In another Court of Appeal decision, the defendant had appealed against a decision that it was liable to compensate the claimant, who had been employed in its dye plant, for his development of carcinoma of the bladder.

The judge found that his condition was caused by severe exposure to carcinogens in the form of aromatic amines used in the production of dyestuffs. There was evidence that dust from the finished dyestuffs contained amines. The claimant had been a moderate smoker for about 20 years. It was agreed that cigarettes also caused bladder cancer.

The experts disagreed on whether it was the exposure or the smoking that had caused the condition. The Judge preferred the evidence of the claimant’s expert who found that, of the two contributory causes, the occupational exposure had been the major contributing cause.

The defendants appealed on the basis that the Judge had failed to analyse the implications of his findings of fact in order to reach a proper conclusion on the issue of breach of duty; that he had equated the fact of exposure with causation of the cancer; and he had applied the wrong legal test for causation and had permitted the claimant to prove causation by showing only that the occupational exposure had made a material contribution to the risk.

The Court of Appeal rejected the appeal. They said that the defendants had made significant admissions in relation to breach of duty and had conceded that the claimant had been exposed to the dust and that its protective measures were inadequate. Given that there was clear evidence that the defendants had been aware of the dangers of amines for several decades, the failure to minimise the exposure was itself a breach of duty.

On the argument between the relative potency of smoking and occupation exposure, published opinion did not provide any answer as to whether the risk arising from occupational exposure would decrease through the passage of time. The Judge was entitled to prefer the claimant’s evidence and had given reasons for doing so.

The Judge accepted the evidence that occupational exposure was the major contributing course, clarified by the claimant as contributing 70 per cent of the total risk. If the correct tests for causation was the “but for” test, that test was plainly satisfied on the facts as found.

Novartis Grimsby Limited -v- Cookson, 29 November 2007, Court of Appeal.