While most people associate thunderstorms with such hazards as flooded basements and slippery roads, for many people with asthma severe weather conditions may trigger an attack. Now, Australian researchers have found that the culprit is the airflow patterns of some thunderstorms, rather than the electrical activity or rain, that is responsible for triggering these weather-associated asthma epidemics. The study was published in the June issue of Thorax.
The researchers identified asthma epidemic days in six towns in southeastern Australia between 1995 and 1998 (by examining hospital admission rates for asthma) and compared airflow patterns occurring on those days and on a random sample of control days. They found that thunderstorms with outflows—downdrafts of cold air containing high concentrations of particles—occurred on 33% of asthma epidemic days vs only 3% of control days.
Stephenson J. Thunderstorms and Asthma. JAMA. 2001;285(22):2847. doi:10.1001/jama.285.22.2847-JWM10005-3-1