Well worried

The list of modern health anxieties is long, but old-fashioned smoking and hitting the bottle are the real worries.

- Nicky Pellegrino

Fluoride in the water supply, electromagnetic radiation, toxic chemicals in our homes, genetically modified food, vaccinations, air pollution - many people are concerned about threats real and potential - that modern life may pose to their health. This isn't a new phenomenon. New technologies have long been a source of anxiety.

When AM radio was first introduced, for instance, there was concern that invisible waves were making people sick. And in the 1980s, there were fears that looking at a computer screen for long periods increased a woman's chance of miscarriage.

"There has always been suspicion about modernity and things changing and the negative effects that might have," says Keith Petrie, a professor of psychological medicine at the University of Auckland.

Petrie started studying modern health worries more than 20 years ago, well before the internet was such an influence in amplifying them. Back then, his surveys of New Zealanders concluded contaminated water was the most common fear, with traffic fumes, antibiotics in food and bacteria in air-conditioning systems also very much on people's minds. He found that those with higher modern health worries were more likely to experience symptoms and seek medical care.

Petrie's interest in this area of research was sparked one day while chatting over lunch with members of a tennis team he belonged to. "I was surprised how many of them thought their health was influenced by these environmental factors. They had read about it in the media and were genuinely concerned. And I thought it was something health psychologists hadn't picked up on before." In 2002, an aerial-spraying programme to eradicate the painted apple moth in areas of West Auckland provided Petrie with an opportunity.