Word: brookes
(lookup in dictionary)
(lookup stats)
Dates: during 2000-2009
Sort By: most recent first
(reverse)
...This is a major step forward in understanding the mechanism of how air pollution causes heart disease," says Brook. Now that we know how damaging polluted air can be on our hearts, clean air is not just a matter of the planet's health, but ours...
Scientists at the University of Michigan, led by Dr. Robert Brook, found that the quality of air you breathe can immediately increase your blood pressure, and cause unhealthy changes in your blood vessels that last for hours and perhaps even days. The study measured the effect of air pollution in healthy people in two cities - Ann Arbor, Mich., and Toronto - where participants were exposed in the lab to the same amount of particulates and ozone that would be found near a local highway. People who breathed in polluted air registered higher blood-pressure readings a short time after exposure, compared...
...Brook's data suggest that particulates are more active players in heart problems than ozone, and that two different processes may be occurring as we inhale unclean air. First, the fine matter triggers changes in the central nervous system, causing a switch from the more controlled regulation of body processes to a more instinctive, automatic fight-or-flight response. This revs up the heartbeat and causes blood pressure to spike as the body may be responding to the presence of foreign, potentially dangerous particles in the air. (See pictures of the world's most polluted places...
...that doesn't mean that every urban resident is at higher risk of heart disease. For most healthy people, the exposure to city air and transient changes in blood pressure isn't dangerous. But, says Brook, "it's plausible that if someone has underlying hypertension or coronary disease, then these changes in blood pressure and blood-vessel function might be exaggerated and might even trigger a heart attack. The levels at which we encounter these particles today is still dangerous to people who are unhealthy and at high risk." (See pictures of the effects of global warming...
...average North American city contains about 14 micrograms of particles per cubic meter of air - a vast improvement, thanks to clear-air laws, over the amounts found more than a decade ago. Brook's team studied much higher exposures to particulates, in the order of 150 micrograms per cubic meter, but notes that on many days, cities such as Los Angeles and Pittsburgh and Detroit often reach these levels. (The Environmental Protection Agency deems anything between 151 and 200 micrograms per cubic meter to be unhealthy.) But it's hard for the average city denizen to know when particulate levels...