therefore all emitters are technically contributors to the causal chain. It is the other elements of the tort of negligence (duty of care and breach) together with the requirement that the causal contribution is greater than de minimis that limit the scope of claims for liability. The mesothelioma cases are significant more generally, however, in demonstrating the willingness of the courts to adapt the test of causation where it is in the interests of justice to do so, and where uncertainties in the science obscure identification of the precise causal chain. They also provide guidance on possible approaches to apportionment of damages. In Fairchild v Glenhaven Funeral Services [2002] the UK House of Lords, addressed the issue of causation in the context of asbestos mesothelioma. The court expressed the problem raised by the case as follows: If
(1) C was employed at different times and for differing periods by both A and B, and

(2) A and B were both subject to a duty to take reasonable care or to take all practicable measures to prevent C inhaling asbestos dust because of the known risk that asbestos dust (if inhaled) might cause a mesothelioma, and

(3) both A and B were in breach of that duty in relation to C during the periods of C's employment by each of them with the result that during both periods C inhaled excessive quantities of asbestos dust, and

(4) C is found to be suffering from a mesothelioma, and

(5) any cause of C's mesothelioma other than the inhalation of asbestos dust at work can be effectively discounted, but

(6) C cannot (because of the current limits of human science) prove, on the balance of probabilities, that his mesothelioma was the result of his inhaling asbestos dust during his employment by A or during his employment by B or during his employment by A and B taken together,

is C entitled to recover damages against either A or B or against both A and B? Lord Bingham concluded that he was, stating: I do not therefore consider that the House is acting contrary to principle in reviewing the applicability of the conventional test of causation to cases such as the present. Indeed, it would seem to me contrary to principle to insist on application of a rule which appeared, if it did, to yield unfair results. He emphasised the broad convergence of international jurisprudence on the issue: Whether by treating an increase in risk as equivalent to a material contribution, or by putting a burden on the defendant, or by enlarging the ordinary approach to acting in concert, or on more general grounds influenced by policy considerations, most jurisdictions would, it seems, afford a remedy to the plaintiff. Development of the law in this country cannot of course depend on a head-count of decisions and codes adopted in other countries around the world, often against a background of different 40