Increase in City’s Ozone Levels Up Risk of Cardiac Arrest

A latest study from Texas shows an association between the levels of air pollution and cardiac arrests.

According to the study lead by researchers at the Rice University in Houston, U.S., an increase in the city's ozone levels may increase the risk of cardiac arrest.

In order to prove the hypothesis, the researchers analyzed information of more than 11,600 people residing in Houston, Texas. These people had already suffered a cardiac arrest out of the hospitals between 2004 and 2011. Apart from this, the researchers also gathered information on the ozone levels, the main component of smog from almost 44 different monitoring stations in the city.

They noticed that more than 11,000 cardiac arrests are caused without any traumatic injury, and the cardiac arrests were high when there was a slight increase in the ozone layer.

Prior to this, there were studies done that linked airborne particles with heart disease and lung problems, but this is the first study that links high ozone levels to an immediate risk of cardiac arrest.

According to the researchers, a rise in ozone levels of 20 parts per billion (ppb) over a three-hour period was linked to a 3-4 percent increase in risk of suffering from cardiac arrest.

"During the summer months, it would not be uncommon for the ozone levels in Houston to increase from about 60 to 80 ppb over a three-hour period," Katherine Ensor, a statistician at Rice University in Houston and a study author, was quoted as saying in Sudan Vision.

She also cautions heart patients to take extra care when the ozone levels are high.

According to the Environmental Protection agency, ozone is not just emitted from cars or factories, it also forms when pollutants from these sources come in contact and react. The reaction is triggered by sunlight. Apart from cardiac arrest, inhaling ozone can trigger chest pain, throat irritation and coughing.

The study was published in the journal Circulation.