WORKERS' COMPENSATION (DUST DISEASES) BOARD v KELLY

THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40703/99 CC 261/99 SHELLER JA POWELL JA ROLFE AJA

WORKERS' COMPENSATION (DUST DISEASES) BOARD v KELLY In 1988, Mr Scates was diagnosed as suffering from squamous cell carcinoma of the lung. He had been employed between 1957 and 1974 at the Tamworth Power Station where he was regularly exposed to moderate levels of asbestos dust. While such exposure could cause squamous cell carcinoma of the lung, there was no evidence confirming retained asbestos fibres in his lungs. Up until 1994, Mr Scates had been a moderate smoker for 50 years. Following a certificate issued by the Medical Authority under the Workers' Compensation (Dust Diseases) Act 1942 stating that he had not contracted a dust disease within the meaning of the Act, Mr Scates appealed to the Compensation Court naming the Workers' Compensation (Dust Diseases) Board as the respondent. The appeal was upheld by Bishop CCJ. Among his Honour's findings were the findings that asbestos and tobacco were recognised carcinogen, that there was a multiplicative synergistic relationship between the two carcinogens, and that, although medical tests showed no evidence of asbestos bodies and Mr Scates exhibited no signs of any reaction to asbestos inhalation, there was overwhelming evidence that such indications did not preclude the possibility of Mr Scates having been exposed to significant levels of asbestos. All expert witnesses accepted that the evidence established that Mr Scates underwent exposure to asbestos at a level more than enough to cause asbestosis. His Honour concluded that it was more probable than not that as a result of the synergistic effects of exposure to asbestos and tobacco smoke, Mr Scates's employment materially contributed to his lung cancer. The Board appealed from Bishop CCJ's decision. Before this appeal was heard, Mr Scates died and Ms Kelly (an administrator ad litem) was substituted as the respondent. Held: (by Sheller JA, Powell JA and Rolfe AJA agreeing)

1. While the incapability of evidence to prove a fact is a question of law, whether such evidence, though capable of doing so, is, in the circumstances and in the context of other evidence, sufficient to prove the fact is a question of fact and raises no question of law. Azzopardi v Tasman UEB Industries Limited (1985) 4 NSWLR 139, discussed.
2. There was evidence before the trial Judge from various disciplines that Mr Scates's employment at the power station materially increased the risk that he would contract lung cancer and there was medical evidence that exposure to asbestos dust materially contributed to the lung cancer. Therefore there was evidence upon which the trial Judge could find, on the balance of probabilities, that the lung cancer arose out of the employment, in the sense that exposure to asbestos dust in the course of employment caused or materially contributed to the lung cancer. Accordingly, the appeal merely challenged the trial Judge's findings of facts and raised no question of law. Azzopardi v Tasman UEB Industries Limited (1985) 4 NSWLR 139, applied. Seltsam Pty Limited v McGuiness [2000] NSWCA 29, applied. St George Club Limited v Hines (1961) 35 ALJR 106, applied. Sydney County Council v Furner (1991) 7 NSWCCR 210, distinguished.
3. If a wrongful act results in an increased risk of injury to the plaintiff and that risk eventuates, the defendant's conduct has materially contributed to the injury that the plaintiff suffers whether or not other factors also contributed to that injury occurring. The trier of fact is entitled to conclude that the act caused the injury in question unless the defendant establishes that the conduct had no effect at all or that the risk would have eventuated and resulted in the damage in question in any event. Bendix Mintex Pty Limited v Barnes (1997) 42 NSWLR 307, referred to. McGhee v National Coal Board [1973] 1 WLR 1, referred to. Naxakis v Western General Hospital (1999) 73 ALJR 782, referred to. Wilsher v Essex Area Health Authority [1988] 1 AC 1074, referred to. ORDERS Appeal dismissed with costs.

THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 40703/99 CC 261/99 SHELLER JA POWELL JA ROLFE AJA

WORKERS' COMPENSATION (DUST DISEASES) BOARD v KELLY JUDGMENT

On 17 December 1998 the Medical Authority appointed under the Workers' Compensation (Dust Diseases) Act 1942 (the Act) issued a certificate of non-disablement in respect of the respondent, Patrick James Scates, certifying that the Authority was of the view that Mr Scates, the worker, had not contracted a dust disease within the meaning of the Act. Mr Scates appealed to the Compensation Court pursuant to s8I of the Act. The respondent in that appeal was the Workers' Compensation (Dust Diseases) Board (the Board) constituted under the Act. No procedural exception was taken to this. The parties agreed that the issues on the appeal should be dealt with under an amended application for determination filed in the Compensation Court on 10 August 1999, in which Mr Scates claimed that he suffered squamous cell carcinoma of the lung caused by exposure to asbestos dust and fibre in the course of his employment between March 1957 and March 1978 at the Tamworth Power Station. 2 On 20 August 1999 Bishop CCJ upheld the appeal and directed that a new certificate consistent with his reasons for judgment be issued. The Board appeals to this Court from Bishop CCJ's decision. The board concedes that, pursuant to s32 (1) of the Compensation Court Act 1984, its appeal is limited to a point of law. After Bishop CCJ gave his decision, Mr Scates died. An administrator ad litem, Cynthia Pauline Kelly, has been appointed and substituted on the record as the respondent.

UNCONTESTED FACTS 3 The relevant uncontested facts can be summarised in the following way. In 1998 Mr Scates was diagnosed as suffering from squamous cell carcinoma of the lung. During a period from March 1957 until sometime probably in 1974, Mr Scates had been employed at the Tamworth Power Station. While he was at work during this period of employment, he was regularly exposed to moderate levels of asbestos dust. Such exposure can cause lung cancer of the type Mr Scates was diagnosed to have. Radiological investigations in 1998, which did not include a high resolution CT scan, revealed no evidence of asbestos related disorders affecting the lung, parenchyma or pleura. There was no clinical evidence confirming retained asbestos fibres in Mr Scates's lungs. 4 In 1943 Mr Scates joined the Royal Navy. He had no recollection of exposure to asbestos in that service. While in the navy he began smoking, a habit he continued during the next 50 years until about 1994. The level of smoking was of the order of 15 to 20 cigarettes per day and therefore could be described as moderate. His employment after he left the navy in 1947 until he joined the Electricity Commission in 1957 did not involve asbestos products or asbestos insulation.

FINDINGS 5 At the hearing in the Compensation Court, medical specialists in the fields of pathology, radiation oncology, occupational medicine and respiratory medicine were called on behalf of Mr Scates. A chest physician with a particular interest in asbestos and its effects on the human body was called for the Board. Bishop CCJ carefully summarised the evidence and made findings including a finding that both asbestos and tobacco are recognised carcinogens. There is a synergistic relationship between these two carcinogens which is multiplicative. Although the radiological and pathological tests carried out on Mr Scates were neutral and revealed no evidence of asbestos bodies or any clinical signs of any reaction to the inhalation of asbestos, the evidence was overwhelming that such indications did not preclude the possibility of Mr Scates having been exposed to significant levels of asbestos. 6 Bishop CCJ regarded it as significant that Mr Scates's experts had expertise in a variety of disciplines. From the angle of their individual disciplines they all very firmly supported his case. The evidence of Mr Scates's exposure to asbestos was very thorough and detailed, there was no protection available and the latency period was statistically acceptable from the point of view of the identification of the tumour. Part of Mr Scates's duties of chipping away in an enclosed space asbestos that had been baked at a very high temperature involved very high danger. All experts accepted without qualification the Helsinki Criteria under which the evidence in the case established that Mr Scates underwent exposure to asbestos at a level more than enough to cause asbestosis. Mr Scates's witnesses were all firmly of the view that, on the probabilities, he would have a high fibre burden in his lungs. There was clear evidence that his smoking history would have impeded his clearance of asbestos fibres from his lungs. Bishop CCJ said: "It is more probable than not that as a result of the synergistic effects of exposure to asbestos and tobacco smoke [Mr Scates's] employment at the Tamworth Power Station materially contributed to his carcinoma of the lung." EVIDENCE 7 Before coming to the grounds of appeal there are particular matters in the evidence which can helpfully be referred to. On 20 - 22 January 1997 the International Expert Meeting On Asbestos, Asbestosis and Cancer was convened in Helsinki to discuss disorders of the lung and pleura in association with asbestos and to agree upon state of the art criteria for their diagnosis and attribution with respect to asbestos. A document was produced as a result and named the Helsinki Criteria. The document contained diagnostic criteria for conditions which included lung cancer. These criteria were related to periods of exposure relevantly described as one year of heavy exposure to asbestos (eg manufacture of asbestos products, asbestos spraying, insulation work with asbestos materials, demolition of old buildings) or five to ten years of moderate exposure (eg construction, shipbuilding) which might increase the lung cancer risk twofold or more over that of people not so exposed. Under the heading "Lung Cancer" it was said: "Estimates of the relative risk for asbestos-associated lung cancer are based on different-sized population. Because of the high incidence of lung cancer in the general population, it is not possible to prove in precise deterministic terms that asbestos is the causative factor for an individual patient, even when asbestosis is present. However, attribution of causation requires reasonable medical certainty on a probability basis that the agent (asbestos) has caused or contributed materially to the disease. The likelihood that asbestos exposure has made a substantial contribution increases when the exposure increases. Cumulative exposure, on a probability basis, should thus be considered the main criterion for the attribution of a substantial contribution by asbestos to lung cancer risk. For example, relative risk is roughly doubled for cohorts exposed to asbestos fibres at a cumulative exposure of 25 fibre-years or with an equivalent occupational history, at which level asbestosis may or may not be present or detectable. Heavy exposure, in the absence of radiologically diagnosed asbestosis, is sufficient to increase the risk of lung cancer. Cumulative exposures below 25 fibre-years are also associated with an increased risk of lung cancer, but to a less extent. …. A minimum lag-time of 10 years from the first asbestos exposure is required to attribute the lung cancer to asbestos. …. Although tobacco smoking affects the total lung cancer risk, this effect does not detract from the risk of lung cancer attributable to asbestos exposure. No attempt has been made in this report to apportion the relative contributions of asbestos exposure and tobacco smoking." 8 A specialist pathologist, Professor Shilkin, was called on behalf of Mr Scates. Professor Shilkin referred to the occupational history of Mr Scates and the Helsinki Criteria and concluded that moderate exposure to asbestos over a five to ten year period might increase the risk of lung cancer twofold. The trial Judge said: "Once that twofold risk is reached the Criteria suggest that it is more probable than not that the lung cancer is related to asbestos exposure. …. With regard to smoking the doctor indicated there was a multiplicative effect with asbestos and tobacco in smokers. However, [Mr Scates's] smoking history, variable as it was, would probably be sufficient on its own to account for the development of lung cancer….. On the basis of tests and research [Professor Shilkin] indicated that he was quite content in the present situation to simply accept the industrial history as an indicator of contribution without any confirmatory signs of asbestos induced clinical abnormality." 9 Another expert Mr Scates called was Dr Allan Langlands, a radiation oncologist with lengthy experience and qualifications. He concluded that the exposure at the power station very significantly contributed to the development of Mr Scates's carcinoma irrespective of whatever level of tobacco exposure might be accepted by the Court. Dr James Leigh, another witness called by Mr Scates, had specialist qualifications in a number of areas including medicine with particular interest in occupational medicine and asbestos related diseases. Despite the absence of tissue for testing and the absence of any abnormal findings on radiology or pathological testing, Dr Leigh considered that Mr Scates's exposure to asbestos had made, on the balance of probabilities, a material contribution to the cancer. 10 Dr Keay Foster, a specialist consultant in respiratory medicine with extensive experience and post-graduate qualifications and a special interest in asbestos related diseases, considered that the history as taken complied with the Helsinki Criteria and that the cause of Mr Scates's lung cancer was both his smoking and his occupational exposure to asbestos. 11 Such evidence led to and supported Bishop CCJ's finding that the asbestos exposure which Mr Scates endured while working at the Tamworth Power Station materially contributed to his carcinoma. The parties accepted that this was a correct statement of the necessary causative link between exposure and dust disease without any need to construe the language of the Act or the definition of dust diseases in Schedule 1 thereto. 12 This being so, the first matter raised on behalf of the respondent was that no appeal lay under s32 of the Compensation Court Act because the Board's challenge was to a finding of fact. The respondent relied upon the decision of this Court in Azzopardi v Tasman UEB Industries Limited (1985) 4 NSWLR 139 particularly at 155-157 in the judgment of Glass JA. Mr Hoeben SC, who appeared for the Board, sought to draw a distinction in this case by reference to a passage in that judgment at 156 in which Glass JA said: "…..that alleged insufficiency of evidence to prove a fact always raises a question of law". Mr Hoeben submitted that there was such an insufficiency of evidence in this case. He conceded, I think correctly, that the phrase "insufficiency of evidence" used in a judgment with which Samuels JA agreed and which has, since it was given, been taken in this State as authoritative upon the point, must be read to mean that the evidence led, even if accepted, is not capable of proving the fact. Whether the evidence, though capable of doing so, is, in the circumstances and particularly in the context of the other evidence, sufficient to prove the fact is a matter for the fact finder and raises no question of law.

THE APPELLANT'S SUBMISSIONS 13 Mr Hoeben relied on St George Club Limited v Hine (1961) 35 ALJR 106. At 107, the High Court (Dixon CJ, Kitto, Taylor, Menzies and Windeyer JJ) said: "We were requested by counsel for the appellant to decide this case by reference to the following concession which they made: '… if there was evidence upon which his Honour Judge Dignam could find on the probabilities that the myocardial infarction arose out of the employment in the sense that the exertion of the work on 21 May caused or materially contributed to the myocardial infarction then this appeal should fail.' We have reached the conclusion that there was such evidence and the appeal must therefore fail. ….. In an action at law a plaintiff does not prove his case merely by showing that it was possible that his injury was caused by the defendant's default, Bonnington Castings Limited v Wardlaw ([1956] AC 613); nor does proof of default followed by injury show that the default caused the injury for as Viscount Simonds said in Quinn v Cameron and Roberton Limited ([1958] AC 9 at 23), 'Post hoc, ergo propter hoc' is a fallacy in respect of a breach of a statutory regulation as it is in respect of any other event in life'." 14 In Seltsam Pty Limited v McGuiness [2000] NSWCA 29, decided after oral argument in this appeal was complete, Spigelman CJ said at para 119: "There is a tension between the suggestion that any increased risk is sufficient to constitute a 'material contribution', and the clear line of authority that a mere possibility is not sufficient to establish causation for legal purposes. The latter is too well established to be qualified by the former." 15 At para 34 and following, the Chief Justice referred to the expert evidence, that of an epidemiologist, Dr McCredie, based on statistics, and that of a medical practitioner, based on various possibilities of causative connection and epidemiology. In the present proceedings, the trial Judge noted the significance of a wider variety of disciplines among the experts. The Chief Justice said at para 89: "In my opinion, evidence of possibility, including epidemiological studies, should be regarded as circumstantial evidence which may, alone or in combination with other evidence, establish causation in a specific case."

His Honour concluded at para 183: "Epidemiological studies and expert epidemiological opinion evidence on general causation go no further than establishing a possibility. Applying a common sense test of causation to the evidence of possibility in the present case does not, in my opinion, justify an inference of causation on the balance of probabilities in the individual case." 16 The question in Seltsam Pty Limited v McGuiness was whether there was a causal connection between exposure to asbestos and renal cell cancer. At para 284, Davies AJA remarked that most studies, and there have been many of them, have found no association between asbestos and renal cell cancer. In conclusion, Davies AJA said that in his opinion "the current state of the epidemiological evidence, as disclosed by the evidence of this case, is that a causal relationship between asbestos and renal cell cancer has not been established." He agreed with the Chief Justice that the appeal should be upheld. Stein JA dissented. He referred to The Commonwealth v McLean (1996) 41 NSWLR 389 at 410 and the remarks therein of Handley and Beazley JJA that a tribunal of fact (causation being a question of fact) is entitled to find causation as a matter of common sense "from the sequence of events, although medical science does not support an affirmative answer, provided it does not exclude such a finding." His Honour examined the evidence in some detail and said in his opinion that there were "a host of reasons why the trial Judge was entitled to prefer Dr McCredie and find that, on the balance of probabilities, the link between asbestos and RCC was established." 17 Mr Hoeben submitted that in these proceedings there was only evidence of a statistical probability that a person, exposed to asbestos dust at the level and for the period during which Mr Scates was exposed, would contract lung cancer and evidence that he developed lung cancer. There was no connecting link between the risk or increased risk from the exposure to the dust and the lung cancer. In particular, there was no radiological or other evidence of the presence of dust damage in the tissue. The significance of this was heightened by the statistical probability that Mr Scates's smoking caused the cancer. 18 Mr Hoeben referred to the decision of this Court in Sydney County Council v Furner (1991) 7 NSWCCR 210. That was a claim by a worker who suffered from lung cancer and who had been exposed to creosote in the course of his employment. Creosote can cause cancer in humans. The worker was a heavy smoker. A doctor, whose speciality was cancer research, with particular regard to chemical carcinogenesis, was called on behalf of the worker. The witness said that he believed that the major cause of the worker's lung cancer was his smoking but that exposure to creosote could not be excluded as a causative factor of that cancer because it was, like cigarette smoking, a known carcinogen which played either a primary causative role or secondary causative role by synergism or interaction between the two risk factors. 19 The trial Judge had said: "When one removes from one's consideration a necessity to isolate the strongest cause, that is the one from which the effect is most likely to have resulted from, then one can say that all causes are capable of producing the event"; see 213E. Hope AJA, who gave the judgment with which the other members of the Court agreed, said at 213F: "With respect to his Honour, as it seems to me, this last sentence leaves any particular cause in the area of possibility and not of probability. If all that one can say is that all causes, including the relevant cause, are capable of producing the event, one says no more than that it is possible that the particular cause did produce the event; one does not say that the particular cause probably did produce the event."

As will have been seen, the evidence which Bishop CCJ accepted from the medical experts was not of this kind. 20 Mr Hoeben placed considerable reliance upon the judgment of Mason P in Bendix Mintex Pty Limited v Barnes (1997) 42 NSWLR 307 and particularly, I think, the passage at 318 where Mason P, after reviewing the cases and the ways in which the common law has sought to address the difficulty of plaintiffs faced with multiple defendants yet uncertain as to which of them was legally responsible, said: "But none of these procedural or adjectival concessions in favour of the uncertain plaintiff support the principle that a party who negligently exposes a plaintiff to a risk of injury will be liable unless the plaintiff can persuade the trier of fact that it was probable that the risk came home. The basal principle remains that: 'The law never gives judgment in favour of a plaintiff when the only finding is equally consistent with liability and non-liability.' ( Moriarty v Evans Medical Supplies [1958] 1 WLR 66 at 91, per Lord Denning.)" 21 In Bendix the respondent had, during his service with the Royal Navy from 1947 to 1962, been exposed to asbestos. The appellants were a subsequent employer of the respondent at a service station, where, during that employment and later when self-employed, he was exposed to asbestos dust from working on brake and clutch componentry, and the manufacturers and suppliers of that componentry. At 319 Mason P said that the appeals must succeed. "The evidence does not establish the probability that it was any of the appellants (as distinct from the Royal Navy) whose negligence was the cause of Mr Barnes' injuries. Indeed the evidence points firmly in the opposite direction." 22 I do not understand anything said by the President to detract from the validity of what Lord Bridge of Harwich in Wilsher v Essex Area Health Authority [1988] 1 AC 1074 at 1090 described as the robust and pragmatic approach adopted by the majority in McGhee v National Coal Board [1973] 1 WLR 1 to the facts of that case, notably that brick dust adhering to the skin was a recognised cause of industrial dermatitis of the sort from which the pursuer suffered; see Wilsher at 1086. The error isolated by Lord Bridge at 1080 was the trial judge's statement of the principle of law in the following terms: "It seems to me that it follows from McGhee that where there is a situation in which a general duty of care arises and there is a failure to take a precaution, and that very damage occurs against which the precaution is designed to be a protection, then the burden lies on the defendant to show that he was not in breach of duty as well as to show that the damage did not result from his breach of duty." 23 If, in a given case, mesothelioma from which a worker is found to be suffering is shown to have been caused by exposure to asbestos dust and one of the worker's employers had, during an appropriate time span, exposed the worker to asbestos dust thereby creating or increasing the risk that the worker would contract that disease, authority permits the conclusion that that employer caused, in the sense of materially contributed to, the worker's condition. In Naxakis v Western General Hospital (1999) 73 ALJR 782 at 787 Gaudron J said: "There is, in my view, a tendency to exaggerate the difficulties associated with proof of causation, even in medical negligence cases. For the purposes of the allocation of legal responsibility, '[i]f a wrongful act or omission results in an increased risk of injury to the plaintiff and that risk eventuates, the defendant's conduct has materially contributed to the injury that the plaintiff suffers whether or not other factors also contributed to that injury occurring' Chappel v Hart (1998) 72 ALJR 1344 at 1350 per McHugh J. And in that situation, the trier of fact - in this case, a jury - is entitled to conclude that the act or omission caused the injury in question unless the defendant establishes that the conduct had no effect at all or that the risk would have eventuated and resulted in the damage in question in any event."

At 806-7 Callinan J also cited this passage from the judgment of McHugh J. 24 But evidence of negligent exposure to risk from asbestos dust and evidence that the worker contracted a condition, which could have been caused by asbestos dust, rather than evidence that the condition was caused by asbestos dust, presents a different problem. In this case the Board argues that the only evidence of causation was statistical evidence and fell within the first of these categories. 25 There could be no doubt that Mr Scates's employment at the Tamworth Power Station materially increased the risk that he would contract lung cancer. In Commissioner for Government Transport v Adamcik (1961) 106 CLR 292 a case to which Powell JA drew our attention, a medical practitioner called on behalf of the widow of a deceased employee gave evidence that in his opinion physical injuries sustained by the deceased together with the mental stress accompanying them had caused leukaemia as a result of which the deceased died. In the widow's claim under the Compensation to Relatives Act against the employer, the jury found a verdict for the plaintiff. There was contrary medical evidence of no connection between the accident and the leukaemia. By a majority the High Court dismissed an appeal from the Full Court of the Supreme Court which had dismissed an application to have the verdict set aside. Windeyer J, with whose judgment Kitto J agreed, said at 309, after referring to Blackstock v Foster [1958] SR (NSW) 341: "That case was thus quite unlike this, where a medical witness said that the onset of leukaemia was not only possibly but more probably than not the result of the accident. …. It is not enough that we may think the jury's verdict was wrong." 26 In the present case there was medical evidence that the exposure of Mr Scates to asbestos dust materially contributed to the lung cancer. This being so, the application of the principle as stated by Glass JA in Azzopardi means that this appeal in truth does not raise a point of law but is against the trial Judge's findings of fact. Accordingly, the appeal is incompetent. 27 In my opinion, the appeal should be dismissed with costs. 28 POWELL JA: I agree with Sheller JA. 29 ROLFE AJA: I agree with Sheller JA.

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