People are worrying themselves sick because important quality-of-life issues have been ignored, health protection experts said yesterday.

The NHS cost of treating ill-health caused by disease and injury is far outweighed by the costs to society generally, Health Protection Agency officials said.

The agency's annual conference was told more attention needed to be focused on tackling the causes of anxiety that were making the nation ill, such as environmental issues like landfill sites.

The most deprived sections of society were worst affected, delegates heard

The conference, at the University of Warwick, learned about progress on a report detailing the burden of disease which is due to be published later in the year.

It found that while costs could be put on what the NHS spends on treating infectious disease and dealing with poisonings and injuries, it was much more difficult to estimate the cost to society as a whole.

This was in terms of people taking time off work sick, becoming ill due to depression and suffering poorer quality of life.

Dr Elaine Farmery, who is among those working on the report, said: "Whenever we talk about the cost of hundreds of millions to the NHS we can talk in billions for society."

Environmental issues such landfill sites, industrial pollution and mobile phone masts had all caused widespread public concern. But it was more difficult to measure the burden of such worry as the actual health impact of these things remained unclear.

Prof Stephen Palmer, from the HPA, said: "Whenever a nurse jabs herself with a needle she worries about getting Hepatitis.

"The chances of her getting that are very small. The worry is huge. The same goes for people living near a landfill site. People are measurably worrying themselves ill.

"There is a community-wide anxiety and depression as a result of the fear."

Prof Pat Troop, HPA chief executive, said the agency wanted to measure the burden of well-known issues, such as infectious disease, but then try to identify areas which had not traditionally been focused on.

"If you can count something easily then people will sta working on it.

"But in other areas, such in environmental work, it very hard to get a measure o exposure and on long-ter problems and chron problems.

"It's difficult to measure, if you can't measure an quantify it, it's harder ther fore to give it a priority," Pr Troop said.