Supreme Court Hands Down Landmark Mesothelioma Ruling

Posted: 11th March 2011

The Supreme Court has handed down its judgment in two cases concerning women who died of mesothelioma. In each case, the employer was the sole known source of occupational exposure to asbestos dust and the extent of exposure was found to be very small.
Mrs Enid Costello was exposed to asbestos whilst working for Greif (UK) Ltd. at its factory in Ellesmere Port. Mrs Dianne Willmore was exposed to the substance whilst a pupil at Bowring Comprehensive School in Merseyside.
The current state of knowledge regarding mesothelioma is that it is always, or almost always, caused by inhalation of asbestos fibres. Because medical science cannot, as yet, pinpoint which asbestos fibre or fibres caused a person to develop the disease, the conventional causation test – whereby a claimant must show that it is more likely than not that the harm suffered was caused by the defendant’s breach – does not apply in mesothelioma cases. The rules are relaxed in such cases so that the test for liability is whether or not the claimant has been wrongfully exposed to asbestos, thus creating a ‘material increase in risk’ of them developing the disease. Where a defendant is found liable in a mesothelioma case, they are liable for the whole of the damage caused to the victim and, if anyone else is held responsible, they are held to be jointly and severally liable.
Although there is no known minimum level of exposure to asbestos below which there in no risk of developing mesothelioma, the defendants argued that the relaxation of the rules did not apply in cases where there was only one defendant and the level of the exposure to asbestos was very low. They sought to establish a threshold of exposure that would apply in single exposure cases by applying the ‘doubles the risk’ test – i.e. occupational exposure is not material unless it more than doubles the amount of environmental exposure – i.e. exposure to asbestos in the atmosphere.
The Supreme Court dismissed the appeals. The Law Lords found that there was no justification for adopting the ‘doubles the risk’ test as a benchmark of what constitutes a ‘material risk’ in such cases. There are special features associated with mesothelioma which justify the unique ruling and the current test for causation should stand. Were there to be advances in medical knowledge of mesothelioma in future, however, the courts might then revert to the conventional causation test if appropriate.
If you have concerns about the legal aspects of your health and safety policy, contact us.
For information on the control of exposure to asbestos in the workplace, see