Thunderstorms have hospitalized 52K Americans for breathing issues, study says. Why?

Older adults suffering from common chronic respiratory diseases such as asthma should take extra precautions when conditions are ripe for thunderstorms.

New research shows the cocktail of lightning, rain and strong winds has been responsible for thousands of emergency room visits for breathing problems among older adults over a 14-year period, according to a study published Monday in the journal JAMA Internal Medicine.

Unlike past studies that have blamed increased pollen counts during storms for the uptick in respiratory issues, this paper found that rises in temperature and air pollution in the days before a major storm were the culprits.

The researchers say these thunderstorm-related atmospheric changes are expected to become much more frequent as global temperatures rise, which could eventually strain healthcare systems as more patients seek relief from troubled breathing.

“Anyone with asthma or [chronic obstructive pulmonary disease] who typically has worse symptoms around storms should be sure to take their inhalers as prescribed by their primary care doctor or pulmonologist,” study author Dr. Christopher Worsham, a research fellow, pulmonologist and critical care physician at Harvard Medical School, told Gizmodo. “If their symptoms are not well controlled, they should let their doctor know.”

The researchers analyzed storm data from the National Oceanic and Atmospheric Administration in all counties in the continental U.S. from January 1999 to December 2012, according to the study. They then compared that data with insurance claims and health information from 46.5 million Medicare members older than 65 years with respiratory diseases.

In all, the team identified about 22 million emergency room visits for respiratory issues when thunderstorms were present. They then estimated that approximately 52,000 additional respiratory hospital visits for adults older than 65 occurred in the three or more days surrounding major storms over the 14-year study period.

In the quest to learn why thunderstorms triggered the need for medical attention, the researchers turned to the days patients were turning themselves in.

Emergency room visits peaked before thunderstorms struck, according to the study. Researchers found that pollen didn’t play a major role in the respiratory illnesses because pollen counts didn’t change until after storms passed, when they dropped.

And because pollen is mostly to blame for asthma attacks in younger people with respiratory diseases, the researchers say their study may not generalize to that population.

But what the researchers did find was that temperatures and particulate matter — microscopic particles such as dust, soot and smoke that float in the air — were higher than average before thunderstorms, and declined on the day of and days following them.

The team therefore suggests temperature and air pollution were the “dominant mechanisms” behind the hospitalizations.