#2332 - Ministry Of Defence V Ab And Others - Tort Law

Ministry of Defence v AB and others [2010] EWCA Civ 1317

Court of Appeal

Facts

In 1952 the British Government detonated some nuclear and fusion bombs above the Pacific, with the result that C were exposed to radioactive fallout. C were potentially exposed to fallout at different places at different times, and were exposed for differing lengths of time. A study suggested that C had more chromosal aberrations than normal, which suggested they had been exposed to ionising radiation, but there was no link with this to diseases being suffered.

Held Smith LJ

• It is common ground that in tort, causation must usually be demonstrated by evidence from which it can be concluded or inferred that, but for the tort, C would probably not have suffered the injury complained of.

  • Its application can give rise to difficulty in claims in which there is more than one potential cause for the condition complained of and only one of those potential causes arises from the negligence of the defendant.

    • It is common ground that all the conditions of which the claimants complain have several different possible causes besides radiation

Bonnington

• The decision of the House of Lords in Bonnington amounted to a modification of the 'but for' rule of causation because C recovered damages for the harm caused by all the dust, not just the tortious component.

  • At no stage in that case was it suggested that the damages should be apportioned as between the effect of the tortious and non-tortious components. If that had been suggested, the damages would probably have been apportioned.

    • C would have recovered damages for only the harm caused by the tort and there would have been no need for any modification of the 'but for' rule.

• This type of modification of the 'but for' rule is still available where the negligent and non-negligent causative components have both contributed to the disease (as opposed to the risk of the disease) and it is not possible to apportion the harm caused and therefore the damages.

  • This method of proving causation (by showing that the tort made a material contribution to the condition or disease) is only available where the severity of the disease is related to the amount of exposure;

    • further exposure to the noxious substance in question is capable of making the condition worse.

Fairchild

• Under the Fairchild exception, it will be sufficient for C to show that the tort has materially increased the risk that he will develop the condition complained of.

  • That exception is of very narrow application based upon the particular facts of the case which involved the disease of mesothelioma.

    • The C’s difficulty was that they could not show whose asbestos had caused their disease. They could not rely on Bonnington because mesothelioma is an indivisible condition.

      • All the claimants could say was that each employer's exposure had materially increased the risk that they would develop the disease – this was regarded as sufficient.

      • MOD submits that the reason why the House had been prepared to allow the exception at all was because asbestos was the only known cause of mesothelioma. There was no other different potential cause.

        • The exception would not apply where, as here, there was more than one different potential cause. In such cases Wilsher would apply.

Judgement

• As far as cancer is concerned, C cannot rely on proving that the radiation exposure has made a material contribution to the disease, as in Bailey and Bonnington Castings.

  • This principle applies only where the disease or condition is 'divisible' so that an increased dose of the harmful agent worsens the disease.

    • In Bonnington, the claim succeeded because the tortious exposure to silica dust had materially aggravated (to an unknown degree) the pneumoconiosis which the claimant might well have developed in any event as the result of non-tortious exposure to the same type of dust.

      • The tort did not increase the risk of harm; it increased the actual harm.

    • Similarly in Bailey, the tort (a failure of medical care) increased the claimant's physical weakness. She would have been quite weak in any event as the result of a condition she had developed naturally.

      • No one could say how great a...