DOC WARNS POLLUTION AND POT INCREASE RISK OF CARDIAC WOES

Just two hours outside on a day when air pollution is at a high level may
be enough to significantly increase the risk of a heart attack among the
elderly or those with histories of heart disease, a study says. The Beth
Israel Deaconess Medical Center study is the first to show that brief
exposure to elevated levels of fine particulate air pollution can hike the
risk of a heart attack by 50 percent among those already at increased risk.
On such days, those at high risk ``should limit their outside activities,''
said Dr. Murray Mittleman, lead author of the paper in Circulation. ``Spend
less time outside and do less vigorous activities on those days. This is
especially the case on the hot, hazy days of summer when the problem is
much more prominent.'' The researchers interviewed 722 people shortly after
they were admitted to Boston area hospitals for heart attacks.

Most had suffered a previous heart attack or had high blood pressure,
diabetes, were obese or were smokers. The researchers also measured for
concentrations of several air pollutants at several Boston sites.

An analysis of the data showed that study participants had nearly a 50
percent increased risk of heart attack in the two hours after exposure to
high levels of fine particles.

The researchers also observed a delayed response associated with an
increased risk 24 hours after exposure to high levels of fine particles. A
second Mittleman study, also in Circulation, showed that baby boomers who
smoke marijuana may also increase their risk of heart attack.

In a study of nearly 4,000 people who had suffered a heart attack, the
chance of suffering another heart attack increased nearly five times during
the first hour after smoking a joint.

Their risk increases from about 10 chances in a million to 50 chances in a
million, according to Mittleman. The findings were previously reported at
an American Heart Association conference in March 2000. A healthy baby
boomer increases his or her risk from one chance in a million to about five
chances in a million, he said. ``Marijuana use in the age group prone to
coronary artery disease is higher than it was in the past,'' Mittleman
said. While the increased risk is tiny, Mittleman said the findings should
give pause to advocates of medicinal marijuana. ``For some people it might
not be appropriate,'' he said.