LETTER TO THE EDITOR Dear Editor,Hay fever is a form of allergic rhinitis caused by pollen released by trees, grass and plants, or by spores, discharged by mould and fungi. 1 The prevalence of hay fever in children has more than trebled since the 1960s, 2 and it has been estimated that about 25% of the United Kingdom population currently suffers from the condition. 3 Furthermore, it has been predicted that this will increase to 39% of the population by 2030, largely due to increasing urbanisation, and the effect of pollution on hay fever levels.Hay fever has both a direct and indirect effect on public health. Research published by the National Pollen and Aerobiology Research Unit (NPARU) 4 found that 78% of hay fever sufferers believed that the condition had a detrimental impact on their quality of life. In terms of work-life, individuals reported that they could only operate at two-thirds of their normal productivity when their symptoms were at their worst. As these severe symptoms occurred for an average of 15 working days per annum, this has a significant impact on economic development. Furthermore, 35% of those surveyed reported that hay fever symptoms affected their social activities, with one-quarter socialising less often with family and friends when they had hay fever. Consequently, there is a large financial cost resulting both from medical treatment and the loss of school and working days; in 2004, this was estimated for Europe at €3.7 billion per annum. 5 Apart from the medical treatment of hay fever, prevention strategies have largely consisted of recommending that individuals shorten the time that they spend in outdoor air in periods during which the pollen concentration is at its highest. 6 However, this relies on accurate pollen monitoring and forecasting; it also has the major disadvantage of restricting social activities for hay fever sufferers. Throughout history, humans have altered their physical environment to better suit their needs. Perhaps, therefore, it is time to seriously consider environmental modification to reduce the 'allergenic load' and therefore the burden of hay fever in the population, coupled with more research on the impact of theseThe public health impact of hay fever: is it time to look at prevention through environmental modification?The March 2014 CPD paper was: 'Addressing the inverse care law: the role of community paediatric services' Answers 1c, 2b, 3d, 4bThe July 2014 issue will be the next CPD issue of the journal