New Texas Study Confirms That Smog is Bad For Your Heart

Heart attacks are more common within just hours of high ozone and/or particulate matter levels according to a new large study of air pollution health effects that was sponsored by Rice University.

Evidence already links airborne particles with heart disease and lung problems but the new findings are the first to show that high ozone may immediately raise the risk that a person's heart will stop beating.

"Heart patients should consider when there are high ozone levels that they should take extra care of themselves," lead author Katherine Ensor of Rice University in Houston told Reuters Health.

Ensor and her colleagues looked at Houston hospital records from 2004 to 2011 and compared them with records from hospitals outside the city.

Cardiac arrest risk went up by 4.4 percent for every 20 parts per billion of ozone above average (50-60 ppb) within the previous three hours. For every increase by 6 micrograms of fine particulates per cubic meter of air in the prior two days, cardiac arrests rose by 4.6 percent. In the summer, it's not unuual for DFW monitors to record 1-hour ozone levels of over 100 ppb or more, and 8-hur averages in the 80 to 90 ppb range.  There are only two urban monitors for PM pollution, but those have been trending up over the last few years as ozone levels have been rising as well.

Because there are many risk factors for cardiac arrest, an additional link to ozone could have big implications for people with chronic medical conditions living in urban areas, according to Dr. Comilla Sasson of the University of Colorado, who was not involved in the new study.