Wood v Ministry of Defence [07.07.11]

The Court of Appeal upholds decision that exposure at work caused a neurological condition. The Claimant claimed damages for a neurological condition akin to Parkinson’s disease which he alleged had been caused by his exposure to organic solvents during the course of his service as a painter and finisher in the RAF. During the hearing the Defendant made an admission of breach of duty for the period between 1987 and 1995, relying on Crown immunity from suit for the period before then. However, it disputed that the breach had caused the Claimant any damage.

The MoD contended that:

  • The Claimant had not suffered any permanent neurological damage and his symptoms were entirely or almost entirely due to psychological factors.
  • Although solvents could cause temporary effects to the nervous system, there was no satisfactory scientific evidence that they could cause permanent damage short of death.  

At first instance His Honour Judge Taylor found in favour of the Claimant.


Lady Justice Smith upheld the first instance decision:

  • Although the evidence pointed fairly clearly to the presence of some functional overlay, on the evidence HHJ Taylor had been entitled to find that the Claimant’s condition was organic.
  • There were some errors in the first instance judgment, but they did not give rise to any real suspicion that the Judge had not understood and accepted the main arguments on causation. There was clear evidence of a very high level of exposure. There was also "some" scientific evidence of an association between heavy solvent exposure and neurological damage. This was sufficient to satisfy a judge on causation on the balance of probabilities, even if it was not yet established "in the scientific sense" that there is a causal connection between heavy solvent exposure and chronic neurological damage.  


This case is an interesting example of the distinction between the scientific standard of proof and the standard applied in civil litigation.

The Claimant called evidence in support of a causal connection from a Professor of Environmental and Occupational Medicine, Professor Anthony Seaton. The Defendant characterised Professor Seaton as an "evangelist" in relation to the link between solvent exposure and chronic neurological disease, and argued that his opinion was not soundly based in scientific work.

Professor Seaton acknowledged that the evidence he relied upon did not prove the link in scientific terms, but had been sufficient to persuade him that the link existed. On the basis of his evidence, and in the absence of contrary expert evidence, the Court concluded that a causal link had been established on the balance of probabilities, which was the legal, if not scientific, standard of proof. As stated by Smith LJ, "Whereas an epidemiologist will not declare that there is an association unless the study shows that it is 95% certain that the apparent association cannot be the result of chance, the judge in a civil claim need only be satisfied that it is more likely than not that the condition in question has been caused by the alleged exposure."

Merely arguing that causation is not established in the scientific sense will not be sufficient. It will still be open to the court to conclude that the association is more likely than not, and find for the claimant. What is required is persuasive evidence from a suitably qualified expert to undermine the analysis of the claimant’s expert.