A new research from the US warns that air pollution and ozone levels may also play a role in precipitating heart attacks.

Rice University (Houston) statisticians Katherine Ensor and Loren Raun analysed eight years’ worth of data drawn from Houston’s extensive network of air-quality monitors and more than 11,000 concurrent out-of-hospital cardiac arrests (OHCA) logged by Houston Emergency Medical Services (EMS). ‘The bottom-line goal is to save lives,’ Ensor said. ‘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.’

The researchers found a positive correlation between OHCAs and exposure to both fine particulate matter (airborne particles smaller than 2.5 micrograms) and ozone, the American Heart Association journal Circulation, reports. They found that a daily average increase in particulate matter of six micrograms per day over two days raised the risk of OHCA by 4.6 percent, with particular impact on those with pre-existing (and not necessarily cardiac-related) health conditions, according to a Houston statement.

For the study, OHCA events were defined as cases where EMS personnel performed chest compressions. Ensor and Raun noted that the patients died in more than 90 percent of the cases, which occurred more during the hot summer months (55 percent of total cases). The researchers also looked at the effects of nitrogen dioxide, sulphur dioxide and carbon monoxide levels, none of which were found to impact the occurrence of OHCA. These findings were presented at the American Association for the Advancement of Science (AAAS) conference in Boston.

According to a Global Burden of Disease (GBD) report, outdoor air pollution has become the fifth largest killer in India after high blood pressure, indoor air pollution, tobacco smoking and poor nutrition. The report says that about 620,000 premature deaths occur in India from air pollution-related diseases. It also highlights that annual premature deaths caused by particulate air pollution have increased by six times since 2000 and accounts for one fifth of global deaths.

The air pollution-induced premature deaths are caused by respiratory and cardiovascular diseases. These diseases include stroke (25.48 percent), chronic obstructive pulmonary disease (17.32 percent), ischemic heart disease (48.6 percent), lower respiratory infections (6.4 percent), and trachea, bronchus and lung cancer (2.02 percent). Heavy emission of half-burnt gases and fuel is also the main reason for the heavy winter smog and the bad air. Smog is a serious problem because it is harmful for health especially for children, elderly, and for people with heart and lung conditions like asthma and bronchitis. It can cause eye and nose irritation, dryness of nose and throat, wheezing, coughing, asthma attacks, etc. With regular long-term exposure, it may cause lung cancer.

With inputs from IANS