as soon as possible. How long an area has to clean up the air is based on how severe its ozone pollution problem is.
What is the effect of being in ‘nonattainment?’
Besides the impacts on people’s health, areas that are out of compliance will need to develop comprehensive planning processes for attaining the standard by the deadline. Those plans will need to be developed in partnership with all sectors of the local economy – commercial, industrial and transportation – as well as the general public and in some cases neighboring states.
In addition, being in nonattainment may, in some cases, require stricter pollution controls on sources of the chemicals that cause ozone pollution. This results in higher costs for the additional air pollution controls required, as well as costs for emission offsets for major new sources. There may also be additional costs associated with vehicle emissions inspection programs in the nonattainment area.
What can concerned citizens do to help reduce ozone pollution?
We can all take steps to help reduce the chemicals that cause ozone to form. Conserving electricity at home and at work; carpooling, riding your bike or taking public transit; avoiding excess idling and keeping your car well maintained can all help and, in the long run, may save you money.
What are the health benefits of reducing ozone pollution?
EPA estimates the public health benefits of the new standards at $2.9 to $5.9 billion annually in 2025, as compared to estimated costs of $1.4 billion. These annual benefits include the value of avoiding a range of harmful health effects, such as premature deaths, asthma attacks in children, missed school and work days, asthma-related emergency room visits and acute bronchitis in children.
Does EPA look at the costs of a new standard?
Under the Clean Air Act, (as reaffirmed by a unanimous Supreme Court decision), EPA cannot consider the costs when setting the ozone standard. Costs are considered when state and local air pollution control agencies develop regulatory strategies to meet the standards.
Over the last 40 years, the benefits of clean air standards from preventing premature deaths, increased worker productivity and reduced health care costs have far outweighed the costs of cleaning the air. EPA estimates that by 2025, the value of health benefits from the new ozone standard to be $2.9 to $5.9 billion each year.
Where can I learn more about ozone?
Additional information on ozone can be found on EPA’s website at http://www.epa.gov.