Science committee says U.S. ozone limits are too high

According to the latest regional air quality forecast for today, levels of ozone are in the “green” range.

The lung-searing, potentially deadly stuff -- also referred to as smog -- that forms when chemicals from fossil fuel combustion and sunlight react is not at dangerous levels, which could cause or exacerbate asthma, other respiratory problems and heart disease.

But that may not be true.  It all depends on what you call a dangerous level.

For years, the U.S. Environmental Protection Agency has maintained that a level of 75 parts per billion is okay. Even though its own scientific advisory committee recommended a lower level.

Now, that committee has reiterated and reinforced its view.

Health advocates said today that the committee sent a new letter to the EPA, contending the current ozone national air quality standard fails to protect public health and should be significantly strengthened.

“And their letter is a doozy,” said Frank O’Donnell, of the national advocacy group, Clean Air Watch, in an email to reporters. “The scientists not only note that the current standard of 75 parts per billion is too weak — but that the top part of their own recommended range (60 to 70) may be illegally weak as well!”

As the letter says, “At 70 ppb, there is substantial scientific evidence of adverse effects as detailed in the charge question responses, including decrease in lung function, increase in respiratory symptoms, and increase in airway inflammation. Although a level of 70 ppb is more protective of public health than the current standard, it may not meet the statutory requirement to protect public health with an adequate margin of safety.”

O’Donnell said the EPA has been “skittish about this key public health issue” since an effort to set a stricter limit failed in 2011.

“It's going to be tough for EPA to sweep this issue under the rug in light of the scientists' letter,” he said.

The committee is an independent group of scientists, physicians, researchers and air pollution experts who have been reviewing hundreds of studies and analyses of the health effects of ozone for several years, noted Janice Nolen, assistant vice president of national policy for the American Lung Association.

One of its seven members is Ana Diez-Roux, dean of Drexel University's School of Public Health.

Nolen called for the EPA to propose a standard of 60 ppb.

The committee “has told EPA multiple times before that the current standard of 75 ppb failed to protect public health,” she said in a prepared statement. “The Lung Association hopes that this time the EPA will follow the recommendations from CASAC, unlike in the previous formal review that ended in 2006 and the reconsideration of the standard that ended in 2011.”

"Ozone is the most widespread air pollutant and is known to cause coughing, wheezing, and asthma attacks and increases the risk of hospital admissions and emergency room visits, as well as the risk of premature death,” she said.

“New evidence links ozone to a broad array of other health threats as well, including cardiovascular harm, low birth weight in newborns and loss in short-term memory. Children, teenagers, seniors, people with lung diseases such as asthma, and people with cardiovascular disease are especially at risk from the harms of ozone pollution,” Nolen said. “Even healthy adults who work and exercise outdoors face greater risk from ozone pollution.”

The full letter and attachments -- 75 pages in all -- is here:

Even at the current standard, every county in the region except for Burlington — which is an unknown because it has no monitor — fails to meet ozone limits.

According to the annual “State of the Air” report released by the American Lung Association in April, the broader region, from Berks County to Cape May County, ranks 16th in the nation for ozone pollution.