Residents may receive a higher dose of pollen

Spanish scientists discovered residents of tower blocks were much more likely to suffer grass pollen allergies than those living in houses in the countryside.

The findings will surprise many hayfever sufferers, as the condition is commonly associated with rural settings rather than inner-city buildings.

Experts at the Hospital Rio Hortega in Valladolid, northern Spain, investigated the link between where people live and hayfever because, they said, little research has been done on the "vertical distribution" of pollen and hay fever symptoms.

They studied 17,171 patients who either lived in the city of Valladolid or surrounding towns and villages.

If the pollen is falling and you are in a high-rise building with the window open, then you're going to get it first Julie Corden, Midlands Asthma and Allergy Research Association

The results, presented at the annual meeting of the European Academy of Allergology and Clinical Immunology in Paris, showed the risk of pollen sensitisation was higher in residents who lived in tower blocks than those living at ground level in the city.

The risks were still higher when they were compared with people whose homes were in villages in the local countryside.

Dr Alicia Armentia, who led the study, said: "On the basis of our local investigations, natural pollen sensitisation appears to increase with the height of where the patient lived."

High danger

Julie Corden, a hayfever expert at the charity Midlands Asthma and Allergy Research Association, said the findings fit with what's known about the distribution of pollen in the atmosphere.

"Pollen is released in the morning and then rises up into the upper atmosphere as the temperatures get warmer.

"Then, as the air cools in the evening, it starts to come down again. Usually the hours of 7pm to 10pm are when pollen counts are at their highest level.

"If the pollen is falling and you are in a high-rise building with the window open, then you're going to get it first and it will be at a higher level."