Alasdair Kerr and others against Midlothian Council and another (Court of Session)

Factual and Procedural Background

In 2020, Mrs Kerr experienced symptoms of epithelioid malignant peritoneal mesothelioma, which caused her death in June 2022. She was employed as a chemistry and science teacher during two periods by Company A at two different schools in The City, and also by Company B at another school. During her employment, she regularly handled Bunsen burner heat mats and wire gauzes, some of which contained asbestos. The claimants, Mrs Kerr's husband and family, brought an action for damages alleging that the employers breached their duty by exposing Mrs Kerr to asbestos dust, creating a material increase in the risk of her developing mesothelioma. The case proceeded on liability only, with damages agreed by the parties.

Legal Issues Presented

1. Whether the employers breached their statutory and common law duties by exposing Mrs Kerr to asbestos dust during her employment.
2. Whether Mrs Kerr's occupational exposure to asbestos created a material increase in the risk of developing peritoneal mesothelioma under the special causation rule established in Sienkiewicz v Greif (UK) Ltd.
3. Whether the Fairchild exception to the usual causation requirements applies in this case involving peritoneal mesothelioma and low-level chrysotile asbestos exposure.
4. Whether the claimants proved that asbestos exposure caused or materially contributed to Mrs Kerr's disease.

Arguments of the Parties

Claimants' Arguments

• Mrs Kerr was exposed to asbestos-containing mats and gauzes during her teaching career, including chrysotile and possibly amosite and tremolite fibres.
• It is sufficient to establish a material increase in risk of disease rather than direct causation, relying on the special causation rule in Sienkiewicz and Fairchild.
• The employers should have been aware of the risk and taken precautions under the Control of Asbestos at Work Regulations 1987 and 2002.
• The exposure was consistent with the known latency period for mesothelioma and was orders of magnitude higher than background asbestos levels.
• Medical and expert evidence supports that any asbestos exposure may be associated with mesothelioma development.

Defendant (Company A) Arguments

• The exposure levels were very low, likely limited to chrysotile asbestos, which epidemiological evidence shows does not cause peritoneal mesothelioma at low doses.
• The claimants failed to prove negligence, the extent of exposure, or causation of Mrs Kerr's illness.
• The special causation rule in Fairchild does not apply because it is not established that asbestos caused the disease.
• Guidance and statutory duties regarding asbestos were followed, including replacement of damaged mats.
• Any occupational exposure was negligible and did not materially increase risk.

Defendant (Company B) Arguments

• There is uncertainty about the nature and extent of Mrs Kerr’s employment and exposure during the relevant periods.
• Any asbestos exposure was minimal, likely chrysotile asbestos cement mats, which have low fibre release risk.
• Expert evidence from medical and occupational hygiene specialists supports that the exposure did not cause or materially contribute to the disease.
• The epidemiological evidence does not support a causal link between low-level chrysotile exposure and peritoneal mesothelioma.
• The claimants’ expert evidence was less persuasive and sometimes speculative.

Table of Precedents Cited

Court's Reasoning and Analysis

The court carefully examined the factual evidence regarding Mrs Kerr's exposure to asbestos, concluding it was likely she handled asbestos-containing mats and gauzes, predominantly asbestos cement with possible minor presence of more hazardous amphibole fibres. The court accepted expert evidence estimating a very low cumulative asbestos dose, likely at the lower end of the range presented by the claimants’ expert. The court found the exposure was primarily to chrysotile asbestos, which epidemiological studies show to have a very weak or no causal association with peritoneal mesothelioma at low doses.

The court analyzed medical and epidemiological evidence, including the influential Hodgson and Darnton study, which indicates that peritoneal mesothelioma is extremely rare among those exposed only to chrysotile asbestos and that the risk at low exposure levels is negligible. Expert oncological evidence suggested that Mrs Kerr’s tumour was more likely idiopathic or spontaneous rather than asbestos-related.

Regarding the application of the Fairchild exception, the court held it was not designed for cases where it was not established or admitted that asbestos exposure caused the disease. The exception applies only when asbestos exposure is the sole known cause of mesothelioma and it is impossible to prove which exposure caused it. Since here the evidence did not establish causation or even a material increase in risk, the exception did not apply.

The court emphasized the importance of epidemiological evidence in assessing causation and risk, rejecting the claimants’ submission that any asbestos exposure should be presumed material. The risk of mesothelioma from the low-level chrysotile exposure in this case was found to be de minimis and not material for liability. The court also noted that extending the law to impose liability without proof of causation would conflict with established principles as expressed in Wilsher and other authorities.

In sum, the court found that the claimants failed to prove negligence, material increase in risk, or causation by the employers’ conduct, and that the special causation rule did not apply.

Holding and Implications

The court’s final decision is to DISPOSE OF the claim by pronouncing decree absolving the employers from any liability in damages for Mrs Kerr’s death.

The direct effect is that the claimants receive no compensation as the evidence does not establish that the employers’ conduct caused or materially increased the risk of Mrs Kerr’s peritoneal mesothelioma. The court did not set new precedent but reaffirmed the limitations of the Fairchild exception, particularly its inapplicability where causation by asbestos exposure is not established or admitted. This preserves the established legal framework requiring proof of causation or a material increase in risk for liability in asbestos-related disease claims.