Back in the late 1980s, the 'hygiene hypothesis' was put forward to explain the epidemic of allergies that were affecting children. The idea was that the lack of childhood infections (caused by too much vaccination and too many antibiotics) was damaging children's well-being.

As a result, children's immune systems overreacted when exposed to otherwise harmless allergens. This hypothesis is now being replaced by a new theory that argues that while a lack of early childhood infections may have an influence, it is the lack of exposure to common microbes that is really the culprit. In other words our houses (and children) are too clean for our (and their) own good. Given that the incidence of allergies is much lower among people who grow up on farms, perhaps in the future we will see 'dirt holidays' where children are exposed to farmyard animals, dirt and filthy water.

Or perhaps you'll be able to buy aerosols of common bugs in the supermarket to spray on kitchen surfaces, baths and children.

Ref: New Scientist (UK), April 2005. 'Love your bugs'. www.newscientist.com

http://nowandnext.com/?action=sector/view&issueId=5&sectorId=10