barker (Respondent) v. Corus (UK) plc (Appellants) (formerly barker (Respondent) v. Saint Gobain Pipelines plc (Appellants) and others (Conjoined Appeals)
13. The House treated McGhee as an application avant la lettre of the Fairchild exception. This came as a surprise to some commentators (see, for example, Tony Weir, Making it More Likely v Making it Happen  CLJ 519) because Lord Bridge of Harwich, speaking for the House in Wilsher v Essex Area Health Authority  AC 1074, 1090D, had said that McGhee demonstrated no more than a "robust and pragmatic" (ie in the teeth of the evidence) inference from the primary facts. In Fairchild, however, only Lord Hutton was willing to accept this interpretation. McGhee must therefore be accepted as an approved application of the Fairchild exception.
14. For present purposes, the importance of McGhee is that it was a case in which there had been two possible causes of the pursuer's dermatitis: the brick dust which adhered to his skin while he was working in the brick kilns and the dust which continued to adhere to his skin while he was on his way home. Both risks had been created by his work for the Coal Board but the exposure while working in the kilns was not alleged to involve any breach of duty. The only breach was the failure to provide showers so that he could wash off the dust before cycling home. So one source of risk was tortious but the other was not. The House decided that the Fairchild exception allowed him to recover damages although he could not prove that the persistence of dust after he had left work was more likely to have caused the dermatitis than its original presence on his body while he was working.
15. It was in order to accommodate this case that Lord Rodger in Fairchild, at p 119, para 116, accepted that the exception could apply "where, as in McGhee, the other possible source of the injury is a similar, but lawful, act or omission of the same defendant." Likewise, Mr Stuart-Smith QC, who appeared for the appellants, did not insist that all sources of risk should have been tortious. He allowed for what he called the "McGhee extension" where the risk was created by a similar but lawful act or omission of the same defendant or another tortfeasor.
16. It seems to me, however, as it did to Moses J, that once one accepts that the exception can operate even though not all the potential causes of damage were tortious, there is no logic in requiring that a non-tortious source of risk should have been created by someone who was also a tortfeasor. Suppose, for the sake of an example, that 1962 was the date upon which it became negligent not to take precautions to protect employees against exposure to asbestos. An employee has worked for the same employer between 1955 and 1980. In 2002 he develops mesothelioma. This would plainly fall within McGhee; the employee has been subjected to both non-tortious and tortious exposure by the same employer but cannot prove which period of exposure caused his disease. Suppose, however, that in 1962 the employer had sold the business to someone else, so that the original employer was responsible only for the non-tortious exposure and his successor only for the tortious exposure. It would not be very creditable to the law to draw a distinction between these two cases, so that the employee's right of action depended upon whether the 1962 sale had been of the business or the shares in the company which employed him.
17. It should not therefore matter whether the person who caused the non-tortious exposure happened also to have caused a tortious exposure. The purpose of the Fairchild exception is to provide a cause of action against a defendant who has materially increased the risk that the claimant will suffer damage and may have caused that damage, but cannot be proved to have done so because it is impossible to show, on a balance of probability, that some other exposure to the same risk may not have caused it instead. For this purpose, it should be irrelevant whether the other exposure was tortious or non-tortious, by natural causes or human agency or by the claimant himself. These distinctions may be relevant to whether and to whom responsibility can also be attributed, but from the point of view of satisfying the requirement of a sufficient causal link between the defendant's conduct and the claimant's injury, they should not matter. On this point I am therefore in agreement with Moses J and the Court of Appeal.
18. If the Fairchild exception does not require that all the potential causes of the injury should be tortious, what are the conditions which mark out its limits? For this purpose, it is necessary to examine the way in which the House distinguished Wilsher v Essex Area Health Authority  AC 1074. Again, the facts are too familiar to need recitation. It had certain features in common with McGhee and Fairchild: first, the excessive oxygen which the negligent doctor had allowed to circulate in the baby's blood had increased the likelihood that he would suffer retrolental fibroplasia ("RLF") and might have caused it. Secondly, medical science could not establish whether the excessive oxygen or some other possible source of risk was more likely than not to have been the cause. Thirdly, as in McGhee (but not in Fairchild) the other sources of risk were not created by any breach of duty. These similarities were sufficient for a majority of the Court of Appeal to hold that the principle in McGhee was applicable and the plaintiff entitled to recover. But the decision was reversed by the House of Lords on, as it seems to me, two grounds. The first, which I have already discussed, was that McGhee laid down no principle. It only exemplified a robust handling of the facts. This explanation was rejected by a majority of the House in Fairchild. The second ground of decision was by way of adoption of a passage in the dissenting judgment of Sir Nicolas Browne-Wilkinson V-C in the Court of Appeal ( QB 730, 779):
19. In Fairchild, Lord Bingham approved this passage as the reason why Wilsher did not fall within the exception. He said, at p 57, para 22:
20. Similarly Lord Hutton, at p 95, para 115, said that "where there is only one causative agent" the McGhee principle could apply and went on to approve the passage from the judgment of Sir Nicolas Browne-Wilkinson V-C in Wilsher.
21. Lord Rodger likewise said, at p 110, para 149, that "the reasoning of the Vice-Chancellor, which the House [in Wilsher] adopted, provided a sound and satisfactory basis for distinguishing McGhee and for allowing the appeal":
22. It was only in my own opinion in Fairchild that the reasoning of Sir Nicolas Browne-Wilkinson was not accepted. I said, at p 77, para 72:
23. This was a minority opinion and, furthermore, I think it was wrong. The question which I raised about different kinds of dust is not so much about the principle that the causative agent should be the same but about what counts as being the same agent. Lord Rodger identified this point when he said, at pp 118-119, para 170:
24. If the distinction between Fairchild and Wilsher does not lie in the fact that in the latter case a number of very different causative agents were in play, I think it would be hard to tell from my Fairchild opinion what I thought the distinction was. In my opinion it is an essential condition for the operation of the exception that the impossibility of proving that the defendant caused the damage arises out of the existence of another potential causative agent which operated in the same way. It may have been different in some causally irrelevant respect, as in Lord Rodger's example of the different kinds of dust, but the mechanism by which it caused the damage, whatever it was, must have been the same. So, for example, I do not think that the exception applies when the claimant suffers lung cancer which may have been caused by exposure to asbestos or some other carcinogenic matter but may also have been caused by smoking and it cannot be proved which is more likely to have been the causative agent.
25. The second issue arising in all three appeals is whether under the Fairchild exception a defendant is liable, jointly and severally with any other defendants, for all the damage consequent upon the contraction of mesothelioma by the claimant or whether he is liable only for an aliquot share, apportioned according to the share of the risk created by his breach of duty.
26. Moses J dealt with the point quite shortly. He said that mesothelioma was an "indivisible injury". It was not like asbestosis, which can be partly caused by one period of exposure and made worse by another. Such an injury is divisible, each defendant being responsible for his contribution to the disease. But the likelihood is that mesothelioma is caused by a single exposure. The more you are exposed, the more likely you are to get it, in the same way as the more you spin the roulette wheel, the more likely is a given number to come up.
27. Counsel for the defendant accepted that mesothelioma was an indivisible injury but argued that since liability was being imposed upon a novel basis, the court should adopt a novel solution for the distribution of liability. Moses J said that on authority it was not open to him to do so. This, he said, was:
28. The judge referred to the well-known statement by Devlin LJ in Dingle v Associated Newspapers Ltd  2 QB 162, 188-189 of the rule which requires that in such a case there should be joint and several liability:
29. In fact, of course, barker was not a case of "concurrent joint tortfeasors, where the actions of either would be sufficient by themselves to produce the consequence." If it had been, there would have been no need to apply the Fairchild exception. The evidence did not establish that the actions of either tortfeasor would by itself have been sufficient to cause mesothelioma. They might have had nothing to do with the onset of the disease. The defendants were held liable because they had each created a material risk that the claimant would contract mesothelioma. But Moses J proceeded on the assumption that, for the purposes of deciding what they should be liable for, each should be deemed to have caused the disease.
30. Likewise in the Court of Appeal, Kay LJ said, at para 44, that if "normal principles" were applied, there could be no apportionment "on the basis that this was an indivisible injury". There had to be some "compelling reason" for departing from the normal rule. He could not find any. There might be some hardship to defendants, particularly as time went on and the number of employers remaining solvent and traceable diminished. But joint and several liability was for the protection of the plaintiff, which was also the purpose of the Fairchild rule itself. Keene LJ said, at paras 51-52, that he had been attracted by the argument for apportionment but concluded that there was no need to depart from the "long established principle applicable in the case of an indivisible injury." Apportionment could lead to the claimant losing part of his damages if one of the defendants became insolvent.
What is the defendant liable for?
31. My Lords, the reasoning of Moses J and the Court of Appeal would be unanswerable if the House of Lords in Fairchild had proceeded upon the fiction that a defendant who had created a material risk of mesothelioma was deemed to have caused or materially contributed to the contraction of the disease. The disease is undoubtedly an indivisible injury and the reasoning of Devlin LJ in Dingle's case would have been applicable. But only Lord Hutton and Lord Rodger adopted this approach. The other members of the House made it clear that the creation of a material risk of mesothelioma was sufficient for liability. Lord Bingham said, at p 68, para 35:
32. Lord Nicholls of Birkenhead likewise said, at p 71, para 45:
33. And in my own opinion, at p 75, para 65, I said much the same:
34. Lord Hutton, as I have already noted, said that in Fairchild the court was required to infer that exposure by the defendant had materially contributed to the disease and Lord Rodger expressed the exception, at p 118, para 168, in the following terms:
35. Consistency of approach would suggest that if the basis of liability is the wrongful creation of a risk or chance of causing the disease, the damage which the defendant should be regarded as having caused is the creation of such a risk or chance. If that is the right way to characterize the damage, then it does not matter that the disease as such would be indivisible damage. Chances are infinitely divisible and different people can be separately responsible to a greater or lesser degree for the chances of an event happening, in the way that a person who buys a whole book of tickets in a raffle has a separate and larger chance of winning the prize than a person who has bought a single ticket.
36. Treating the creation of the risk as the damage caused by the defendant would involve having to quantify the likelihood that the damage (which is known to have materialized) was caused by that particular defendant. It will then be possible to determine the share of the damage which should be attributable to him. The quantification of chances is by no means unusual in the courts. For example, in quantifying the damage caused by an indivisible injury, such as a fractured limb, it may be necessary to quantify the chances of future complications. Sometimes the law treats the loss of a chance of a favourable outcome as compensatable damage in itself. The likelihood that the favourable outcome would have happened must then be quantified: see, for example, Chaplin v Hicks  2 KB 786 and Kitchen v Royal Air Force Association  1 WLR 563.
37. These are of course cases in which there is uncertainty as to what will be, or would have been, the outcome of a known event; for example, the consequences of a fractured ankle, a beauty contest or a lawsuit. The present case involves uncertainty as to the cause of a known outcome, namely, the mesothelioma. But in principle I can see no reason why the courts cannot quantify the chances of X having been the cause of Y just as well as the chance of Y being the outcome of X.
38. Gregg v Scott  2 AC 176 was a case of uncertainty about the cause of a known event. Although this point was to some extent obscured by the fact that Mr Gregg was making a claim for loss of expectation of life and was still alive at the time when he brought his action, there was no finding of uncertainty about what the outcome would be. The judge found as a fact that his expectation of life was substantially less than it would have been if he had not contracted cancer. His loss of expectation of life was therefore damage which he was taken to have suffered at the time when he made his claim, exactly as if he had suffered a broken leg. If he had subsequently died prematurely, that would only have confirmed that the judge's finding about his expectations was correct. The uncertainty in the case was over what had been the cause of the reduced expectation of life. Was it the genetics and life style which caused him to contract cancer, or was it the negligent delay in his diagnosis and treatment? The judge found that the delay had increased the chances of a premature death but not enough to enable him to say on a balance of probability that it would not otherwise have happened. The question before the House was whether Mr Gregg could claim that the damage he suffered was the additional chance of a premature death which had been caused by the delay.
39. Although the House, by a majority, answered this question in the negative, it was not on the ground that there was some conceptual objection to treating the diminution in the chances of a favourable outcome or (putting the same thing in a different way) the increase in the risk of an unfavourable outcome as actionable damage. The reason was that the adoption of such a rule in Gregg v Scott would in effect have extended the Fairchild exception to all cases of medical negligence, if not beyond, and would have been inconsistent with Wilsher, in which the negligent doctor had increased the chances of the baby suffering RLF (or reduced his chances of escaping it). It is plain, at least in my own opinion in the case, at p 197, para 85, that I regarded Fairchild as an example of the very rule which the minority wished to apply. But clearly, if that rule had been applied, Mr Gregg would not have recovered the same damages as if he had proved that Dr Scott had caused his loss of expectation of life. He would have recovered a proportion, related to the extent to which Dr Scott had increased the likelihood that he would suffer a premature death.
40. So far I have been concerned to demonstrate that characterising the damage as the risk of contracting mesothelioma would be in accordance with the basis upon which liability is imposed and would not be inconsistent with the concept of damage in the law of torts. In the end, however, the important question is whether such a characterisation would be fair. The Fairchild exception was created because the alternative of leaving the claimant with no remedy was thought to be unfair. But does fairness require that he should recover in full from any defendant liable under the exception?
41. Lord Bingham in Fairchild, at p 67, para 33, dealt with the competing policy considerations:
42. Lord Rodger, at p 112, para 155, also thought that the balance of fairness came down in favour of liability: