A new DNA test could help to prove if people have had their health damaged by exposure to toxic chemicals. The test involves taking DNA samples from a healthy person and then exposing it to the chemical in question to see which genes are affected. This is then used as a blueprint against which a claimant DNA can be compared.

If this test had been available when Erin Brockovich famously fought her battle in life, and on the screen, to prove that the people she represented had been exposed to hexavalent chromium her case may have been significantly speeded up or even seen a different outcome. Brockovich's campaign won $333m (£164m) in compensation for the people she represented.

Her legal fight against Pacific Gas & Electric Co inspired a Hollywood film named after her, in which she was played by Julia Roberts (far right).

The new technique is expected to be used in civil cases to confirm or deny exposure to and illnesses caused by harmful substances. It could also dramatically reduce the time it takes to settle cases where miners, industrial workers and others seek compensation for health problems caused by exposure to asbestos, coal dust or other environmental toxins.

More than 3,000 people a year die from asbestos-related diseases in the UK and the numbers are predicted to rise to 10,000 a year by 2020. Many cases involving exposure to chemicals take so long to settle that the claimants die before they get compensation.

Exposure in the workplace has been recognised as a danger since 1955. The health risks have also been extended to the relatives of workers who came into contact with asbestos fibres.

The scientist who helped to develop the test, Bruce Gillis, at the Illinois College of Medicine, said it would allow some people to win cases they might have lost. But he added that others would find themselves with no case because their diseases were not caused by the chemicals to which they were exposed.

(By Thair Shaikh, The Independent, 17/09/2007)