Mystery pollen bomb strikes London: Baffled residents complain of tight chests, red eyes, and brain fog - despite the Met Office forecasting low levels

Daily Mail​

06-05-2025

Londoners have complained of a mysterious 'pollen bomb' across the city's parks over the bank holiday weekend.
Despite the Met Office forecasting low pollen levels, park-goers said they were left 'choking' on thick clouds of pollen.
On social media, residents complained of tight chests, red eyes, and brain fog as they walked through the parks.
In a video posted to TikTok, one user said: 'I felt like I had literal shards of pollen going into my eyes. Please tell me I'm not the only one because that was scary and I need to know how to prepare for the rest of summer if it's going to be like this.'
Conditions were so bad that even those who normally don't suffer from hay fever were even affected.
One commenter wrote: 'I thought it was just me. I've never had an issue with hay fever until this weekend.'
Piers Morgan was one of those affected by the pollen bomb, tweeting: 'Anyone else got shocking hay fever in London today?
'Even trusty Fexofenadine barely touching the wheezing, sneezy, fog-brained sides..'
Piers Morgan was one of those affected by the pollen bomb, tweeting: 'Anyone else got shocking hay fever in London today?'
One TikTok user described the situation in London Fields, a park in Hackney, as a 'pollen tsunami'.
The user said that the pollen levels were so high that they were struggling to see and having difficulty breathing while in the park.
This poster wasn't alone, as social media has been flooded with similar accounts.
In a video posted to TikTok, another Londoner asked: 'What is going on in London with the pollen?
'Every time when you go outside, especially to the park, it feels like you're choking even though you don't have hay fever.'
This user said the clouds of pollen were so thick that they had left a visible residue on their clothing and hair, adding that even their dog was coughing.
However, with the Met Office only forecasting 'low' pollen levels, some residents were left confused as to what was causing their sudden reaction.
One TikTok user said: 'Is there something going on in London air today? Because I don't know what it is but stuff keeps on going into my eyes and I've seen it happening to other people too.'
The user added: 'There's stuff in the air today and it's flying about.'
The 'pollen count' literally predicts the amount of pollen grains per cubic metre of air.
The Met Office predicts the upcoming pollen count by combining measurements of pollen in the air with predicted weather patterns to work out how the pollen will spread.
What is considered a high pollen count varies depending on the type of plant, but symptoms typically emerge around 50 particles per cubic metre.
However, the Met Office's forecast doesn't offer the kind of information that would have alerted Londoners to the 'pollen bomb' exploding in the capital's parks.
Yolanda Clewlow, the Met Office's UK Pollen Forecast Manager, told MailOnline: 'Currently, our forecasts are region-specific and thus don't necessarily reflect very local details such as local parks in London.'
Additionally, the 'visible' types of pollen, which many social media users reported seeing falling from trees, don't typically cause allergies and aren't considered in the Met Office forecast.
According to Ms Clewlow, the extreme levels of pollen around certain parks were due to the weather and trees in bloom at this time of year.
She says: 'We are currently in tree pollen season and are at the tail end of both oak and plane pollen seasons.
'However, there are a lot of plane trees in London and these are currently in season and may be contributing to the allergy symptoms that are being experienced in London.'
The Kleenex 'Your Pollen Pal' forecast predicts that pollen counts for birch will reach 250 particles per metre, while oak pollen levels will reach 126 particles per metre.
For reference, the Met Office considers a birch pollen count between 81 and 200 as high.
In 2017, a team of Polish researchers showed that these species can cause particularly high pollen counts when planted in urban parks.
The researchers found that oak and birch trees produced more pollen when they were isolated than when they were planted in groups.
This means London's parks, which are typically dotted with individual trees, could have a much greater pollen potential than rural areas.
Over the weekend, these seasonal factors combined with the weather conditions to create a perfect storm for pollen.
Ms Clewlow says: 'The weather so far this spring has been ideal for tree pollen being released and in addition, the low rainfall has meant pollen hasn't been washed out of the atmosphere.'
According to the Met Office, humid, windy days allow pollen to spread further.
Likewise, days with high amounts of sunshine typically lead to more pollen being released in the early evening.
In London on Monday, humidity peaked at over 80 per cent while consistent winds of 16 miles per hour helped the pollen spread around the parks.
Likewise, research has shown that warmer temperatures due to climate change are causing more intense peaks of birch pollen season and starting the oak pollen season earlier.
Studies have also shown that city-dwellers experience significantly higher symptom severity and longer symptom duration than people in rural areas when exposed to the same levels of pollen.
Ms Clewlow adds: 'Poor air quality can also exacerbate allergy symptoms.'
Thankfully, Londoners will be glad to know that the UK is now moving out of the pollen season for both oak and birch, so the issue should abate over the coming weeks.
Why DO some people suddenly develop hay fever out of the blue?
For most hay fever sufferers, symptoms begin in childhood and persist for the rest of their lives.
But some people appear to develop the condition suddenly and without any obvious reason, even well into their adult life.
No-one knows exactly why hay fever can appear out of the blue but there are a number of theories.
One is that they experienced very mild symptoms as a child that they did not notice.
Another is the 'hygiene hypothesis', that our bodies are weaker as we age because we aren't exposed to as many infections as children.
Research has indicated that youngsters who grow up on farms with regular contact with animals are less likely to develop allergies later in life.
Another possibility is that sudden hay fever happens when the body is exposed to new surroundings - like moving from the city to the countryside, where there is usually more pollen.
But the same might also be true in people moving from rural to urban areas, with some evidence that pollution can exacerbate hay fever.
A weakening of the immune system could also be a trigger.
A bad infection, illness or traumatic emotional event may leave the body vulnerable to normally harmless allergens.
Between 15 and 20 per cent of people in the UK are thought to be affected, with the numbers being even higher among teenagers and symptoms typically peaking in people's 20s.