Game of chance

Yet again, an asbestos case has landed in the Supreme Court which is hoped to end the seemingly ever-evolving arguments, but which is more likely to give rise to fresh debate.

We can take some comfort from Lady Hale's opening remark in the Sienkiewicz v Greif [2011] UKSC 10 judgment: 'I pity the practitioners as well as the academics who have to make sense of our judgments in difficult cases.'

In Fairchild v Glenhaven [2002] UKHL 22, the House of Lords established that, for multiple asbestos exposure cases, damages for the indivisible disease of mesothelioma fell to be paid jointly and severally by any defendant proven to have made a material contribution to tortious exposure.

The tables were turned in Barker v Corus UK Ltd [2006] UKHL 20, with defendants held only liable for their relative contribution to risk (apportionment) but reversed again by section 3 of the Compensation Act 2006 to the welcome relief of asbestos claimants. The Supreme Court's judgment in Sienkiewicz, handed down on 9 March, marks the latest chapter in a well-explored armoury of mesothelioma appeals since Fairchild, but this time concentrated on low-level exposure cases from a 'single exposure' source.

Mrs Enid Costello (represented by her daughter, Karen Sienkiewicz) worked at a factory in Ellesmere Port between 1966 and 1984. As an office worker she had no direct contact with asbestos, but suffered low-level exposure to asbestos during the course of her work which regularly took her around the factory floor. Along with other Ellesmere Port residents, she was also exposed to asbestos in the general environment.

Between 1972 and 1979, Diane Willmore was a pupil at Bowring Comprehensive where she was exposed to asbestos from ceiling tiles used in the building which were temporarily stacked in corridors, stored in the girls' toilets and occasionally damaged by other pupils misbehaving when they hid property in the ceiling cavities.

Both women went on to develop mesothelioma and, as is all too inevitable in mesothelioma appeals, died before the cases concluded (Enid Costello in 2006 and Diane Willmore in 2009).

The question taken before the courts in both cases was whether or not the exposure was sufficient to have made a 'material contribution' to the risk of mesothelioma.

Epidemiological evidence advanced in Mrs Costello's case assessed the environmental risk in Ellesmere Port at 24 cases per million. The exposure in the defendant's factory took that figure up to 28.39 cases per million, an increase of 18 per cent. HHJ Main QC found that since the exposure in the factory had not 'doubled the risk' (to, for example, more than 48 cases per million) it could not be said that the occupational exposure had made a material contribution to risk.

In Mrs Willmore's case, Mr Justice Nicol found, based on the witness evidence, that the exposure was above de minimis and therefore made a material contribution to the risk of mesothelioma. That, combined with a finding of breach of duty, was sufficient to establish Mrs Willmore's case.

On appeal, Mrs Costello's daughter (Sienkiewicz) succeeded in persuading Lady Justice Smith that it was not necessary to prove causation by reference to a doubling of risk; the simple question to be asked was whether the tortious exposure had materially increased the risk. This ruling was reflected in Willmore when the Court of Appeal upheld that the school-time exposure was enough to establish a material contribution to risk.

Undeterred the defendants sought to exploit another chink in the Fairchild armour and, in October 2010, both parties ended up in the Supreme Court. The seven justices, however, found unanimously in the claimants' favour, with Lord Phillips giving the leading judgment. Section 3 of the Compensation Act was found to have been simply a reversal of the Barker decision. The court ruled there was nothing in the Act to prevent the defendants advancing their arguments over the 'double the risk' argument.

That gave rise to an analysis of the epidemiological evidence. For the uninitiated, epidemiology is concerned with assessing the statistical probability of an event (i.e. mesothelioma) occurring within a population (i.e. Ellesmere Port). Lord Phillips recognised the difficulties in applying epidemiology to mesothelioma claims due to the lengthy latency periods and the fact that most data relates to asbestos victims rather than the population at large. He found the threshold to be 'a very fine one' and expressed concern that 'epidemiological data may not be reliable'.

He found the lack of scientific knowledge about mesothelioma rendered a decision on causation based on epidemiology as 'inappropriate' and he therefore rejected the doubling of risk test as a 'tenuous basis' for establishing causation. Note, however, the use of the wording 'cause in fact' which it is assumed can be taken to mean causing the disease, as opposed to causing the risk of the disease. The same issue is explored below in relation to lung cancer.

Material contribution?

In the absence of the doubling of risk test, Lord Phillips went on to consider 'What constitutes a material increase in risk?'

However, the closest he gave to an answer appeared to be the somewhat circular reply 'any exposure which is not de minimis'. While the court seemed keen for there to be a lower threshold, it strove to avoid saying where the line is drawn, with Lord Phillips doubting 'whether it is ever possible to define' de minimis exposure.

It may be helpful to take a starting point in terms of multiple exposure and single exposure cases. Multiple exposure, at the heart of Fairchild, concerns (typically) more than one employer exposing the victim to asbestos and the inability of medical science to establish on the balance of probabilities which of the exposures caused mesothelioma. The Compensation Act approved the Fairchild test that exposers be held to be liable where they have made a 'material contribution'.

But what of the situation where one employer is responsible for 99.5 per cent of the dust and the other for 0.5 per cent? Is 0.5 per cent de minimis? Typically, that is the approach taken by medical experts in their reports and this appeared to be approved by Lord Phillips, who concluded: 'The only circumstances in which a court will be able to conclude that wrongful exposure ofa mesothelioma victim to asbestos dust did not materially increase the victim's risk of contracting the disease will be where that exposure was insignificant compared to the exposure from other sources.'

However, note the inclusion of the word 'only' in the paragraph above. Can the same be said for single exposure cases? If Mrs Costello's factory exposure had increased her risk from, for example, 24 cases per million to 24.1 cases per million, would the result have been different? The relevant contributions in those circumstances would have been 99.6 per cent environment versus 0.4 per cent factory. Would it still be consistent to argue 0.4 per cent is a material contribution?

Lord Phillips appeared to allude tothat thinking, quoting the medical wisdom that 'there is no known lower threshold of the exposure that is capable of causing mesothelioma'.

Indeed, given the comments on the limitations of epidemiology, the de minimis argument will be a hard fight for defendants in single exposure cases, particularly when Lord Browne described it as 'a lost cause'.

Lung cancer

The question that may arise now is the application of the judgment to non-mesothelioma cases, specifically asbestos-related lung cancer.

Certainly, the signs are encouraging for claimants. Lord Phillips said that the Bonnington rule should apply 'where the disease is indivisible, such as lung cancer'. In considering Shortell he said that he did not see it as 'essential' to prove 'the doubling of risk'.

He also explored the theory further for 'dose related' illnesses (e.g. asbestosis, pleural thickening) and queried the chronological occurrence to the cause of the disease; for example, if the 'innocent' (say, self-employed) exposure occurred first and was sufficient in itself to give rise to the illness, would subsequent, tortious, exposure be deemed to have contributed to the cause? Although no answer was given, Lord Phillips commented that epidemiology may be of assistance.

Can it therefore be argued that, where a lung cancer victim has suffered asbestos exposure, any material contribution is enough to establish causation? With the uncertainty over the 'synergistic relationship' between smoking and asbestos, epidemiology may yet have a part to play and the likelihood is that the next battleground has been drawn. The answer may lie between distinguishing contribution to disease (Bonnington) and contribution to risk (Barker). The query arises over whether the claimant needs to prove a doubling of risk to establish contribution to risk and, in light of Lord Phillips' comments, arguably the answer is 'no'.

A trickle or a flood

Defendants have decried how Sienkiewicz may give rise to speculative cases. This may turn out to be the case, but, equally, it could be that the increase is more likely to be a trickle than a flood. While mesothelioma cases are still thought to be reaching their peak, the number of victims is limited (between 2,000 and 2,500 per year) and only some of those will make a claim. Of those who do claim, not all concern low-level exposure and many do not even touch upon these issues.

Claimants still also need to get over the hurdle of proving breach of duty, and the court issued warnings over judicial sympathy giving rise to a 'lax approach to the proof of the essential elements'. The comments made concerning the judicial assessment of Mrs Willmore's exposure came across as guarded criticism, describing the judgment as 'very generous' and even 'truly heroic'. Note that Greif sought to argue (albeit unsuccessfully) they had not breached their duty to Mrs Costello. Undoubtedly, defendants will be seeking to focus their efforts on this area to achieve findings more in keeping with Brett v Reading University [2007] EWCA Civ 88.

For now, low-level mesothelioma cases are probably likely to give rise to fewer arguments on causation and a lesser need for engineers input. This should be welcomed by both sides given the time and cost usually involved in obtaining engineering reports. I hope this will enable cases to be resolved more quickly and within claimants' lifetimes, and that it will be the distant future before we see another fresh set of mesothelioma appeals holding up compensation to claimants.