Willmore v Knowsley Metropolitan Borough Council (Rev 1)

In a mesothelioma claim, liability may be established where exposure attributable to the defendant materially contributes to the risk that materialises. The exposure must be more than minimal, trivial or inconsequential and must materially enhance the unavoidable background risk. Materiality is an evaluative question. It is not measured or measurable by a fixed dose or duration, and no specific measurement of exposure is required. In an asbestos case, all exposure carries some risk of harm. A finding based on probability and inference is sufficient if supported by evidence. The court may disregard one unsupported exposure source, provided another source independently establishes exposure above the minimal level.

Dianne Willmore developed mesothelioma after attending a comprehensive school between 1972 and 1979. The High Court, at [2009] EWHC 1831 (QB), held the local education authority liable for materially contributing to her asbestos exposure through disturbed or damaged ceiling tiles. Damages were agreed at £240,000 before statutory deductions if liability was established.

The Council appealed, arguing that the judge had confused exposure to asbestos fibres with risk of harm, had failed to find more than minimal exposure, and had relied on unsupported factual findings. The central issue was whether the evidence justified findings of exposure materially increasing the risk of mesothelioma.

Appeal dismissed. The Court of Appeal unanimously upheld the finding of liability.

1. The trial judge had asked the correct legal question. Although some wording referred to exposure to the risk of asbestos fibres, his conclusion expressly addressed whether the identified matters materially increased the claimant’s risk of contracting mesothelioma. There was no confusion between exposure to asbestos and risk of harm.
2. In mesothelioma cases, exposure attributable to a defendant is sufficient if it materially contributes to the risk which later materialises. Culpable exposure must exceed the de minimis level and materially enhance the unavoidable background risk. Materiality is not measured or measurable by a fixed quantity. No specific measurement of exposure duration is required: [2007] EWCA Civ 1189, §21, was applied.
3. The evidence supported the findings concerning asbestos ceiling tiles removed and stacked in the corridor and damaged or stored in the girls’ toilets. Direct evidence of dust release was unnecessary where significant exposure could properly be inferred from the surrounding evidence. The finding concerning bullying in rooms with concrete ceilings was unsupported and could not stand.
4. That partial rejection did not undermine the judgment. In asbestos cases all exposure constitutes a risk of harm, and there is no safe dose. Once exposure above a minimal level is established, one remaining source may sustain liability. Separate exposures may also be considered collectively.
5. The Council’s failure to take reasonably practicable precautions, including isolating work, storing tiles safely and replacing damaged asbestos materials, amounted to breach of duty on the trial judge’s findings. The conclusion that avoidable school exposure materially contributed to the eventual illness was reasonably open on the evidence and disclosed no error of law. The principle from Fairchild v Glenhaven Funeral Services Ltd [2003] 1 AC 32 was applied.

• Court of Appeal (Civil Division) dismissed the Council’s appeal and upheld the finding of liability.
• High Court, Queen’s Bench Division, Liverpool District Registry, Nicol J, held the Council liable for materially contributing to the claimant’s asbestos exposure: [2009] EWHC 1831 (QB).