Higher stroke risk and memory loss it's in the air

Two studies find air pollution plays a role

Crowded cities, vehicle emissions, busy highways, industrial fumes all causes of poor air quality and could be linked to a higher stroke risk and cognitive decline according to new search from two sources.

One study conducted by researchers at Brown University finds a higher risk for stroke especially when traffic related pollution was high. This study is published in the Archives of Internal Medicine, on Monday.

The second study from Rush University Medical Center found chronic exposure to particulate air pollution may hasten cognitive decline in older women. This study also appears in the same journal.

Dr. Gregory Wellenius, ScD, professor of Epidemiology at Brown and lead author of the stroke study stated "One of the important points is that at levels that are considered to be generally safe by the U.S. EPA, we're seeing important health effects.”

Dr. Wellenius and associates examined medical records of about 1,700 patients who had been admitted to Beth Israel Deaconess Medical Center in Boston with a stroke between 1999 and 2008.

Using information from a local air pollution monitoring station, researchers found the risk of having a stroke was 34% higher within 24 hours after “moderate” EPA pollutant readings in comparison to “good” pollution days. That higher risk was strongest within 12 to 14 hours of pollution exposure and was associated to the traffic related pollutant of nitrogen dioxide.

According to Dr. Wellenius, blood vessels dilate and constrict in response to the outside environment in an attempt to keep the blood pressure constant. He further notes that air pollution may affect the bodies to regulate blood pressure which could trigger a stroke in people who are already at risk.

This same effect may explain why over an extended period of time being exposed to air pollution may be linked with declined thinking and memory skills.

In the other study led by Dr. Jennifer Weuve, MPH, ScD, assistant professor of internal medicine at Rush University Medical Center in Chicago, found air pollution is linked to faster cognitive decline.

Dr. Weuve and associates evaluated air pollution both course and fine in association to cognitive decline in older women. Researchers used a study population from the Nurse's Health Study Cognitive Cohort which had included 19,409 women in the U.S., aged 70 to 81, for a fourteen year period going back as far as 1988.

Researchers had discovered that more air pollution was linked to a faster cognitive decline

According to Dr. Weuve, very little is known about the role of particulate matter exposure and its association with cognitive decline. Particulate air pollution exposure is linked with cardiovascular risk, which itself could play a part in causing and accelerating cognitive decline.

Dr. Weuve states “Unlike other factors that may be involved in dementia such as diet and physical activity, air pollution is something we can intervene on as a society at large through policy, regulation and technology.”

In closing Dr. Weuve notes if their “findings are confirmed in other research, reducing air pollution is a possible means for reducing the future population burden of age-related cognitive decline is something that can be intervened on as a society at large through public policy, regulation and technology.”

The findings of either study can confirm that pollutants by themselves are at fault for memory problems and stroke. Past studies do support negative health effects on the heart and blood vessels.

Researchers note that for broad health benefits, the EPA might have to reconsider acceptable upper limits of air pollution

The State of Air 2011 Report by the American Lung Association shows that air quality in many places has improved but over 154 million Americans, a little over half the nation, still endure pollution levels that are often dangerous to breathe. In that report Detroit had ranked in 17th place.

Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later.

Immediate effects may show up after a single exposure or repeated exposures. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. Sometimes the treatment is simply eliminating the person's exposure to the source of the pollution, if it can be identified. Symptoms of some diseases, including asthma, hypersensitivity pneumonia, and humidifier fever, may also show up soon after exposure to some indoor air pollutants.

For indoor air quality indoor air purifiers can be purchased. Depending on the type they can trap indoor allergens such as smoke, filters turn smog and ozone into pure air plus they use about the same amount of electricity as a night light plus they are silent.

To check air quality in Detroit it can be viewed on Weatherbug.