Featured Research

from universities, journals, and other organizations

Diesel Exhaust Associated With Higher Heart Attack, Stroke Risk In Men

Date:
November 10, 2007
Source:
American Heart Association
Summary:
Increased roadway pollution produced by diesel fuel in vehicles is leading to a cascade of conditions that could result in heart attack or stroke, researchers suggest. They found that diesel exhaust increased clot formation and blood platelet activity in healthy volunteers -- which could lead to heart attack and stroke.

High levels of traffic pollution are known to increase the risk of heart attack in the immediate hours or days after exposure, experts say.
Credit: iStockphoto/Larry Lawhead

Increased roadway pollution produced by diesel fuel in vehicles is leading to a cascade of conditions that could result in heart attack or stroke, researchers suggest.

United Kingdom and Swedish researchers found that diesel exhaust increased clot formation and blood platelet activity in healthy volunteers -- which could lead to heart attack and stroke.

"The study results are closely tied with previous observational and epidemiological studies showing that shortly after exposure to traffic air pollution, individuals are more likely to suffer a heart attack," said Andrew Lucking, M.D., lead author of the study and a cardiology fellow at the University of Edinburgh in the United Kingdom. "This study shows that when a person is exposed to relatively high levels of diesel exhaust for a short time, the blood is more likely to clot. This could lead to a blocked vessel resulting in heart attack or stroke."

The double-blind, randomized, cross-over study included 20 healthy men, 21 to 44 years old. They were separately exposed to filtered air (serving as a control) and to diluted diesel exhaust at 300 micrograms per meter cubed (mcg/m3), a level comparable to curbside exposure on a busy street.

Researchers performed the exposures in a specially built diesel exposure chamber. At two hours and at six hours after exposure, researchers allowed a small amount of participants' blood to flow through a perfusion chamber. They measured clot formation, coagulation, platelet activation and inflammatory markers after each exposure.

To measure clot formation, researchers used low and high shear rates, recreating flow conditions inside the body's blood vessels. Compared to filtered air, breathing air with diluted diesel exhaust increased clot formation in the low shear chamber by 24.2 percent and the high shear chamber by 19.1 percent. This was seen at both two and six hours after diesel exposure.

The researchers also found an increase in platelet activation, assessed by measuring the number of platelets associated with white blood cells. Platelets play a central role in blood clotting, and when they are activated, they associate with white blood cells such as neutrophils and monocytes, Lucking said. Diluted diesel exhaust inhalation increased platelet-neutrophil aggregates from 6.5 percent to 9.2 percent and platelet-monocyte aggregates from 21 percent to 25 percent at two hours after exposure. At six hours, researchers found a trend toward platelet activation, but it was not statistically significant.

"After exposure to diesel exhaust, the participants had increased levels of activated platelets that became attached to white blood cells," he said. "When activated, the platelets can stick together and form a clot.

"High levels of traffic pollution are known to increase the risk of heart attack in the immediate hours or days after exposure. These findings provide a potential mechanism that could link exposure to traffic-derived air pollution with acute heart attack." It's unclear whether these findings would apply to gasoline-powered engines, Lucking said. Diesel engines generate many times more fine pollutant particles than comparable-sized gasoline engines.

"Diesel engines are becoming very popular because of increased fuel economy," Lucking said. "While diesel engines burn more efficiently, they also put more fine particulate matter into the air."

Lucking encourages physical activity but suggested that people with existing cardiovascular disease try to exercise away from traffic congestion.

The researchers plan to collaborate again with researchers at the University of Umea, Sweden, to test particle traps retrofitted on diesel engines to determine whether these devices are effective in reducing diesel particles.

"Exposure to air pollution clearly is detrimental and we must look at ways to reduce pollution in the environment," Lucking said. The U.S. Environmental Protection Agency (EPA) introduced its 1997 National Ambient Air Quality Standards (NAAQS) to educate the public about daily air quality levels, including information about ozone and particulate matter levels.

The American Heart Association supports these EPA guidelines for activity restriction for people with heart disease or those who have certain cardiovascular risk factors, for people with pulmonary disease or diabetes and for the elderly.

A report of this small study was presented at the American Heart Association's Scientific Sessions 2007.

Co-authors are Magnus Lundback, M.D.; Nicholas L. Mills, M.D.; Dana Faratian, M.D.; Fleming Cassee, Ph.D.; Ken Donaldson, Ph.D.; Nicholas Boon, M.D.; Juan J. Badimon, M.D.; Thomas Sandstrom, M.D., Ph.D.; Anders Blomberg, M.D., Ph.D.; and David E. Newby, M.D., D.M., Ph.D.

The British Heart Foundation funded the study.


Story Source:

The above story is based on materials provided by American Heart Association. Note: Materials may be edited for content and length.


Cite This Page:

American Heart Association. "Diesel Exhaust Associated With Higher Heart Attack, Stroke Risk In Men." ScienceDaily. ScienceDaily, 10 November 2007. <www.sciencedaily.com/releases/2007/11/071106092015.htm>.
American Heart Association. (2007, November 10). Diesel Exhaust Associated With Higher Heart Attack, Stroke Risk In Men. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2007/11/071106092015.htm
American Heart Association. "Diesel Exhaust Associated With Higher Heart Attack, Stroke Risk In Men." ScienceDaily. www.sciencedaily.com/releases/2007/11/071106092015.htm (accessed April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins