Parents believe pollution is a greater threat to their children's health than genetically modified food, a study shows.

The research by Norwich Union Healthcare found that one-third of parents rated pollution as top children's health danger, followed by junk food, lack of exercise, food additives, images of the perfect body portrayed by the media, and genetically modified foods.

To fight pollution-generated illnesses such as asthma, NU Healthcare has produced a booklet called Playground Plagues.