It's Something in the Air: Pollution and Health

Air pollution may increase risk of stroke and anxiety

(RxWiki News) You've got to breathe to live, but breathing polluted air could put you at risk of health problems.

A new research review found that air pollution may cause high blood pressure and increase the risk of stroke. Another new study found that the particles in air pollution may increase the risk of anxiety in women.

These studies were observational, which means they don’t show a clear cause-and-effect tie to air pollution. However, an editorial about these studies noted that reducing air pollution could improve the health of many people.

Editorial author Dr. Michael Brauer, a professor at the School of Population and Public Health at the University of British Columbia in Vancouver, wrote, “The findings of these two studies support a sharper focus on air pollution as a leading global health concern. They also suggest opportunities for reducing the prevalence of two debilitating and common diseases. One of the unique features of air pollution as a risk factor for disease is that exposure to air pollution is almost universal. While this is a primary reason for the large disease burden attributable to outdoor air pollution, it also follows that even modest reductions in pollution could have widespread benefits throughout populations."

The first study was led by Anoop S. V. Shah, MD. Dr. Shah is a clinical lecturer in cardiology at the University Centre for Cardiovascular Science at the University of Edinburgh in Scotland.

Dr. Shah and colleagues performed an extensive review of scientific literature called a meta-analysis. The data included 103 studies from 28 countries around the world.

As carbon monoxide and other substances in the air increased, so did hospital admissions for stroke or death from stroke, these researchers found. Dr. Shah and team also found that the first day of air pollution exposure was most closely tied to an increased risk of stroke.

Middle- to low-income countries were more likely to have highly polluted air than higher-income countries. Dr. Shah and team called for policy changes to reduce exposure to air pollution.

The second study used data from the long-running US Nurses’ Health Study. It was led by Melinda C. Power, a postdoctoral fellow in the Department of Epidemiology at the Harvard School of Public Health in Boston.

The study group included more than 71,000 women who were assessed for anxiety at an average age of 70.

Dr. Power and colleagues assessed the women’s exposure to air pollution over various periods of time.

About 15 percent of these women reported high levels of anxiety, Dr. Power and team found. Women exposed to particles found in air pollution had an increased risk of anxiety. The effects appeared to be stronger in the first month after exposure.

Both studies were published March 24 in The BMJ.

Dr. Shah and team were funded by a British Heart Foundation grant. Three of the study authors received funding from the British Heart Foundation. No conflicts of interest were disclosed.

Dr. Power's study was funded by grants from the National Institute of Environmental Health Sciences. Dr. Power received a training grant from the National Institute on Aging. These researchers disclosed no conflicts of interest.

Review Date: 
March 24, 2015