When an asbestos claim is made against a number of former employers for exposure to a level of asbestos at each workplace it can be difficult to apportion the precise amount of the blame. Which particular workplace exposure can be shown to be the original cause of an asbestos-related disease, most commonly mesothelioma, and which workplace “materially contributed to increasing the risk” of developing the disease?

While settlements can and often are reached between several former employers who agree to award a proportion of damages to a claimant, there can be instances where the outcome is contested and an appeal is successful.

Exposed to asbestos over the course of working life

The latest example where it was claimed that every defendant who wrongfully exposed a victim to asbestos should be “held jointly and severally liable for full damages” has been dismissed on appeal. The 75 year old victim, who was exposed to asbestos over the course of his working life, was employed by the six defendants between 1961 and 1974.

Victims of mesothelioma and their families are often able to recover 100 per cent of compensation awarded from just one defendant who was shown to have made a material contribution to the risk of the development of the condition. However, those defendants who are diagnosed with asbestos related lung cancer, which is different from cancer of the lung linings, can face robust opposition in court from former employers and their insurers determined to dispute a level of responsibility, and subsequently, liability to pay mesothelioma compensation.

Actual medical evidence of fibre dosage levels

In asbestos related lung cancer cases, a claimant can often be required to provide actual medical evidence of fibre dosage levels measured over the course of the relevant time period, which can be related to distinct employment periods at different workplaces.

In the present case, there was a need to show that the victim had been exposed to sufficient quantities of asbestos to have more than doubled the risk of developing the disease. Medical experts agreed that the evidence obtained did clearly show that a sufficient, sustained exposure to asbestos more than doubled the risk. The evidence also gave a breakdown of the exposure caused by individual defendants, which ranged from 2.5 per cent to 10.1 per cent of total exposure.

Unable to prove that any one defendant was responsible

As a result, the defendants argued that, “it could not be said that any one defendant had actually caused the cancer” as the medical evidence did not show where the specific individual cause was directly related to an individual defendant. Instead the extent of the liability has to be based on the increased material risk of the cancer. Therefore, each defendant was liable only in proportion to their individual, separate contribution to the risk.

The judge found in the defendants’ favour stating that ,“lung cancer and mesothelioma are legally indistinguishable” as well as agreeing with the defendant’s argument that the claimant was unable to prove that any one defendant was responsible for causing the “actual injury”, i.e. asbestos lung cancer. Therefore, in contrast with the approach taken in mesothelioma cases, compensation would have to be apportioned accordingly.

Exposure amounted to less than 50 per cent

Furthermore, liability to pay compensation by individual defendants will be based on whether exposure amounted to less than 50 per cent of their overall contribution. A claimant could recover 100 per cent of compensation if they are able to establish that an individual defendant was responsible for over 50 per cent of total asbestos exposure dosage.

The ruling must be seen as a significant blow to all those with asbestos-related lung cancer who seek to establish liability. Mesothelioma sufferers can usually succeed in their claim as it often depends on showing ‘on the balance of probabilities’ that it was likely that contracting the fatal disease was due to a level exposure to asbestos during the period when the claimant was employed at the company compared to any exposure levels at any other workplaces during an entire lifetime.