I forgot Novartis Grimsby Ltd v Cookson, [2007] EWCA Civ 1261 at para. 66 for whatever we should take from that passage.
[66] Mr Feeny submitted that, by holding that the present case was analogous to Bonnington, the Recorder had applied the wrong legal test. Although Bonnington had not been overruled or disapproved, it was not nowadays appropriate to adopt the test of causation applied there. Bonnington had only ever applied where the disease was caused gradually by the cumulative effect of the exposure; in other words, where the disease was directly caused by and became gradually worse as the result of year on year exposure to dust (or fumes or noise or vibration or whatever). In such a case, it could properly be said that the negligent component of the exposure had made a contribution to the disease. He submitted that a case which would formerly have been determined in accordance with the principle in Bonninigton would nowadays be subject to apportionment of damages. Where
only part of the exposure had been caused by the defendant's breach of duty, the court would apportion the damages, so as more accurately to reflect the extent of the damage caused by that breach of duty. The claimant would no longer recover all the damages. That had first been done in Thompson and others v Smiths Shiprepairers (North Shields) Ltd [1984] 1 AER 881 (a noise deafness case) and had been followed in many other cases since then.
DC