Ozone Not Only Bad For Climate, But Also Bad For The Heart
February 18, 2013

Ozone Not Only Bad For Climate, But Also Bad For The Heart

Peter Suciu for redOrbit.com — Your Universe Online

Ever since the “ozone scare” that began in the 1970s, when it was reported that there was a hole in the ozone over the South Pole, there has been a great misunderstanding about ozone. In the past decade in fact it has only come out that ozone is actually not really good for people.

Most recently researchers at Rice University in Houston have found a direct correlation between out-of-hospital cardiac arrests and levels of air pollution and ozone. While the effects of air pollution have long been understood, ozone has only recently gotten attention for being a toxin.

The American Lung Association had ranked Houston eighth in the United States for high-ozone days, and the Rice researchers looked to find any links between ambient ozone levels and cardiac arrests.

Ozone is also known as trioxygen, a triatomic molecule that consists of three oxygen atoms.

The EPA has noted that ozone is “good up high, bad nearby.” While it acts as a protective layer high above the earth, it is actually harmful to breathe, thus being ground level or “bad” ozone that is not emitted directly into the air. Rather it is created by chemical reactions between oxides of nitrogen and volatile organic compounds in the presence of sunlight.

It was established in the past decade that ozone air purifier devices — those that operate by electrostatic or “ionic” means — don´t actually remove asthma triggers from the air, but in fact produced ozone. Inhaled ozone has long been known to make asthma worse. The EPA has noted the effects that ozone can have on patients with asthma and other chronic respiratory diseases, and deemed it a toxin.

Now the Rice research, announced this week at the American Association for the Advancement of Science (AAAS) conference in Boston, has found a link between cardiac arrests and ozone.

The work by Katherine Ensor, chair of Rice´s Department of Statistics, and Loren Raun, professor in the Department of Statistics, is due to be published in the American Heart Association journal Circulation.

Rice environmental engineer Daniel Cohan also discussed at AAAS how uncertainties in air-quality models could impact efforts to achieve anticipated new ozone standards by the EPA.

For this study, which was funded by Houston Endowment and the city of Houston, the researchers analyzed eight years worth of data drawn from Houston´s network of air-quality monitors, and looked at more than 11,000 concurrent out-of-hospital cardiac arrests (OHCA), logged by Houston Emergency Medical Services. With this, Ensor and Raun found a positive correlation between OHCAs and exposure to both fine particulate matter — airborne particles that are small then 2.5 micrograms — and ozone.

The researchers also looked at the effects of nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO) levels, and none were found to impact the occurrence of OHCAs.

This work could help Houston EMS prepare for those times where weather and/or incidents may warrant an alert for high ozone levels in specific areas. Houston is already acting upon those results.

“The city has targeted educational resources to at-risk communities, where they're now doing intensive bystander CPR training,” said Raun in a statement.

The next step could be in strategies to reduce ozone year-round. The standards are now set at 75 parts per billion, but the EPA is looking to set the new level at 60-70 ppb. This research could have greater implications as states aim to attain national ozone standards.

“The bottom-line goal is to save lives,” said Ensor. “We´d like to contribute to a refined warning system for at-risk individuals. Blanket warnings about air quality may not be good enough. At the same time, we want to enhance our understanding of the health cost of pollution — and celebrate its continuing reduction.”