Asbestos related lung cancer claims have always been a problem for lawyers. The HSE believes that there are as many instances of asbestos related lung cancer as there are of mesothelioma but claim numbers do not reflect this. Part of the reason are the legal difficulties in making out causation when the claimant has been a smoker for a great part of his life. How do you distinguish the cause of the cancer? Medicine is unable to distinguish between the two possible causes so a claimant can never prove on the balance of probabilities which period of exposure has caused his illness.

There is now an answer, at least for the moment. . The Court of Appeal has held that where there are multiple negligent periods of exposure the correct test is that applied in Fairchild - i.e. did the exposure materially increase the risk of the cancer? If so the defendant is liable but only for his proportion of the total period of exposure.

Given the historic nature of many of these claims it is common for there to be missing defendants or insurers and therefore periods where the claimant would be uncompensated. In mesothelioma cases this inequity was dealt with by the Compensation Act which overturned Barker, making each defendant liable for the whole of the damage. The Act does not extend to lung cancer, however, so claimants will only be able to recover damages where they can find defendants or insurers who are still solvent.

It is difficult to see that this situation will remain for long. The Compensation Act provision was introduced as a pragmatic response to a perceived injustice. It is unlikely that lung cancer victims will be allowed to be disadvantaged in this way before the intervention of Parliament again.

Insurers may be advised to settle such claims quickly whilst they need pay only their proportion of the damages. Claimants may be better advised to wait to see if the law is changed - if this is an option open to them.

The Court of Appeal case is Henegan v Manchester Dry Docks Ltd