Hay fever maps: Which areas to avoid where the pollen concentrations are highest

Hay fever, an allergic reaction to pollen, is estimated to affect up to one in five people

The maps show where there are high concentrations of pollen from trees and plants including alder, ash, birch, dock and mugwort (The Met Office)

Hay fever sufferers whose symptoms are triggered by grass pollen may want to avoid a holiday in Wales this summer. But those who find spores released by hazel trees set off sneezing, itchy red eyes and a runny nose should head to Yorkshire as soon as possible.

A new series of maps show where in Britain has the highest concentration of trees and plants that produce allergy-causing pollen.

Alder, dock and ash are among the trees whose location is shown in the maps, created by academics at the University of Exeter’s Medical School.

The detailed diagrams show birch and hazel trees are predominantly found in the South-east of England, while the mugwort plant tends to grow along the eastern coast of Great Britain.

Hay fever is estimated to affect up to one in five people, with grass pollen one of the worst offenders for the allergy.

Nettle plants appear to mainly be found in cities, with clusters around London, Birmingham, Liverpool, Manchester, Leeds and Glasgow among others.

Grass pollen hotspots include much of Wales and national parks such as Exmoor, the Peak District, the Lake District and the Yorkshire Dales, as well as many areas in Scotland.

The researchers, working in collaboration with the Met Office, said they hoped the maps could help people with severe cases of hay fever or asthma aggravated by pollen choose where to live or avoid when pollen counts are high.

More detailed maps have also been produced for London. The capital’s hay fever sufferers may already avoid major green spaces such as Hampstead Heath or Richmond Park, but a move to Wembley in north-west London, which appears to have low levels of most allergy-causing plants, would ease their symptoms.

According to the Exeter researchers, around 80 per cent of people with asthma also have a pollen allergy and the UK has one of the world’s highest levels of diagnosed asthma, with around 10 per cent of the adult population affected by the condition.

Birch trees are more commonly found in London’s leafy suburbs (University of Exeter)

“We hope that these maps will contribute to ongoing research that aims to better determine when plants pollenate, allowing us with time to provide better warning to allergy and asthma sufferers to enable them to better manage their disease,” said epidemiologist and toxicologist Dr Nicholas Osborne. “In the future, more people will know what species they are allergic to.”

A recent study by Imperial College London found that hay fever sufferers could “suppress” the condition by having treatment for three years continuously.

While a three-year course of treatment with pollen pills or injections was shown to markedly lessen symptoms “for several years”, two years of treatment did not bring the same benefits.