Introduction An increasing body of evidence shows the occurrence of asthma epidemics, sometimes also severe, during thunderstorms in the pollen season, in various geographical zones. Thunderstorms have been linked to asthma epidemics and there are descriptions of asthma outbreaks associated with thunderstorms in several cities, prevalently Australia (Melbourne) and Europe (in UK Birmingham and London, and in Italy in Naples). Considering this background it is important to promote the dissemination of these evidence also in occupational setting.

Methods Analysis of literature was performed on asthma, thunderstorm, occupational health. Description of these events in the Mediterranean area was also investigated.

Results Asthma outbreaks associated with thunderstorms occurred in several cities as London (24/25 June 1994) and Melbourne (21 November 2016). In the first outbreak 640 patients with asthma or other airway diseases attended London hospitals (nearly 10 times the usual number); in Melbourne, hospitals were swamped with emergency patients affected by severe asthma attacks (more than 8500 patients across Monday night and Tuesday and 8 died). The frequency of thunderstorms had recently increased in some geographical areas, particularly in temperate and subtropical climates. Research has shown that thunderstorms are expected to become more severe as the climate changes.

Conclusion Thunderstorms have been linked to asthma epidemics, especially during the pollen seasons. There is evidence that hat under wet conditions or during thunderstorms, pollen grains, release into the atmosphere their content that can reach lower airways inducing asthma reactions.

All individuals affected by pollen allergy should be alerted to the danger of being outdoors during a thunderstorm in the pollen season. Outdoor workers should be informed; training should be addressed in order to promote collective and individual control and preventive measures. Being the Mediterranean area subject to thunderstorm episodes it is necessary the activation to specific planning to respond at these events.