Pollen breakdown and transmission in thunderstorms could trigger asthma attacks in patients with allergy, according to a leading respiratory expert.
Professor Isabella Annesi-Maesano warned that being out in an electric storm could be dangerous for those with pollen nasal allergy that have never previously experienced an asthma exacerbation.
“People with pollen nasal allergies may inhale a high concentration of the pollen fragments”
The academic believes that climate change and air pollution may be causing the increasing break-up and distribution of pollen micro-particles that can travel deeper into the lungs, triggering an attack.
According to Professor Annesi-Maesano, thunderstorms are a catalyst for the process and there is growing evidence for the occurrence of severe asthma epidemics during storms in the pollen season.
She said pollution and climate change were having a major impact on chemical and biological factors in the environment, including a lengthening of the pollen season and the breakdown of pollen.
A large asthma outbreak was recorded in 1994 that coincided with a heavy thunderstorm. A large increase in the number of visits for asthma to accident and emergency departments in London and the South West was observed, as described in the journal Clinical and Experiment Allergy.
Many of those who experienced an asthma attack during the outbreak were not known to have the condition or to be sensitised to pollen and had been affected only by seasonal rhinitis previously.
“These risks are only likely to increase as climate change continues to cause further extreme weather changes”
But the most severe episode ever recorded was in Australia in November 2016, when around 8,500 people sought hospital treatment after thunderstorms swept across Melbourne. Nine patients died.
Professor Annesi-Maesano, from the National Institutes of Health and the Pierre Louis Institute of Epidemiology and Public Health in Paris, will explain her theory today at the British Thoracic Society’s 2017 Winter Meeting in London.
The academic will highlight that air pollution may be causing the external membrane of pollen to become more fragile and break, meaning allergens can leave more easily.
These smaller particles have the ability to travel deeper into the lower airways, causing asthma in those susceptible to pollen nasal allergy, she will tell the audience of respiratory specialists.
In addition, she will note that air pollution itself induces airway inflammation and can add to the damaging effects of these sub particles.
During a thunderstorm, dry uplifts of air can draw whole pollens into the high humidity at the cloud base where particles may rupture due to the electricity in the storm, and then cold downdrafts carry small pollen fragments to ground level where they are spread, she will say.
Consequently, there is an unusually high level of allergens in the air at ground level, according to Professor Annesi-Maesano.
Speaking ahead of the event, she said: “The effects of climate change and pollution pose an increasing threat to our health – and our lungs are on the front line.
Thunderstorms during pollen season may trigger asthma attacks
“As an example, increased severe wind storms are carrying pollen in great quantity and over long distances, while at the beginning of thunderstorms the outer membranes of the pollen disrupts, releasing tiny particles into the atmosphere, that contribute to ‘thunderstorm asthma’,” she said.
“This can be very dangerous for people with pollen nasal allergy that have never experienced asthma attacks and don’t know how to manage them,” said Professor Annesi-Maesano.
“During the first 20-30 minutes of a thunderstorm, people with pollen nasal allergies may inhale a high concentration of the pollen fragments dispersed into the atmosphere, which in turn by penetrating the airways, can induce asthmatic reactions, often severe,” she said.
She added: “People who are affected by pollen nasal allergy, but don’t have asthma, should also be alerted to the danger of being outdoors at the beginning of a thunderstorm in the pollen season, as such events can cause severe asthma attacks.
“These risks are only likely to increase as climate change continues to cause further extreme weather changes,” she warned.