In June last year, the UKHSA’s Real-Time Syndrome Surveillance System identified a possible episode of thunderstorm asthma; Increase in people reporting asthma symptoms associated with thunderstorm activity
As spring blooms and as we approach the season for these events, in this British Science Week blog we look at the interplay between weather and our health and how we can use our scientific surveillance systems to respond to future public health.
Thunderstorms, like many types of weather events, can be dramatic, illuminating the sky and inspiring folklore, legends and songs. Little is known about the effects of thunderstorms on health.
Since it was first officially registered in 1983, there have been some instances where lightning activity has been associated with an increase in people reporting asthma symptoms and seeking medical advice for their respiratory problems. These episodes are called ‘thunderstorm asthma’.
We do not fully understand why these events cause respiratory problems and make it very difficult to predict when they may occur.
However, air flow in a thunderstorm system is considered important. Thunderstorms are formed when the warm humid air on the surface of the earth is much lower than the cooler air in the atmosphere. Warm air rises rapidly (known as up-draft) which causes cold air to flow towards the soil (known as down-draft). As the warm air rises, it cools and the moisture condenses into clouds and water molecules.
As cold air (down-draft) falls to the ground, increasing pressure creates a strong cross wind on the surface. This surface air flows through grasses and plants, picking up pollen grains and fungus spores (small biological particles by which the fungus reproduces), which are carried in the air currents. More pollen is thought to be in the atmosphere than you expected during a thunderstorm.
It is then assumed that pollen and / or spores are caught in the up-draft and dragged into the cloud and storm system. Excess moisture in the clouds enters the pollen grains and spores of the fungus causing them to break down into smaller grains and / or other particles. The rain then carries tiny particles from the clouds to the soil level where micro-particles can penetrate deep into the lungs, causing shortness of breath.
In addition to the described weather factors, there are environmental and individual factors associated with these episodes. Environmental factors include relatively high levels of pollen and / or fungus seeds, usually after a warm and humid day.
Who is affected by thunderstorms asthma?
While everyone may be at risk for thunderstorms, previous events indicate that young adults (under 30) may be particularly affected. Although the data is somewhat limited, there is some evidence that certain people have a higher risk of developing thunderstorms. These include:
- Asthma has been diagnosed before – especially in those who have very little or no control over their asthma
- Asthma, but it was not officially diagnosed during the thunderstorm episode
- Seasonal allergic rhinitis (hay fever)
Past experience of thunderstorm asthma
The largest typhoon recorded worldwide occurred in Melbourne, Australia on Monday the 21st.St. November 2016. It was the first hot day of the year where temperatures ranged from high to mid-30C after a wet and warm spring.
A strong thunderstorm warning was issued around noon. The storm moved west from the state of Victoria, with the epicenter approaching the Melbourne area around 17:00 hours.
The number of patients complaining of shortness of breath with asthma-related symptoms has increased in the healthcare sector since about 18:00 hours. Ambulance services, hospitals and emergency departments, general healthcare providers all felt the pressure of increasing service use, which continued until the next morning.
Ambulance calls increased 73% of call outs; Emergency department representation increased by 58%, the number of people present with respiratory problems increased by 672%. The number of asthma-related hospital admissions has increased by 992%, resulting in 30 people being admitted to the intensive care unit. After searching for a corona, 10 deaths were associated with the incident.
In England, the first recorded episode of thunderstorm asthma occurred in Birmingham in July 1983 and there have been many recorded incidents across the country since then.
Most recently, in June last year (2021) a potential episode of thunderstorm asthma was identified by the UKHSA’s Real-Time Syndrome Surveillance System.
Syndrome monitoring is a tool we use to gather information about the health of the general public and to see in real time (every day) whether there is a disease that is following an abnormal trend, such as a sudden increase in an unexpected time of year. . May is generally cold and wet in England, where June is observed to last longer than average temperatures.
Pollen levels were consistently high or very high in all parts of England at that time. On the 17thM In June, severe thunderstorms were forecast across southeastern and eastern England as warmer weather breaks and a hurricane moves south-west, leading to a yellow (‘conscious’) thunderstorm warning issued by the Met Office.
During this time, we have noticed a large increase in the index for asthma and shortness of breath across a number of UKHSA syndrome monitoring systems, including the NHS 111 call and the presence of the emergency department.
Spikes were most noticeable in patients aged 15–45 years and observed throughout London and the south-east and east of England. This is one of the most significant cases detected by such a syndromatic system.
For example, the emergency department attendance for asthma on June 17 increased by 560% compared to the average number of daily attendances for the previous 4 weeks. Further details are available through the PHE Real-Time Syndrome Surveillance Report for the week of this event or the published scientific report describing the results.
Why is thunderstorm asthma a public health problem in England?
Asthma and hay fever are very common conditions in the UK with asthma and lung statistics suggesting that 1 in 11 children and 1 in 12 adults, (equivalent to 5.1 million people) are currently receiving treatment for asthma in the UK.
The British Lung Foundation estimates that 8 million people (12% of the UK population) have asthma. Allergy UK recommends that 10-30% of adults and 40% of children in the UK suffer from allergic hay fever. There is therefore a significant susceptible population of otherwise potentially healthy individuals who may be affected by thunderstorms.
Climate change may also increase the likelihood of such an event. Although there is limited evidence that climate change will cause more intense and frequent thunderstorms, there is good evidence that earlier and longer growing seasons can lead to higher concentrations of aeroallergens such as grass pollen. But it does not stop there; Increased CO2 Concentration has been associated with increased spore count of allergenic fungi (Alternaria Alternata) And increase atmospheric pollen.
Therefore, the combination of extended growth periods with favorable weather, and high levels of CO2 Thunderstorms may increase the risk of future asthma events from human activity. Also, there is evidence that the interaction of pollen and air pollution could potentially increase the allergic reaction capacity of susceptible individuals.
What are we doing about thunderstorm asthma?
In response to potential health risks, UKHSA is working with experts from all agencies, the Met Office and academia.
This work will include the development and publication of scientific evidence on the role of a range of weather conditions on the health effects observed during these events. The results of this work will be used to determine what risks can be mitigated to address health protection and future public health responses.
If you have already been diagnosed with asthma, the NHS has helpful advice on steps you can take to manage your condition. Asthma and Lungs UK also have weather-related data as asthma triggers.
As our climate warms and changes in the natural system continue, it is possible that thunderstorm episodes may occur more frequently in the coming years.
This is why it is vital that we increase our understanding of this event, so that these episodes can be better anticipated, and effective health care measures are created to keep the thunderstorms, the dramas they bring, the inspiration for stories and legends, and No. The story of the impact of real-world public health in England.