Ozone reaching dangerous levels in parks

Millions of individuals who visited U.S. national parks in 2011 were exposed to dangerous concentrations of ozone (O3).

The Environmental Protection Agency’s National Ambient Air Quality Standard (NAAQS) for ozone — currently 75 parts per billion — was exceeded on countless occasions during the ozone season. According to the National Parks Conservation Association, this spans from April through October.

The National Park Service considers it an “exceedance” if the maximum eight-hour ozone concentration in a park on any particular day violates the NAAQS. In 2011, 262 total exceedances of the standard were reported, a three-year high.

At right, Giant sequoias trees are a main attraction at Sequoia and Kings Canyon National Parks, but their population is being threatened by a rising mortality rate (Photos courtesy of the National Park Service). Below hiking and other strenuous activities are risky for all individuals if ozone exceeds that National Ambient Air Quality Standard.

The NPCA declared “Code Red” days in those instances. This draws attention to “the serious threat they [exceedances] pose to healthy breathing,” Stephanie Kodish of the association’s Clean Air Counsel said in a September press release.

Dr. Jonathan Levy is an adjunct professor of environmental health at the Harvard School of Public Health. Through quantitative research, he assesses the environmental and health impacts of air pollution. He explained that humans are at risk when exposed to high concentrations of ozone.

“There’s a host of different respiratory effects that you might expect to see,” Levy said. “At those levels of exposure over a short term basis, you have lung function impact, general difficulty breathing, symptoms among people with asthma, and other respiratory diseases.”“People tended to exhibit declines in lung function, and other respiratory symptoms,” Levy said, even when they are exposed to lesser concentrations of ozone during controlled experiments.

Unfortunately, premature death is possible at high concentrations.

Air resources specialist Annie Esperanza of the National Park Service is stationed at Sequoia and Kings Canyon National Parks. Although she didn’t witness any ozone-induced emergencies at the parks in 2011, she admitted that she “wouldn’t be surprised” if several had transpired in recent months.

After all, exceedances were the norm at Sequoia and Kings Canyon this past visiting season. Both are located in the southern Sierra Nevada in California.

Esperanza cited 2002 and 2008 as examples of “banner years” for ozone exceedances. Although she was relieved that air quality in 2011 wasn’t quite as dangerous, she said that the parks themselves aren’t in control.

“Ozone requires precursors or other chemicals,” she explained, “and most of the chemicals come in from outside the park’s boundary. There’s not a lot we can do in terms of any kind of regulatory actions. We don’t have that kind of power as a national park.”

The Environmental Protection Agency plays an essential role in regulating air quality—it sets the NAAQS, remember? However, the U.S. Congress is beginning to challenge the EPA’s authority.

In September, the U.S. House of Representatives adopted the Transparency in Regulatory Analysis of Impacts on the Nation Act of 2011 (also known as the TRAIN Act).

This piece of legislation requires the president to form a committee whose purpose is to review notable EPA rules. Eight are specifically named in the original bill, including the NAAQS for ozone. Analysis will be performed to determine whether or not these rules are justified. The committee has the power to suspend any rule that it finds unsatisfactory.

Rachel Cleetus is an economist with the Union of Concerned Scientists, a nonprofit organization that does independent research to arrive at environmental solutions.

She was critical of the TRAIN Act upon its adoption on September 21. She went as far as calling it “a colossal waste of money” in a UCS press release. Cleetus deemed “EPA regulations critical to protect our health” and “incredibly cost effective.”

Based on information from the Office of Management and Budget, she said that the EPA saved the United States hundreds of billions of dollars in potential health costs between October 2000 and September 2010. This dwarfs the tens of billions it spent on enforcement of regulations during that period.

If anything, the EPA ought to receive more funding because in addition to humans, tree populations across the country are suffering.

Veteran research ecologist Dr. Nate Stephenson of the United States Geological Service is stationed at Sequoia and Kings Canyon National Parks. He has helplessly observed tree mortality rates double for various species at his own parks over the last several decades, as well as in areas of the Rocky Mountains and American Southwest.

The reduced number isn’t apparent to visitors . . . yet. Stephenson imagines, though, that people will be deterred from coming by if and when the absence becomes noticeable.

“If you’re walking through the forest and half the trees are dead,” he said hypothetically, “that’s going to impinge upon your experience.”

The affected sites have all experienced rises in temperature over the years. “We think that it’s more likely to do with climate than it is with ozone,” Stephenson concluded.

However, research from the Department of Atmospheric and Oceanic Science at the University of Maryland, College Park suggests that a relationship exists between the two.

Families can be hesitant to visit national parks because children can be affected by the slightest ozone exceedances.

Dr. Russell Dickerson—an affiliate chemistry professor at Maryland—coordinated the study and published the group’s ultimate findings. Using data from the past 21 years, he approximated that “the slope of the ozone-temperature relationship . . . was about 3.2 ppb O3/C” in rural areas. Therefore, it is clear that to some extent, the EPA can affect climate change and tree populations by regulating surface ozone.

A Southern California native, Stephenson recalled days from his youth when pollutants combined into a “fog.”

“Air pollution was really bad,” he said. “I can remember playing as a kid and feeling this ache in my lung from the pollution.” Thankfully, air quality is no longer so blatantly malignant.

Still, conditions could be better. Esperanza said the Clean Air Science Advisory Committee (CASAC) that advises the EPA recommends an ozone standard of 70 parts per billion.

Furthermore, the World Health Organization insists it be lowered to 50 parts per billion. Esperanza did her best to hold back laughter when explaining that “it would almost be impossible to reach that without removing every industrial part of our world.”

“You wouldn’t necessarily see all the health implications go away” at any minimized ozone concentration, said Levy, but one thing is certain—we aren’t as safe as we could be.

As the next ozone season approaches, precautions need to be taken, especially in national parks.