Particulate matter not only damages the lungs, but also the cerebral vessels, and already in concentrations that were thought to be harmless. Because the dirty air increases the risk of apoplexy and accelerates the cognitive decline in old age.
The higher the pollution in the air, the higher was in two trials, the risk of stroke and dementia.
With studies on the health effects of particulate matter can now fill entire libraries: The dirt from factory chimneys and car exhausts shortened according to data of epidemiological studies in highly polluted areas around the lives of one and a half years.
In addition, he doubled and tripled the rate of fatal heart attacks, reduced lung capacity in children, promotes asthma, increases blood pressure and also ensures that increasingly clogged brain vessels.
The latter is not only under the strain of the case: A recent study found evidence that particulate matter has values that are classified as harmless to the previous limits, increase the risk of stroke significantly.
Scientists led by Dr. Gregory Wellenius from Providence in the USA have analyzed data from 1,700 stroke patients from the greater Boston area for a period of ten years.
They also looked at the concentration of particulate matter in the region and examined whether there was a connection between exposure to very small, respirable particles (less than 2.5 microns in diameter, PM2, 5) and the incidence of ischemic stroke.
Particulate matter below the limits
All patients had a radius of 40 km around the air monitoring station in Boston, live from the researchers obtained their data.
The remarkable thing: The whole time it was in the region just got a smog alert, the PM2, 5 values were, with the exception of 11 days below the limit of 40 ľg/m3.
At 83 percent of all days, the values were even below 15 ľg/m3 what is considered good air quality (Arch Intern Med 2012; 172: 229).
And yet, the higher the values rose, the more people were admitted with obstructed cerebral vessels in the Boston Hospitals. On days with good air quality standard (15-40 ug/m3) were one-third (34 percent) more than on days with good air quality.
A moderately good air quality is as defined by the U.S. Environmental Protection Agency fact that there is only a small number of people a moderate health risk.
“Assuming, however, assume that almost everyone is exposed to air pollution, then that’s a pretty big effect,” says Wellenius in a statement.
Overall, settled for an increase in the value of PM2, 5 by 10 ľg/m3 an increase in stroke risk by about 17 percent charge.
Especially harmful vehicle emissions
The most common were the strokes 12 to 14 hours after an increase in particulate levels, and indeed especially, when such values also increased, which are typical for car exhaust.
From this they conclude researchers, it appears that a large proportion of the extra strokes on fine dust and exhaust fumes from road traffic is due.
That fine even without the brain damaging stroke and dementia favors, place data close to the Nurse’s Health Study of nearly 20,000 women over the age of 70 years.
A team led by Dr. Jennifer Weuve from Chicago had collected regularly compared cognitive tests of air pollution at the residence of the contributors, over an average of three years (Arch Intern Med 2012; 127: 219).
Takes into consideration not only the respirable dust (PM2, 5), was also the somewhat coarser, more inhalable dust with a particle size up to 10 microns (PM10).
The alarming results: In women, increased cognitive performance at a relatively high long-term exposure decreases significantly faster than in clean air.
In a multi-load of 10 ľg/m3 cognitive performance of older women was about two years of comparable living in areas with good air.
Even a moderate increase of particulate pollution – whether PM2, 5 and PM10 – therefore leaves the brain for two additional years of age.
Data with caution
Here are 10 ľg/m3 not much when you consider that the annual average for PM10 in Germany may be, is four times (Arch Intern Med 2012; 172: 219).
The data are to enjoy but with caution as they only have an association, but does not show a causal relationship.
Other factors as the particulate matter of urban life could be the reason for the accelerated brain aging, such as stress or large social differences with their health consequences.
On the other hand, animal studies suggest that particulate matter may well interfere with brain function by affecting the blood brain barrier and stimulate inflammation.
Significantly elevated levels of inflammatory markers and Alzheimer’s plaques were found at autopsy in the brains of humans and dogs from highly polluted cities.
That the changes in humans and animals were also observed, speaks against a social component.