Wandsworth Borough Council, R (on the application of) v HM Senior Coroner For Inner West London

In a coronial investigation, causation must be established on the balance of probabilities. It is insufficient that a disease is statistically associated with a suspected cause, or that the suspected exposure is merely possible. There must be evidence specific to the deceased showing that the relevant event or conduct made an actual and material contribution to the death. A coroner need not investigate every theoretically possible alternative explanation, but must not place greater weight on limited evidence than it can properly bear. The civil asbestos principle that liability may follow from materially increasing the risk of mesothelioma does not apply to coronial investigations.

The claimant local authority sought judicial review of the senior coroner’s findings and narrative conclusion concerning the death of Linda Johns. The coroner had concluded that Mrs Johns died from malignant mesothelioma caused by asbestos exposure while she lived in the council’s property. The council argued that the evidence established, at most, a possibility of exposure at that address and did not show that it caused or materially contributed to the death.

The central issue was whether the coroner was entitled to conclude, on the balance of probabilities, both that asbestos exposure caused the mesothelioma and that the relevant exposure occurred at the council property.

1. Outcome. The court quashed the findings in Box 3 and the conclusion in Box 4 of the Record of Inquest. It substituted a finding that Mrs Johns was diagnosed with malignant mesothelioma in July 2018 and that, despite treatment, this led to and caused her death on 27 August 2018. The narrative conclusion was substituted with malignant mesothelioma.
2. Standard and causation. The coroner was required to make findings on the balance of probabilities. For causation, the relevant event or conduct had to make more than a minimally, negligibly or trivially small contribution to death. In coronial proceedings this required an actual and material contribution.
3. Insufficient evidence of asbestos causation. The strong statistical association between asbestos exposure and mesothelioma could not, without case-specific evidence, establish causation in an individual case. The presence of asbestos-containing materials in the flat did not itself prove exposure to freely circulating asbestos fibres. The October 2003 removal work created a possible route of exposure, but there was no evidence that the dust released by the malfunctioning equipment contained asbestos fibres.
4. Insufficient evidence of source. The latency period, the consistency of the illness with asbestos exposure and the absence of an industrial employment history established no more than a possibility that exposure at the flat caused the disease. Even if exposure occurred there, the evidence did not establish on the balance of probabilities that it was the source which made an actual and material contribution during a lengthy latency interval in which other exposure was possible.
5. Limits of expert evidence and inquiry. The pathologist’s view that it was reasonable to assume exposure at the flat had caused the mesothelioma went beyond his medical expertise. The issue was for the coroner on the totality of the evidence. The coroner was not required to conduct an exhaustive inquiry into every theoretical alternative explanation; the error was instead the excessive weight placed on insufficient evidence.
6. Civil asbestos principles. The material-increase-in-risk principle applicable in civil asbestos litigation had no application in the coronial investigation, where actual and material contribution had to be established.

First-instance judicial review proceedings. No earlier decision in the same litigation was stated in the judgment.