Reported Decision : (2001) 50 NSWLR 729 (2001) 21 NSWCCR 436 New South Wales Court of Appeal CITATION : Government Insurance Office of New South Wales v Colgate Palmolive Pty Ltd [2001] NSWCA 24 FILE NUMBER(S) : CA 41007/99 HEARING DATE(S) : 29 January 2001 JUDGMENT DATE : 22 February 2001 PARTIES : Government Insurance Office of New South Wales (Appellant) Colgate Palmolive Pty Ltd (Respondent) JUDGMENT OF : Priestley JA at 1; Sheller JA at 2; Heydon JA at 3 LOWER COURT JURISDICTION : Dust Diseases Tribunal LOWER COURT DDT 118/90 FILE NUMBER(S) : LOWER COURT Curtis J JUDICIAL OFFICER : COUNSEL : G F Little SC/N E Chen (Appellant) C R R Hoeben SC (Respondent) SOLICITORS : Sparke Helmore (Appellant) Barker Gosling (Respondent) CATCHWORDS : Workers Compensation - "Occupational diseases" - Nature of employment to which diseases due - Employment risks - Gradual progression of diseases - Cumulative causes and aggravation of diseases over time - Liability of employer - Indemnification by insurer - Multiple insurers - Identification of liable insurer - Relevance of actual causation to insurers' liability - Relevance of mere risk of causation to insurers' liability - Liability consequences of triggering common and uncommon latent conditions - Effect of smoking on risk of contracting disease - Relevance of smoking to liability - Workers Compensation Act 1987, s 151AB. D Dust Diseases Tribunal Act 1989 LEGISLATION CITED : Workers Compensation Act 1926 Workers Compensation Act 1987 Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 Blatchford v Staddon and Founds [1927] AC 461 CIC Workers Compensation (NSW) Ltd v Alcan Australia Ltd (1994) 35 NSWLR 169 CIC Workers Compensation (NSW) Ltd v Kellogg (Australia) Pty Ltd (1996) 40 NSWLR 422 Coal & Allied Operations Pty Ltd v Collins (1989) 5 NSWCCR 218 Commonwealth v Bourne (1960) 104 CLR 32 CASES CITED: Commonwealth v Rutledge (1964) 111 CLR 1 Commonwealth v Thompson (1960) 104 CLR 48 Connair Pty Ltd v Frederiksen (1979) 53 ALJR 505 FAI Traders Insurance Co Ltd v HIH Winterthur Workers Compensation (NSW) Pty Ltd (1998) 45 NSWLR 257 GIO General Limited v ABB Installation & Service Pty Ltd (2000) 19 NSWCCR 720 MMI Insurance Compensation (NSW) Ltd v Baker (1997) 41 NSWLR 289 Smith v Mann (1932) 47 CLR 426 WorkCover Authority of New South Wales v Chubb Australia Ltd [2000] NSWCA 221 DECISION : Appeal dismissed; the appellant is to pay the respondent's costs of the appeal THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 41007/99 DDT 118/90 PRIESTLEY JA SHELLER JA HEYDON JA 22 February 2001 GOVERNMENT INSURANCE OFFICE OF NEW SOUTH WALES v COLGATE PALMOLIVE PTY LTD Workers Compensation - "Occupational diseases" - Nature of employment to which diseases due - Employment risks - Gradual progression of diseases - Cumulative causes and aggravation of diseases over time - Liability of employer - Indemnification by insurer - Multiple insurers - Identification of liable insurer - Relevance of actual causation to insurers' liability - Relevance of mere risk of causation to insurers' liability - Liability consequences of triggering common and uncommon latent conditions - Effect of smoking on risk of contracting disease - Relevance of smoking to liability - Workers Compensation Act 1987, s 151AB. The plaintiff at first instance before the Dust Diseases Tribunal (the Tribunal) was employed from 1966 to 1991 by Colgate Palmolive Pty Ltd (the defendant before the Tribunal and the respondent to this appeal). In the course of the early period of that employment (1967 to 1970) the plaintiff was exposed to enzymes, and as a result he contracted asthma, bronchitis and emphysema. The plaintiff had a predisposition to these diseases due to his smoking. The plaintiff's condition was materially aggravated in a cumulative fashion by exposure to welding fumes during the latter part of his employment with the respondent (1972 to 1988). The appellant (the Government Insurance Office of NSW) was the respondent's insurer from 1 January to 30 June 1987. The respondent, as the defendant employer, was found liable by the Tribunal for damages for the plaintiff's diseases. The appellant was ordered under s 151AB of the Workers Compensation Act 1987 (NSW) to indemnify the respondent for the payment of those damages. This is an appeal against that order for error of law. Section 151AB of the Workers Compensation Act provides as follows: "(1) If an employer is liable independently of the Act for damages for an occupational disease contracted by a worker, the following provisions have effect for the purpose of identifying from among a number of insurers under policies of insurance obtained by the employer for different periods which insurer or insurers is liable to indemnify the employer for the full amount of the damages or which is liable to pay the full amount of damages to the worker (without any right to contribution from those other insurers): (a) Any liability of that employer that arose before [30 June 1987] is taken to have arisen when the worker was last employed before that commencement by that employer in an employment to the nature of which the disease was due." Held by Heydon JA (Priestley and Sheller JJA concurring), dismissing the appeal: 1. Section 151AB (1)(a) is concerned with exposure to a risk which might cause the disease, and is not concerned with causation in fact. GIO General Insurance Ltd v ABB Installation & Service Pty Ltd (2000) 19 NSWCCR 720 (followed). 2. The trial judge did not err in law in finding that the welding was causative in relation to the plaintiff's diseases. (a) Despite the generality of expert evidence given at trial in relation to causation and aggravation of the diseases, the evidence was still capable of supporting the trial judge's conclusion. Consideration of the strength of this evidence was a factual process and therefore any errors in this process were not errors of law. As these findings were "primary findings of fact", rather than "ultimate findings of fact", the trial judge's misapplication of the legal test in their regard does not vitiate them. Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139, referred to. (b) It had not been shown that the trial judge misunderstood the expert evidence. (c) In any event, the trial judge's findings of actual causation in relation to the welding exceeded what it was necessary to decide for the employer to be successful. 3. It is not relevant to ascertain to which exposure (earlier or later) the diseases were due. The expression "occupational disease" in s 151AB(1)(a) is not confined to the first contraction of the disease, but can apply to the disease as it progresses. In relation to cumulative causes and the progression of diseases, the facts of GIO General Insurance Ltd v ABB Installation & Service Pty Ltd (applied) are on all fours with the facts of this case. 4. The trial judge did not err in law in finding that the plaintiff's employment was one "to the nature of which the diseases were due", since there existed evidence to support this finding. The fact that the plaintiff smoked does not derogate from this finding because (a) some evidence demonstrated a risk of the plaintiff's diseases to welders regardless of smoking, (b) "employers must take employees as they find them" and it is common knowledge that many manual workers smoked between 1966 and 1984, (c) even if smoking was not common in such employees at this time, the triggering of uncommon latent conditions is no bar to workers compensation claims. Cth v Rutledge (1964) 111 CLR 1, Connair Pty Ltd v Frederiksen (1979) 53 ALJR 505 and Cola & Allied Operations Pty Ltd v Collins (1989) 5 NSWCCR 218, referred to. 5. The trial judge did not err in finding that the plaintiff was suffering from an "occupational disease". To be an "occupational disease", a disease need not be the "ordinary result" of the employment. This would impose an unnecessarily heavy evidentiary burden on litigants. In any event, the appellant did not prove that the plaintiff's diseases were not the "ordinary result" of his employment in this case. GIO General Insurance Ltd v ABB Installation & Service Pty Ltd, CIC Workers' Compensation (NSW) Ltd v Alcan Australia Ltd (1994) 35 NSWLR 169, Cth v Thompson (1960) 104 CLR 48 and Connair Pty Ltd v Frederiksen (1979) 53 ALJR 505, referred to. 6. The trial judge did not err in law in finding that the plaintiff was not suffering from two distinct occupational diseases. The plaintiff's lung diseases are not analogous to an industrial deafness claim where there exists a "succession of completed tortious insults". WorkCover Authority of New South Wales v Chubb Australia Ltd [2000] NSWCCA 221, referred to. ORDERS: 1. Appeal dismissed. 2. Appellant to pay respondent's costs of the appeal. THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL CA 41007/99 DDT 118/90 PRIESTLEY JA SHELLER JA HEYDON JA 22 February 2001 GOVERNMENT INSURANCE OFFICE OF NEW SOUTH WALES v COLGATE PALMOLIVE PTY LTD JUDGMENT 1 PRIESTLEY JA: I agree with Heydon JA. 2 SHELLER JA: I agree with Heydon JA 3 HEYDON JA: Background This is an appeal by the Government Insurance Office of New South Wales ("the GIO") against an order made by Judge Curtis in the Dust Diseases Tribunal on 3 December 1999 pursuant to s 151AB of the Workers Compensation Act 1987. He ordered the GIO to indemnify Colgate Palmolive Pty Ltd ("the employer") against its liability to the plaintiff in relation to diseases contracted while the plaintiff was employed by the employer as a fitter. The appeal only lies if an error of law can be established: Dust Diseases Tribunal Act 1989 s 32(1). 4 The primary judge made the following findings of fact. The employment commenced on 30 March 1966 and ended in November 1991. The plaintiff smoked one packet of cigarettes a day until about 1984. Between June 1967 and 1970, the plaintiff inhaled proteolitic enzymes in the course of his employment. This inhalation caused the plaintiff to contract asthma, bronchitis and emphysema, these being diseases to which he was predisposed because of his smoking (Red 105W-106E). Between 1972 and 1988 the plaintiff performed welding work in the course of his employment. This exposed him to harmful fumes. Between 1972 and 1986 the plaintiff spent 15-20% of his working hours welding. Between 1986 and June 1987 he spent about 5% of his time in this way. The fumes from the welding work caused material aggravations of the plaintiff's asthma, bronchitis and emphysema. Because of the fumes, the welding work was of a nature capable of causing the diseases had they not already been present in the plaintiff's lungs (Red 106V-107E). The plaintiff's work between January 1987 and 30 June 1987 was employment to the nature of which the diseases of asthma, bronchitis and emphysema may be due (Red 108F). Welding is an employment implicated by the medical profession in the aetiology of diseases of the lung, such as those suffered by the plaintiff, because of the properties of welding fumes (Red 125L). All exposures to welding fumes were important in the progression of the plaintiff's lung diseases and the effect of those fumes was cumulative (Red 128K). The GIO was the employer's workers compensation insurer in the period 1 January-30 June 1987 (Red 107J). 5 The employer's application for indemnity was made pursuant to s 151AB. It relevantly provides: "(1) If an employer is liable independently of this Act for damages for an occupational disease contracted by a worker, the following provisions have effect for the purpose of identifying from among a number of insurers under policies of insurance obtained by the employer for different periods which insurer or insurers is liable to indemnify the employer for the full amount of the damages or which is liable to pay the full amount of damages to the worker (without any right to contribution from those other insurers). (a) Any liability of that employer that arose before [30 June 1987] is taken to have arisen when the worker was last employed before that commencement by that employer in an employment to the nature of which the disease was due." 6 The provision contemplates identification of one among a number of insurers. At one time five insurers were involved in the present proceedings. The proceedings were instituted by the plaintiff against the employer; the employer then made its application for indemnity under s 151AB by a document entitled "First Cross-Claim", to which five insurers were joined as cross-defendants. Of these, the GIO was the fifth. There were no cross- claims among the insurers. When the hearing began on 10 May 1999, counsel for the employer informed the trial judge that it had discontinued the First Cross-Claim against the second, third and fourth cross-defendants (Black 2K). Counsel for the employer also said: "we have got the last insurer on the basis of welding fumes and an earlier insurer on the basis of enzyme dust". That was a shorthand reference to the exposure of the plaintiff to welding fumes while the GIO was the insurer in the first six months of 1987 and to the exposure of the plaintiff to enzyme dust in 1967-1970, while Monarch Insurance Co Ltd ("Monarch") was the insurer. On 12 May 1999 counsel for the employer sought leave to discontinue the First Cross-Claim as against Monarch without opposition from Monarch, but the trial judge postponed the making of any orders (Black 165L-O). There was material in the file indicating the possibility that that leave was granted on 20 May 1999, though the parties did not cast light on whether it was. That possibility receives further support from the fact that on 18 October 1999 the trial judge stated the view that Monarch had ceased to be a cross-defendant (Black 179H). At the hearing of the appeal, after some doubt was expressed about the status of Monarch, counsel for the employer agreed to resolve the doubt by undertaking to the Court to file a consent order recording a discontinuance with effect from 20 May 1999. The Construction of s 151AB(1)(a) 7 In GIO General Limited v ABB Installation & Service Pty Ltd (2000) 19 NSWCCR 720, this Court reviewed four of its own authorities, namely CIC Workers' Compensation (NSW) Ltd v Alcan Australia Ltd (1994) 35 NSWLR 169; CIC Workers Compensation (NSW) Ltd v Kellogg (Australia) Pty Ltd (1996) 40 NSWLR 422; MMI Insurance Compensation (NSW) Ltd v Baker (1997) 41 NSWLR 289 and FAI Traders Insurance Co Ltd v HIH Winterthur Workers Compensation (NSW) Pty Ltd (1998) 45 NSWLR 257. At 726, para 19, it concluded that the effect of those and earlier cases was that: "s 151AB(1)(a) is not concerned with causation in fact. Rather, it is concerned with exposure to a risk which may be causative of the disease." To use the words of Gibbs J in another context in Connair Pty Ltd v Frederiksen (1979) 53 ALJR 505 at 508-9, the inquiry is into whether the employment under consideration had an "incident, aspect or characteristic" which "would be expected to occur in employment of that class" and which carried a risk which was potentially causative of the disease suffered by the relevant employee. 8 GIO General Ltd v ABB Installation & Service Pty Ltd was decided after the trial judge's reasons for judgment were delivered. No application was made by the GIO for leave to re-argue its correctness, though on occasion its arguments approached or arrived at inconsistency with it. In the absence of any application for leave, that authority must obviously be treated as correct and, so far as relevant, applied. The Trial Judge's Approach 9 The trial judge approached the issues in the light of his reading of two of the cases analysed in GIO General Ltd v ABB Installation & Service Pty Ltd. He considered that MMI Insurance Compensation (NSW) Ltd v Baker (1997) 41 NSWLR 289 at 294 supported the following construction of s 151AB (Red 120U-W): "s 151AB is no longer wholly concerned with an abstract inquiry as to the nature of employment at a particular time. Before that inquiry is made the Court must first determine the concrete facts of causation and breach of duty in the particular case". He evidently considered that FAI Traders Insurance Co Ltd v HIH Winterthur Workers Compensation (NSW) Pty Ltd supported that conclusion also (Red 121W-122T). 10 The trial judge then said (Red 123F-L and 124M-O): "It is necessary to the operation of s 151AB that the Tribunal ascertain the last causal breach of duty in order to identify the last insurer 'contractually liable to indemnify the employer' in respect of the employer's liability in damages for injury caused by those breaches. No later insurer is at risk. The issues to be canvassed in such an inquiry are no longer confined to the nature of the employment in the abstract but extend to considerations of whether the employer at a particular time was in breach of his duty to take reasonable precautions to protect the worker from the hazards inherent in employment of a particular nature and whether those breaches were causally relevant to the plaintiff's injuries so as to give rise to a liability against which a particular insurer has promised indemnity. … In any event I am bound by the decisions in MMI v Baker and FAI v HIH . In the application of s 151AB to the present facts, I must determine the time at which, in consequence of his employer's breach of duty, the plaintiff last became entitled to damages as a result of a material aggravation of an occupational disease in an employment to the nature of which his disease was due." 11 The trial judge found that these tests were satisfied. 12 Neither MMI Insurance Compensation (NSW) Ltd v Baker nor FAI Traders Insurance Co Ltd v HIH Winterthur Workers Compensation (NSW) Pty Ltd supports the trial judge's approach. In any event, GIO General Ltd v ABB Installation & Service Pty Ltd held that both cases were immaterial on the question of what construction s 151AB(1)(a) bore. Of MMI Insurance Compensation (NSW) Ltd v Baker, the Court said ((2000) 19 NSWCCR 720 at 728-9, paras 27-29): "In that case, the worker sued his employer for hearing loss caused by exposure to noise in the course of his employment. Although the worker remained in the same employment until 1990, he confined his claim to injury sustained prior to 30 June 1987, so as to preserve his common law rights to damages. Amendments to the Act in 1987 and 1989 had altered the rights of workers to claim both. Gleeson CJ (Meagher and Powell JJA agreeing) described the purpose of s 151AB at 293 as being: [r]elated to a case where there are two or more policies of insurance under which an employer is contractually entitled to indemnity in respect of damages for which a plaintiff sues . (Emphasis added.) As the plaintiff had confined his claim to the period prior to 30 June 1987, during which time there was only one insurer, s 151AB had no application. Baker therefore has little to say in relation to the case under appeal." 13 Of FAI Traders Insurance Co Ltd v HIH Winterthur Workers Compensation (NSW) Pty Ltd, the Court said (at 729-730, paras 30-31): "That case also involved a deafness claim confined to the period prior to 30 June 1987, although the plaintiff had continued in a noisy employment with the same employer after that date. The appellant, who was the insurer on risk for the period 1 September 1986 to 30 June 1987, was held liable to indemnify the employer. On the appeal, the appellant sought to have the respondent, who was on risk for the period 30 June 1995 to the date of hearing, made liable to indemnify the employer. Handley JA (Fitzgerald JA in a separate judgment and Sheppard A-JA agreeing) held that the case was governed directly by the decision of the Court in Baker . His Honour added at 261: If the plaintiff had persisted in his claim to recover damages for industrial deafness caused by his noise exposure after 30 June 1987, another insurer may have become liable for the whole of those damages. However, in all probability the plaintiff would not have recovered any damages for his noise exposure after 30 June 1987 because of the restrictions in Div 3 of Pt 5 of the Act: see s 151U(1) and Div 3. If so the only damages awarded would have been for the period up to 30 June 1987 and the appellant would have been the insurer liable. " 14 The Court concluded (at 730, para 32): "The construction of s 151AB has, in our opinion, been decided by this Court in Alcan . Kellogg is relevant to this case as it defines employment so as to extend beyond merely the work tasks performed. However, to the extent that Baker and HIH deal with claims made in artificially confined periods, they do not apply to this case." 15 In the light of GIO General Ltd v ABB Installation & Service Pty Ltd, the employer filed a Notice of Contention in the following terms: "For the operation of s.151AB of the Workers Compensation Act 1987, the issues to be considered … do not extend to considerations of whether the employer at a particular time was in breach of its duties to take reasonable precautions to protect the worker from the hazards inherent in employment of a particular nature and whether those breaches were causally relevant to the Plaintiff's injury so as to give rise to a liability against which a particular insurer has promised indemnity." The following paragraph appeared in the GIO's written submissions (para 18): "Subject to the above submission concerning the industrial deafness type circumstance (which it is submitted applies to the enzyme exposure) the appellant accepts that the position as stated in the Notice of Contention with regard to the occupational diseases is correct." 16 The submission referred to, which is considered in paragraphs 64-69 below, was to the effect that the exposure to enzyme dust in 1967-1970 was analogous to an industrial deafness claim and therefore outside the reasoning in GIO General Ltd v ABB Installation & Service Pty Ltd. The GIO sought to distinguish that case rather than to attack it. It follows from this shared stance of the parties that so far as the trial judge found that the employment in January-June 1987 had in fact materially aggravated the occupational diseases from which the plaintiff was already suffering, he was going further than it was necessary to go in order to decide the case in favour of the employer. And so far as the appellant's submissions on appeal seek to attack the reasoning of the trial judge to the extent that it goes beyond what was necessary to decide the case, they are not decisive. The Trial Judge's Findings of Exposure to a Risk Which Might Have Been Causative 17 It is convenient to set out the precise words of the trial judge's key findings. First he said (Red 106C-L): "Between June 1967 and some time in 1970 the plaintiff inhaled proteolitic enzymes, a component of soap powder, in the course of his employment. This inhalation caused in him the diseases of asthma, bronchitis and emphysema to which diseases he was predisposed because of his smoking. Asthma is a disease of the lung characterised by increased responsiveness of the airways to various stimuli and manifested by wide spread airways narrowing that changes in severity either spontaneously or in response to inspired matter. Bronchitis is chronic inflammation of the small airways of the lung. Emphysema is a disease characterised by abnormal enlargement of, and destruction of the walls of the alveoli, loss of lung elasticity and narrowing of the small airways leading to the alveoli. The combined effect of these diseases was to gradually and seriously reduce the plaintiff's breathing capacity and it is not possible to separate out the effect each disease has upon his disablement." 18 Then the trial judge said (Red 106V-107G): "Colgate required of [the plaintiff] that he perform welding work, exposing him to harmful fumes between 1972 and 1988. Between 1972 and 1986 he spent 15-20 per cent of his working hours welding. Between 1986 and June of 1987 that percentage was approximately five per cent because of changes in his duties. Welding fumes caused material aggravations of his diseases of asthma, bronchitis and emphysema. The work, because of these fumes, was of such a nature as to be capable of causing each of these diseases had they not been already present in the plaintiff's lungs." 19 The trial judge said (Red 107J-K): "The cross defendant came on risk on 1 January 1987. On 20 January 1987 the plaintiff suffered an acute attack of breathing difficulty while welding in a sulphur pit, illustrative of the effects of welding fumes upon his underlying condition. The immediate effects of this episode were transient." 20 The trial judge said (Red 108F-I): "Accepting that the plaintiff's work between January 1987 and 30 June 1987 was, in the abstract, employment to the nature of which the diseases of asthma, bronchitis and emphysema may be due, there is no evidence specifically directed to the question of whether the work in that short period materially contributed to the injuries for which the plaintiff recovered damages. I must rely on inference." 21 The trial judge also said (Red 125K-M): "Welding is generally an employment which has been implicated by the medical profession in the aetiology of diseases of the lung such as those suffered by the plaintiff because of the properties of welding fumes." 22 The trial judge then said (Red 126M-128O): "The evidence sufficient to discharge the onus on Colgate is to be found in that opinion of Professor Bryant at p27 of the transcript [Blue 207B-U] as follows: Q. Just looking, not specifically at Mr Greniewicz but at the general proposition, can welding fumes in combination with a history of smoking, are they capable of causing occupational asthma. A. I believe they are. Q. Again, a person who is exposed to welding fumes in combination with a history of smoking, is that combination capable of causing bronchial disease of bronchitis. A. I believe it is. Q. Finally, the history of exposure to welding fumes and a history of smoking, is that capable of causing a person emphysema. A. Yes. Q. I take it from those answers, professor, that that combination would also be capable in a general sense of aggravating those conditions if they pre-existed in a particular person. A. I agree with that proposition too. Q. Have you had occasion, professor, to study a situation where somebody with a pre-existing lung problem, be it asthma or be it emphysema is then exposed subsequently to welding fumes and as to whether or not that has an increasing effect or an increasingly deleterious effect on a person. A. I can't say whether it's got an increasingly deleterious effect but I certainly have seen patients in whom there has been a deleterious effect which appears to date from the time that the welding commenced. Q. Have you found that that effect becomes irreversible if a history of exposure to welding fumes is over a considerable period of time. A. Usually that effect is irreversible. HIS HONOUR: What is a considerable period? MR HOEBEN: That is my next question, your Honour. Q. Doctor, would you regard a period in excess of 10 years as being - A. I would regard a period in excess of several years. Q. Even if a person was perhaps not spending all of his or her time welding but perhaps only spending 20 per cent of their time welding, would you still regard a period of at least 10 years as being a sufficient period of time to cause an irreversible effect. A. In my experience, yes. Q. Again looking at the question generally and without focusing particularly on Mr Greniewicz, are all exposures to welding fumes contributory or is one able to separate various periods. A. I think that would be very difficult to do, in general terms I would assess that all are important and it's a cumulative effect. Q. If included in exposures there were in a history instances of what could be perhaps described or characterised as acute exposures, that is somebody working for 7 or 8 hours in a confined space doing stainless steel welding and leaving that particular job with a runny nose and quite irritated, would that sort of exposure have a contributory effect. A. Periods of high exposure are more likely to result in acute symptoms and long term disability than is longer periods of lower level of exposure although both are probably important. … GIO in cross examination did not suggest to the professor that his opinions were wrong. [GIO] called no medical evidence. In that circumstance I accept the evidence of Professor Bryant that all exposures to welding fumes were important in the progression of the plaintiff's lung diseases and that the effect of these fumes has been cumulative. If GIO were to assert that the very short period of exposure between January and June of 1987 was in all the circumstances de minimis then it ought to have put that to Professor Bryant and called medical evidence to support such an assertion." These findings that all exposures to welding fumes were important in the progression of the plaintiff's lung diseases and that the effect of the fumes has been cumulative imply a finding that the exposure from January to July 1987 was important. 23 Finally, the trial judge said (Red 128Q-V): "I find that the liability of Colgate Palmolive Pty Ltd to pay damages to Mr Greniewicz in respect of the occupational diseases contracted by him in the course of his employment with Colgate Palmolive Pty Ltd arose on 30 June 1987. I find that the Government Insurance Office of New South Wales was the insurer liable to indemnify Colgate Palmolive Pty Ltd in respect of this liability." 24 These findings, expressly or by implication, indicate that the trial judge was of the following opinions: (a) the employer was liable independently of the Workers Compensation Act for damages for diseases contracted by the plaintiff; (b) those diseases were "occupational diseases", that is, diseases "of such a nature as to be contracted by a gradual process": s 151AB(6); (c) the employment of the plaintiff in the period 1 January-30 June 1987 was an employment "to the nature of which the [diseases were] due". Structure of the Argument 25 It is convenient to deal with the GIO's arguments generally in the order in which they were advanced in writing, though the oral order was different, and some aspects of the GIO's case emerged more clearly in oral debate. Was the Trial Judge Correct in Concluding That In Fact the 1 January-30 June 1987 Exposure to Welding Fumes Caused Any Part of the Plaintiff's Diseases? 26 The GIO drew attention to the following finding of the trial judge (Red 128I-L): "all exposures to welding fumes were important in the progression of the plaintiff's lung diseases and … the effect of these fumes has been cumulative". The GIO put the following submission (para 8): "The evidence Judge Curtis purported to rely on to support this finding - that of Professor Bryant - was general evidence without regard to the particular circumstances of the plaintiff's employment with Colgate (RB126O-128H). His Honour's reliance on the 'evidence' of Professor Bryant proceeded upon a misunderstanding of the evidence given. There was no evidence to support the finding of causation made by Judge Curtis and his Honour was in error in so finding: see generally Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139." 27 The employer responded in the following terms (para 12): "There was unchallenged evidence as to exposure by the plaintiff to welding fumes between January and 30 June 1987. An example of that evidence is to be found at RB107J-K [quoted above]. The unchallenged evidence of Professor Bryant at RB126M-RB128H was to the effect that such exposure was capable of causing and aggravating the conditions of asthma, bronchitis and emphysema. That is all which had to be established under s.151AB. A no evidence point on this issue is not available to the appellant." 28 The GIO's submissions in effect make two complaints. 29 The first complaint was that Professor Bryant's evidence was incapable of supporting the findings because it was general. The fact that it was general, not being linked to the particular circumstances of the plaintiff's employment, does not deprive it of its status as evidence capable of supporting the trial judge's conclusion. Assessment of the strength of the evidence was a factual process; if there was error in that assessment, it was an error of fact and not of law. The trial judge's misdirection of himself as to the legal test to be applied was, apart from being excessively favourable to the GIO, not relevant to the findings under consideration: they were "primary findings of fact", not "ultimate findings of fact" in the sense used by Glass JA in Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 at 156C, and misdirection in law vitiates only ultimate findings. In the oral argument the GIO appeared to withdraw this complaint: Transcript p 14 lines 16-17. 30 The second complaint of the GIO was that the trial judge misunderstood Professor Bryant's evidence. Neither the written nor the oral submissions identified or articulated that misunderstanding. In these circumstances it is not possible to accept the submission. 31 In any event the trial judge's findings of actual causation went beyond what it was necessary to decide if the employer were to succeed. However, they were made, and the consequence of them having been made is that it would normally follow from the finding that the exposure to fumes in January-June 1987 caused the diseases, that this exposure carried a risk of causing the diseases. The GIO sought to avoid this consequence by contending that the risk must be the "ordinary" result of the employment. That submission is rejected for the reasons given in paras 55-63 below. Were the Diseases "Due" to the Enzyme Exposure in 1967-1970 or to the Later Fumes Exposure? 32 The GIO put the following submissions (para 10-12): "Judge Curtis found that between ' June 1967 and some time in 1970 the plaintiff inhaled proteolytic enzymes, a component of soap powder, in the course of his employment. This inhalation caused in him the diseases of asthma, bronchitis and emphysema to which diseases he was predisposed because of his smoking' (RB106B-E). This finding necessarily establishes that the three diseases were contracted in an employment which exposed the plaintiff to proteolytic enzymes. This exposure was the incident of the employment to which the disease was due . The enquiry required by this subsection is to ascertain the nature of the employment to which the disease was due. That has been determined by his Honour to be the exposure to enzymes (RB106D-F). The plaintiff was not exposed to 'a risk which may be causative of the disease' because, as Judge Curtis found, the plaintiff's disease was caused by exposure - which ceased in 1970 - to soap enzymes: see WorkCover Authority of NSW v Chubb Australia Ltd & Ors (2000) NSWCA 221. The approach in Chubb is consistent with authorities. In Smith v Mann (1932) 47 CLR 426, Dixon J said (p440): 'The description of the disease implied in the expression in the second paragraph 'employment to the nature of which the disease was due' may properly be carried back into the first paragraph for the purpose of understanding [its] meaning. In other words the diseases dealt with are those which are contracted by a gradual process and are due to the nature of an employment'. Likewise in Tarne v Commonwealth Collieries Pty Ltd (1947) SR (NSW) 269, Jordan CJ at 272 said: 'I think that 'employment to the nature of which the disease was due' means an employment of such a kind as to involve a risk to the employee contracting the gradual process disease …'. In this case the plaintiff was not exposed to a risk of contracting a disease: the plaintiff, upon all the evidence, contracted the diseases which were caused - and well advanced - by the time GIO came on risk. The section directs attention to whether the disease was due to the employment, not whether the employment aggravated or accelerated the 'disease'. Neither the section - and the historical reasons for its introduction into workers compensation legislation - nor the authorities just cited support the approach of Judge Curtis." 33 This submission treats the incurring of the diseases as one thing and their aggravation as another. It contends that they were caused by enzymes. As the oral argument put it, though the welding fumes "aggravated" the diseases and "worsened" them, the application of s 151AB(1)(a) does not turn on aggravation and worsening but on identification of the "employment to the nature of which the disease was due". 34 The submission has the following difficulties. 35 First, although the GIO accepted the correctness of GIO General Ltd v ABB Installation & Service Pty Ltd, the submission rests on the construction rejected in that case. It looks to what actually caused the diseases. It does not look to what aspects of the employment carried a risk of the occurrence of the diseases. Even if the distinction between the initial causation of the diseases and their later aggravation were sound, the true inquiry into whether the employment was "an employment to the nature of which the disease was due" turns on potentiality, not actuality. In that respect, the trial judge made a crucial finding about the employer's requirement that the plaintiff do welding work generating fumes (Red 107E-F): "The work, because of these fumes, was of such a nature as to be capable of causing each of these diseases had they not been already present in the plaintiff's lungs". That is a finding, assuming it to be supported by evidence, which is sufficient support for the trial judge's conclusion that the employer's liability arose on 30 June 1987. It was supported by evidence: paras 40-43 below. And it is a finding of fact: Coal & Allied Operations Pty Ltd v Collins (1989) 5 NSWCCR 218 at 225 per Meagher JA (Mahoney JA concurring). 36 Secondly, there is considerable artificiality in contrasting the incurring of diseases in 1967-1970 by reason of one cause with their aggravation in later periods by reason of another. The words "occupational disease" as used in s 151AB(1)(a) are not limited to the time at which it can first be said that the disease has been contracted. They can extend to the disease as it progresses. An "occupational disease" is, by definition, "a disease of such a nature as to be contracted by a gradual process". The "disease" referred to at the end of s 151AB(1)(a) is the "occupational disease" for which the employer is liable independently of the Act. The plaintiff's proceedings commenced in 1990. In his Amended Statement of Claim the plaintiff alleged "injury, loss and damage" from welding fumes and enzymes between "1966 and approximately 1987" (Red 1S). The particulars of injury were (Red 4D-G): "(a) Severe emphysema (b) Chronic bronchitis (c) Asthma." The plaintiff's proceedings against the employer were settled on 12 May 1999 by judgment in favour of the plaintiff in the sum of $250,000 (Black 176M-P). There was no challenge by the GIO to the reasonableness of that settlement. The "occupational diseases" in relation to which the plaintiff recovered by reason of the employer's admission of liability and settlement with the plaintiff were not limited to those diseases as they had advanced by 1970. The plaintiff sued in relation to the state the diseases had reached, after gradual processes, in 1987. The processes of those diseases were not complete at the moment of initial diagnosis. They had reached a more fully developed stage by 30 June 1987, partly of their own force, partly because of the plaintiff's welding work, and probably partly because of the plaintiff's smoking. 37 Thirdly, the GIO's submission assumes that s 151AB(1)(a) is to be applied only at the moment when it is established that the plaintiff began to suffer from an occupational disease: once that moment has arrived, there is no need to consider circumstances at any later point in time. That approach is inconsistent with the mandate of s 151AB(1)(a), as construed in GIO General Ltd v ABB Installation & Service Pty Ltd, to identify the moment when the employee was last employed before 30 June 1987 "in an employment to the nature of which the disease was due", that is, an employment which in its nature was capable of creating the risk of the employee incurring the disease. That may well be a time well after the moment when the plaintiff first began to suffer from the disease. 38 Fourthly, the circumstances of the present case do not appear to be distinguishable from those of GIO General Ltd v ABB Installation & Service Pty Ltd. There the plaintiff was exposed to asbestos in 1966-1969, and this was causative of the mesothelioma from which in 1995 he was diagnosed as suffering. On two further occasions, in October 1986 and December 1986, the plaintiff was exposed to asbestos. The trial judge found that the last occasion on which the plaintiff was exposed to the risk of inhaling asbestos fibres was December 1986 (but did not find that he actually inhaled fibres). The trial judge concluded that the plaintiff was last employed in "an employment to the nature of which the disease mesothelioma was due in 1986" ((2000) 19 NSWCCR 720 at 724, para 10). If the suggested distinction between the moment when the occupational disease is contracted and any later moment at which the nature of the employment carried a risk of the disease were sound, the appeal should have been allowed. Yet this Court dismissed the appeal. Was There Evidence to Support the Trial Judge's Finding That the Plaintiff's Employment Was An Employment To the Nature of Which the Diseases were due? 39 The GIO submitted (para 13): "In determining whether the plaintiff's employment with Colgate was, in the abstract, an employment to the nature of which the plaintiff's disease was due, Judge Curtis found that welding was ' generally an employment which has been implicated by the medical profession in the aetiology of diseases of the lung such as those suffered by the plaintiff because of the properties of welding fumes ' (RB125K-N). Accordingly Judge Curtis was satisfied the plaintiff's employment was an employment to the nature of which the disease was due. It does not emerge, from Judge Curtis' reasons, what evidence supported this finding. The appellant contends there was no evidence to support it." 40 The employer pointed to Professor Bryant's evidence. After giving evidence that welding fumes in combination with a history of smoking were capable of causing asthma, bronchitis and emphysema, Professor Bryant was asked questions not predicated on a history of smoking. He answered one as follows (Red 127W-128C): "Q. Again looking at the question generally and without focusing particularly on Mr Greniewicz, are all exposures to welding fumes contributory or is one able to separate various periods ? A. I think that would be very difficult to do, in general terms I would assess that all are important and it's a cumulative effect." 41 The employer also pointed to other evidence from Professor Bryant and seven other experts, together with evidence of epidemiological studies. The evidence of the epidemiological studies suggested that welding increased the risk of asthma (Blue 40K and 63S, second column) and bronchitis (Blue 63K, first column). Other evidence was to the same effect for asthma (Blue 35G-R, 38W, 39H, 47U, 50G and 168Q; Black 200P, 203D-H and 207C) and bronchitis (Black 155H, 158V, 159J-N, 161C-D, 164R-S and 207D). Counsel for the employer summarised the numerous items of evidence to which he referred by saying that they established that exposure to fumes generated by welding carried a risk of bronchitis and asthma in both smokers and non-smokers, though there was evidence that in the case of emphysema the risk was found only where the patient had also smoked because the groups tested had all been smokers and it had not been possible to find a group of non-smokers to test. Some medical evidence not based on tests supported a risk of emphysema flowing from welding (e.g. Black 155G, 159K, 163S-U, 207F; Blue 23M-P; cf Blue 37K). 42 Dr Mann said (Blue 8K-L) "I would not expect that any continuing dust exposure would lead to any worsening of his emphysema but naturally there should never be any further exposure to soap enzymes or to any type of welding fumes." Dr Field said (Blue 14U-W): "The evidence that welding fumes cause or aggravate emphysema is still controversial, but, personally, I feel that the weight of evidence supports at least an aggravating role. It therefore [seems] probable that Mr Greniewicz's emphysema has progressed more rapidly than one might otherwise expect because of the additional contributions of alkalase and welding fumes." Dr Burns said (Black 202O): "I believe personally that it's probable that welding fumes would aggravate emphysema, but so far it hasn't yet been proven that that's the case." Dr Burns also said (Black 202Q-R): "it's difficult to prove, because the majority of welders have been smokers and so it's been difficult to separate the two components, whereas smoking doesn't [produce] asthma and therefore it's been quite easy to distinguish those two." 43 The employer's summary of the evidence appears sound; indeed, it erred, if at all, on the side of conservatism from the employer's point of view. Further, the accuracy of the summary was not challenged by the GIO, and the GIO took no point that the trial judge's order should be altered because the evidence pointed more strongly to the risk of asthma and bronchitis than to the risk of emphysema. Rather, the GIO took two points about the evidence. 44 First, it attempted to discount the evidence by pointing to the fact that welding fumes caused an aggravation of pre-existing disease: the validity of that argument was rejected in paras 32-38 above. 45 Secondly, it attempted to discount the evidence by pointing to the fact that welding fumes caused an aggravation of pre-existing disease in smokers: this argument is rejected in paras 46-54 below. The Relevance of the Plaintiff's Smoking 46 The GIO put the following submission (paras 14-15): "Judge Curtis also sought to support this finding - that the plaintiff's employment with Colgate was an employment to the nature of which the plaintiff's disease was due - based on evidence that there was an association between the plaintiff's disease with welders who smoked (which the plaintiff did). Judge Curtis did not identify the evidence relied upon to support this finding - but there was such evidence available (see Professor Bryant's evidence referred to by Judge Curtis at RB126N-128H). However, in holding that such evidence supported the finding that the plaintiff's employment was an employment to the nature of which the plaintiff's disease was due, Judge Curtis fell into error. The nature of such error was explained in Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 by Glass JA in the following terms: ' A finding of fact … may nevertheless reveal an error of law where it appears that the trial judge has misdirected himself, ie has defined otherwise than in accordance with law the question of fact which he has to answer. … Further an ultimate finding of fact, even in the absence of a misdirection, may reveal error of law if the primary facts found are necessarily within or outside a statutory description and a contrary decision has been made … '. That the plaintiff was a smoker was irrelevant to the inquiry into whether the plaintiff's employment was an employment to the nature of which the disease was due. The words of the section direct attention to the nature of the employment and its relationship with the disease rather than how the disease was caused: see, for example, Commonwealth v Bourne (1960-61) 104 CLR 32 per Dixon CJ at 38; Menzies J at 44." 47 In the trial judge's reasons for judgment, the corresponding argument put to him was recorded thus (Red 124V-Y): "even if the plaintiff suffered a material aggravation of his disease during the period when [the GIO] was on risk, that was because of the plaintiff's unusual susceptibility to injury when welding because he was a smoker. [The GIO] relies on medical opinion that only smokers were at risk of developing occupational diseases of the lung in employment as welders." 48 The argument takes no account of the fact that some of the evidence arguably pointed to a risk of asthma and bronchitis in welders independently of smoking, and more doubtfully to a risk of emphysema in welders who had not smoked. But even if that evidence had not existed, the argument would fail. It is true that the nature of the employment must be examined. But it is a notorious fact which is not reasonably open to question and is common knowledge that at least in the period between 1966 and 1984 manual workers often smoked, some fairly heavily. This appeared to be common ground. That being so, proof of those facts is not required: Evidence Act 1995, s 144(1)(a). At least in the case of a widespread practice like smoking, employers must take employees as they find them. 49 Even if smoking had not been widespread, the triggering of latent conditions which are not common has not prevented the application of workers compensation legislation to the consequential occurrence of occupational diseases. 50 Thus in The Commonwealth v Rutledge (1964) 111 CLR 1, an employee's normal duties for about four and a half years had been to sort out and file trunkline dockets of telephone calls. Then, about a fortnight after she was directed to detect suspected malpractice by other employees in relation to bookmakers' telephone calls, she suffered a breakdown, because she was a paranoiac person who became an active psychotic person. The High Court held that the employee satisfied s 10(1) of the Commonwealth Employees' Compensation Act 1930-1959 (Cth): she was suffering from a disease which had thereby incapacitated her for work, and that disease was due to the nature of the employment in which the employee was engaged by the Commonwealth. 51 In Connair Pty Ltd v Frederiksen (1979) 53 ALJR 505 the employee was employed as a pilot. He had an obsessive and compulsive personality which predisposed him, under the stress of his duties and the stress of the 1974 Darwin cyclone, which caused him to fly longer hours, in bad weather and with heavy loads, to the development of a phobia, the principal symptom of which was a fear of flying. The question was whether that phobia was "due to the nature of the employment" in which he was employed within the meaning of s 9(1) of the Workmen's Compensation Ordinance 1949-1975 (NT). By majority the High Court held that it was. 52 Coal & Allied Operations Pty Ltd v Collins (1989) 5 NSWCCR 218 is even closer to the present, since it turned on s 7(4) of the Workers Compensation Act 1926, a precursor of, though it pursues a different policy from, s 151AB(1)(a). It made provision for contribution, in relation to what the 1987 Act terms occupational disease, between any "employers who, during the twelve months preceding a worker's incapacity, employed him in any employment to the nature of which the disease was due". An employee who, before the relevant employment, had defective hearing leaving him sensitive to further injury, made a claim for industrial deafness. A contention that s 7(4) did not apply because the applicant was "unusually sensitive to noise", and that attention should be paid to the "hypothetical average employee", not to the applicant's "individual susceptibility", was rejected. Meagher JA said (at 225-226): "I can see no valid reason in doctrine why in this field there should not operate the principle, so well established in the common law of negligence, that the employer must take the employee as he finds him. Certainly none of the cases to which we were referred is authority for the suggested doctrine. What the statute, as elucidated by the cases, requires is an enquiry into the question whether the employment was one to the nature of which the disease was due. I do not see why that does not mean that the Judge must enquire into whether the disease suffered by the particular employee, as he really is, and not as he hypothetically might be, was due to the nature of his employment. That was the approach adopted by the High Court in Rutledge's case ( supra )." Mahoney JA agreed with Meagher JA (at 219). 53 Thus Meagher JA in Coal & Allied Operations Pty Ltd v Collins explicitly rejected a submission of the kind under consideration put in a context very close to the present. The High Court in Rutledge's case and the Connair case did not take the point underlying the present submission though, if sound, it would have been available in the somewhat different context of those cases. These authorities point against the validity of the GIO's submission. 54 It might be suggested that there is a difference between the pre-existing conditions affecting the employees in the three cases just mentioned, which had arisen involuntarily, and the condition of the plaintiff's lungs caused by his voluntary acts of smoking for years. However, no argument along these lines was put and its merits, if any, need not be considered. Was the Plaintiff Suffering From an Occupational Disease? 55 The GIO propounded an argument which was more clearly articulated orally than it was in writing. In essence it was that the plaintiff's condition as at 30 June 1987 was the product of a highly unusual combination of circumstances: exposure to enzymes at one period, and exposure to fumes at another. It was submitted that the issue was whether the diseases were the "ordinary" result of the plaintiff's occupation, or "ordinarily produced" by it. It was submitted that these diseases resulted from extraordinary and abnormal factors in a "very unusual and rare case" arising from a special class of activities not characteristic of the general work of fitters. 56 The GIO did not take this Court to any judicial language specifically supporting its contention that in law the diseases (or the risk of them) had to be the ordinary result of the occupation. The GIO referred in passing to Smith v Mann (1932) 47 CLR 426. That was a case on s 7(4) of the Workers Compensation Act 1926. Starke J at 443 approved a test turning on whether the disease was "incidental" to the relevant class of employment "so that it can be attributed to service therein", but this does not support the test for which the GIO argued. Dixon J at 449 said of s 7(4): "The employer at the time of, or last before, the incapacity is made primarily liable. It seems proper to understand the provision … is confined to employers who do employ or have employed the worker in employment to the nature of which the disease is due, but any further restriction upon the class of employment or any further requirement as to causation seems unwarranted." If so, it is not warranted to restrict the causation to be looked for to that which is "ordinary". That passage in Dixon J's reasons for judgment was approved in GIO General Ltd v ABB Installation & Service Pty Ltd (2000) 19 NSWCCR 720 at 726-7, para 19. 57 Further, the authorities stress the proposition that "employment" in s 151AB(1)(a) and its precursors "refers to the work or process on which the workman had been engaged and not to his contract with an employer to engage in it": Blatchford v Staddon and Founds [1927] AC 461 at 482 per Viscount Blanesburgh, approved by this Court in CIC Workers' Compensation (NSW) Ltd v Alcan Australia Ltd (1994) 35 NSWLR 169 at 174. That latter case points against any inquiry into the ordinary consequences of being a fitter, and, when read as a whole, points towards an inquiry into whether the actual work engaged in involves a risk of contracting the disease in question without any adjectival qualification. 58 It is true that in The Commonwealth v Thompson (1960) 104 CLR 48 at 56 Windeyer J said: "For a disease to be due to the nature of the employment in which the employee was engaged, the employment must be such that it ordinarily tends to cause that disease." But the next words deprive "ordinary" of any significance as a support for the GIO's argument: "That is to say, it must be a property of that form of employment to produce that disease - so that contracting that disease can be said to be a natural result of being engaged in that employment." A result can be natural without being ordinary. 59 It is also true that in The Commonwealth v Bourne (1960) 104 CLR 32 and The Commonwealth v Thompson (1960) 104 CLR 48, the High Court held that heart disease was not due to the nature of the employment in which an investigating officer in the Taxation Department was engaged. Dixon CJ said at 39, speaking of the statutory words "due to the nature of the employment": "The word 'nature' is a wide as well as a vague word and one must be careful not to narrow its application or attempt to reduce it to too much precision. But it does seem to refer to a connection between the 'disease' in the defined sense and the description of employment in virtue of its tendencies, incidents or characteristics. The investigation of sales tax cases appears to me to have nothing in its nature to accelerate vascular and cardiac degeneration and if Bourne's employment is defined in the wider terms of an officer of the Taxation Department I know of nothing in the nature of that employment to do so." An analysis of tendencies, incidents and characteristics does not limit the inquirer to the ordinary consequence of those tendencies, incidents or characteristics. 60 Further, if the GIO's submission were correct, it would impose on employees - and indeed on employers and competing insurers under s 151AB(1)(a) - a burden which, according to Gibbs J in Connair Pty Ltd v Frederiksen (1979) 53 ALJR 505 at 508-509, was not intended. He said: "Although the test established by the English legislation was whether the disease was due to the nature of the employment, rather than whether it was due to the employment itself, the authorities are not opposed to the view that the fact that the disease was caused by the employment is in many if not most cases evidence that it was in the nature of the work to cause it. For although the eccentricities of animate behaviour may cause persons and animals to act contrary to their natures, the same is not true of employment, and when it is proved that a disease was caused by (and not merely contracted during) the employment, and it appears, either by proof or as a matter of common knowledge, that the incident, aspect or characteristic of the employment that caused the disease is one that would be expected to occur in employment of that class, it would seem to follow that the disease was due to the nature of the employment. And having regard to the objects of the legislation, and the purpose of using the words in question, it is difficult to believe that the legislature intended to place a workman under the burden of calling evidence either as to the manner in which employment of a particular kind is generally carried on by employers other than his own, or of the extent to which a particular disease is found to accompany the performance of employment of that kind." Murphy J agreed "generally" at 514. If it were necessary to establish that the relevant risk was the "ordinary" result of the employment, evidence of the type described by Gibbs J would commonly be called for. His denial of any duty to tender it points against the "ordinary result" test. 61 The same conclusion follows from a later passage. In discussing The Commonwealth v Bourne (1960) 104 CLR 32, Gibbs J said at 509: "Fullagar J., at p. 40, suggested that the workman must show that a characteristic or distinctive feature of the employment was a tendency to cause, aggravate or accelerate the disease, and added that the section only applies to cases where there is a special risk of contracting a particular disease or of suffering an aggravation or acceleration of a particular disease. He did not, however, suggest that the risk should be high, or that it was necessary that the employment should frequently or commonly cause the disease. The decision in The Commonwealth v Rutledge is opposed to any such notion, since it can hardly be suggested that a person serving as a clerical employee in the Postmaster-General's Department runs a high risk of contracting a severe psychotic disorder, or of suffering an aggravation or acceleration of an existing disorder of that kind, or that there are many cases in which service in that capacity results in mental disease. Nor is it suggested that the risk must be unique to the employment in question, and there is nothing in the words of the section to support such a suggestion." If the risk need not be high, frequent or common, it is difficult to see why it should be the "ordinary" result of the employment. 62 If the test propounded by the GIO is sound, it was not adverted to in GIO General Ltd v ABB Installation & Service Pty Ltd. That case is factually similar to the present in that the 1966-1969 exposure occurred at a power station in South Australia while the plaintiff was working next to employees doing lagging work, while the 1986 exposure took place at a Kelloggs factory in New South Wales while the plaintiff was walking around it. No inquiry was made into whether the plaintiff's condition was the result of ordinary or highly unusual circumstances. 63 Even if the legal test were that argued for by the GIO, the Court was taken to no finding of fact which could satisfy it, no request for any such finding, and no evidence specifically presented in a manner which could form the basis of such a finding. Were There Two Different Sets of Occupational Diseases? 64 The GIO submitted (paras 16 and 17(b)): "It is submitted that the enzyme exposure could be likened to the industrial deafness claims given the Judge's positive findings of date of injury and sequelae. Applying Chubb , the welding fumes could inculpate the last insurer on risk at a time when there was a last risk of exposure to such fumes, ie the GIO and the enzymes inculpate the last insurer on risk at that time in respect of the damages referable to that exposure. If it were held that the Judge's findings constituted a finding of two separate and distinct sets of occupational diseases contracted in two separate employments with the one employer, it would be necessary to assess damages for the injury caused by exposure to the proteolytic enzymes and order indemnity in respect of those damages be provided by the last insurer on risk in that employment and the balance of the damages in respect of the exposure to welding fumes employment in which case the present appellant would be the last insurer on risk in respect of those damages. It is submitted that this approach is consistent with the recent decision in WorkCover Authority of NSW v Chubb Australia Limited & Ors (2000) NSWCA 221, particularly at paragraphs 26 and 27." 65 In WorkCover Authority of New South Wales v Chubb Australia Ltd [2000] NSWCA 221 at paras 26 and 27 the Court said: "At this point, it is important to note that there is a significant difference between a closed claim for industrial deafness and a claim in respect of mesothelioma. The former is a succession of completed tortious insults whereas the latter, because of its aetiology, is not complete until the disease of mesothelioma strikes, usually many many years after the asbestos exposure. Also, one will normally not know which asbestos fibre caused the mesothelioma. It could be an asbestos fibre inhaled during any time over a lengthy period of exposure. It is this distinction which must be kept steadily in mind when approaching the instant case and examining the authorities." In oral argument the GIO submitted that the construction of s 151AB(1)(a) adopted in GIO General Ltd v ABB Installation & Service Pty Ltd did not apply where there are succeeding "closed claims", and that this was an instance of that type of case. It thus sought to distinguish that case. 66 First, the trial judge's findings do not constitute "a finding of two separate and distinct sets of occupational diseases contracted in two separate employments with the one employer". He said that the diseases were caused by enzyme inhalation, and that the welding fumes aggravated them. 67 Secondly, those findings have not been shown to be wrong. 68 Thirdly, the submission is not supported by WorkCover Authority of New South Wales v Chubb Australia Ltd at paras 26 and 27. Neither those paragraphs nor the GIO's submissions explain how it can be said that there were two separate and distinct sets of occupational diseases in the present type of case. 69 Fourthly, there is no apparent reason why the development of the plaintiff's lung diseases should be treated as being analogous to a claim for industrial deafness. The Court was not taken to any evidence specifically suggesting that there was here a "succession of completed tortious insults" or, as the submission had it, "a series of frank incidents occurring in a fairly short period of time, just like the boilermaker's deafness cases". Nor was the court taken to any evidence specifically suggesting that the diseases did anything other than gradually worsen under the influence of enzymes, smoking and fume inhalation. Orders 70 I favour the following orders: 1. Appeal dismissed. 2. The appellant is to pay the respondent's costs of the appeal. ********** DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated.