To: Thomas A Watson who wrote (152313 ) 6/11/2001 9:32:23 PM From: ColtonGang Read Replies (2) | Respond to of 769670 Here's evidence for the Bush administration to move away from fossil fuels and to clean up air pollution...............'Pollution may trigger heart attack' Tiny air particles pose greatest threat to at-risk individuals, study finds Hazy smog blankets Houston last summer. New research finds that as air pollution increases, so does the risk of heart attack. MSNBC NEWS SERVICES June 11 — Exposure for as little as two hours to elevated levels of fine particulate air pollution — the kind in automobile emissions — raises the likelihood of heart attack, especially among people already at risk for cardiac disease, according to a new report. ‘As the level of air pollution went up, the risk went up.’ — DR. MURRAY MITTLEMAN study author RESEARCHERS WHO interviewed 772 Boston-area patients about four days after their attacks found that the onset of symptoms correlated with times of high daily air pollution. Patients experienced a 48 percent rise in heart attack risk in the two hours after exposure to high levels of this type of invisible air pollutants. They also experienced an increased risk even 24 hours after exposure, according to results published in this week’s edition of Circulation, a journal of the American Heart Association. “As the level of air pollution went up, the risk went up,” said Dr. Murray Mittleman, director of cardiovascular epidemiology at Boston’s Beth Israel Deaconess Medical Center, who led the study. “Really, the hazard would be greatest among the people who are at the highest risk to start with,” Mittleman added. Such people include those with established heart disease, conditions such as diabetes or obesity, and older individuals. The study of 489 men and 283 women was conducted from January 1995 to May 1996. The pollution particles are called PM-2.5, for particulate matter less than 2.5 micrometers in diameter. They’re emitted by cars, power plants and industry, as well as fireplaces and wood-burning stoves. Studies in the past five years have linked deaths and hospital admissions to a spike in PM-2.5 levels. The new study did not address how the particles trigger heart attacks. Other studies have shown that the particles, small enough to bypass the body’s defenses and get into the lungs and other tissue, cause inflammation and blood clotting. These symptoms may contribute to heart attacks by blocking flow of blood through the heart, some researchers say. Still other studies have shown that the particles may create electrical reactions that affect the nervous system. BEWARE HOT, HAZY DAYS High amounts of fine particulate air pollution are present typically during very hot, hazy summer days, according to Mittleman. He said people who have heart disease or an elevated risk of heart attack should avoid going outside for long stretches when air quality is poor, and said air conditioning can screen out some of the tiny particles. Researchers noted that Boston does not have excessive pollution and meets federal air quality standards, so the risk could be even worse in high-pollution cities such as Houston and Los Angeles. The Environmental Protection Agency’s air quality standards, last updated in 1997, have been challenged in court in part because no one has pinpointed why pollution particles pose a health risk. Advertisement The study could be used to encourage the EPA to consider stricter air standards, said Dr. Jonathan Samet, chairman of the department of epidemiology at Johns Hopkins University, who was not involved in the study. The researchers also measured for other pollutants including ozone, carbon monoxide, sulfur dioxide and nitrogen dioxide, but failed to find any statistically significant increase of risk for heart attack. The Associated Press and Reuters contributed to this report.