Air Pollution Linked to Stroke and Heart Disease
Two recent research studies found air pollution can raise the risk of stroke and contribute to heart disease. The first study examined medical records of 1,705 Boston area patients who had been hospitalized with ischemic stroke. Researchers then studied environmental data on vehicle emissions such as particulate matter, black carbon, and nitrogen dioxide. Their study revealed strokes are more likely to happen right after a 24-hour period when air pollution worsens. The chance of having a stroke was 34% higher on a day with a moderate level of air pollution compared to a day with a good level. Strangely, even though the increase in air pollution was found to have a connection with ischemic stroke, the EPA apparently considers that level to be safe.
The researchers estimated a 20% reduction in fine particulate matter could have prevented 6,100 strokes that occurred in the northeast in 2007.
The second study was a meta-analysis (review) of 34 studies of air pollution and heart disease. Particulate matter, carbon monoxide, nitrogen dioxide, and sulfur dioxide which are all emitted by vehicles as air pollution and were found to be linked with a slight increase in the risk of heart attack in the short-term.
Fine particulate matter is emitted in vehicle exhaust, and when inhaled can cause inflammation in the body’s tissues. Researchers from both studies agreed reducing exposure to air pollution for people who are at risk of stroke or heart attack would be beneficial, but said the main causes of these diseases are related to lifestyle choices such as diet, exercise and not smoking.
Another study of vehicle emissions, specifically from diesel trucks and buses, found their ultrafine particulate matter can increase the risk of heart attack and stroke. One of the researchers said people with heart disease should try to limit their exposure to diesel exhaust by not remaining near busy roads for long periods.
For people living in highly polluted cities, could there be a greater effect due to the fact their heart disease was caused in part by having lived in a city for many years, and such spikes in air pollution can increase the chance of a heart attack or stroke event?
Long-time city dwellers might have a very difficult time moving out of an urban culture they presumably enjoy, and leaving behind their established social life, even if it is better for their health. Clean, renewable energy is one possible solution, because as we become less dependent fossil fuels, air pollution levels should decline.
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