Nine of the ten regions with the most ozone pollution are in California. High ozone has now been linked to health problems. (eutrophication&hypoxia/Flickr)

Smog has been linked to heart problems and even death, and new research by the U.S. Environmental Protection Agency begins to explain why.

Researchers found that healthy young adults who have been exposed to ozone – which is a major component of smog – experience physiological changes that could be linked to heart ailments in vulnerable populations, such as elderly people with cardiovascular disease. Additionally, the study “provides a plausible explanation for the link between acute ozone exposure and death,” lead author Robert B. Devlin said in a statement.

The study has special implications for Californians, who are exposed to some of the highest ozone levels in the country.

Of the 10 regions in the country with the most ozone pollution, nine are in California, with Los Angeles-Long Beach-Riverside topping the list, according to the American Lung Association.

“Our ozone problem is the result of the combination of population, climate, terrain and industry,” with car exhaust as the main source of the pollutant in California, Dimitri Stanich, a spokesman for the California Air Resources Board, wrote in an email. “California has historically had the worst air pollution in the union. In the 1940s, there were smog events in the L.A. area where residents couldn’t see a city block.”

Ozone is created when pollutants from cars, power plants and other sources interact with sunlight.

To address ozone pollution, the air resources board requires car manufacturers to meet more stringent emission standards and regulates some chemical-based consumer products that may contribute to ozone during evaporation.

In its new study, EPA researchers exposed 23 healthy young adults to two-hour sessions of both clean air and ozone-polluted air at levels about two times greater than what residents in China or Mexico experience during the middle of the day. After exposure to the pollutant, the study subjects saw an increase in various cardiovascular indicators that could result in heart problems in people with heart disease, including vascular inflammation and a reduced ability to dissolve artery-blocking blood clots.

Though studies of ozone and human health abound, the new EPA study, published in the American Heart Association journal Circulation, is among the first to use human volunteers to explain how ozone can potentially kill people by causing heart attacks. Previous epidemiological studies have shown a connection using statistical analyses.

“It’s the strongest evidence that there is a true causal connection” between ozone exposure and heart health, and confirms and expands what has been suggested in previous studies, said Douglas Dockery, an environmental epidemiology professor at Harvard’s School of Public Health.

Health experts said that the latest EPA study is an important contribution to determining the extent of the relationship between ozone exposure and cardiovascular problems – an issue that is far from scientifically settled.

A larger, 90-person study among the elderly was recently launched by the Boston-based Health Effects Institute in conjunction with UC San Francisco and two other universities.

“There is not a universal set of studies that say, ‘Yeah, ozone definitely contributes to cardiovascular effects,’ ” said Dan Greenbaum of the Health Effects Institute. “But that may be because we have not looked at it the right way, and that is what we are trying to do with this study (of the elderly).”

Joe Lyou, a governing board member of the South Coast Air Quality Management District and the CEO and president of the Coalition for Clean Air, said more could be done at a policy level to address the health impacts of ozone pollution.

“We need to move toward zero and near-zero emission transportation for both people and freight,” he said in an email. “In order to meet our clean air standards, we have to focus on the combustion of petrochemical fuels and identify ways to minimize and eliminate it. If we do it right, we can increase energy efficiency, reduce our dependency upon foreign oil and save boatloads of money.”

The EPA is currently reviewing the national air quality standards for ozone and will issue a final rule in 2014. In preparation, a draft scientific assessment was recently released by the agency for public comment, and it states that the current health research is “suggestive of a causal relationship” between the pollutant and cardiovascular effects. The agency’s Clean Air Scientific Advisory Committee Ozone Review Panel, however, had previously recommended that the EPA upgrade this determination to “likely to be a causal relationship.”

In September, the Obama administration rejected a proposed rule from the EPA to tighten the federal air quality standards related to ozone pollution. In a statement, the president cited the “importance of reducing regulatory burdens and regulatory uncertainty, particularly as our economy continues to recover.”

More information

The U.S. Environmental Protection Agency has more on how to limit ozone exposure.

Dr. Margaret Hamburg, FDA Commissioner. (US Mission Geneva: Flickr)

Last week, the big story may have been the Susan G. Komen Foundation’s flip-flopping over funding Planned Parenthood. But coming in a close second (at least here at the health desk) was the call for regulating sugar in the same way alcohol and tobacco are. The argument was made by UC San Francisco researchers in the journal Nature. They laid out the science that sugar is behind many of the chronic maladies we see today–diabetes, heart disease and high blood pressure.

Today FDA Commissioner Margaret Hamburg was a guest on KQED’s Forum. Host Michael Krasny asked her if sugar should be removed from the FDA’s “GRAS” category–that’s for Generally Recognized as Safe. Not surprisingly, the Commissioner did not announce imminent action. She said she did have a chance to “look quickly at the initial report” and that “we’ll look very seriously at any new data that’s presented.”

In other words, nothing will be happening soon, just as researcher Robert Lustig expected when I talked to him last week. The commentary was an “opening salvo,” he said. “Nothing in public health changes overnight. It’s not possible to.”

Here’s the Commissioner’s complete response to Krasny’s question:

Sugar is one important area of nutrition where there’s enormous interest in deepening our understanding of the health risks and benefits. It’s an area where consumers want to know more about what’s in the food that they’re eating and where the FDA has a critical role to play in terms of both supporting and building on important new research insights and through our responsibilities for providing accurate information about the content of processed foods.

As the Commissioner continued speaking, she seemed in this next section to be choosing her words very carefully:

So, it’s an important area that sugar, along with other critical nutritional issues, such as sodium and saturated fats and overall calories all require strengthening our understanding of the science and really understanding individual and public health issues and linking that to what we do at the FDA.

Then she picked up steam again here:

But I have had a chance to look quickly at this initial report, I understand the request that’s being made. We’ll look very seriously at any new data that’s presented. In the meantime, consumers should be aware that nutritional information is provided on the back of processed food packages that enables them to look at the relative contribution of different types of sugars in the foods that they’re eating along with other nutritional components and it’s an opportunity to make more informed choices about the food they eat and the food they serve their families.

More:

The Trouble with Sugar on Forum, February 2, 2012