R(I) 7/98

Mr. J. G. Mitchell QC	CSI/94/1996
24.11.97
Prescribed disease D1 (pneumoconiosis) - whether dust-reticulation within definition of “pneumoconiosis”
A posthumous claim for disablement benefit was made by the claimant as the widow of her deceased husband. A medical appeal tribunal decided on the diagnosis question that at no time had the claimant suffered from prescribed disease number D1 or a sequela of that disease. The claimant appealed to the Commissioner. It was argued that the tribunal had failed to consider the statutory definition of that disease in section 122(1) of the Social Security Contributions and Benefits Act 1992 and in particular, the provision in the definition that “ “Pneumoconiosis”... includes the condition of the lungs known as dust-reticulation”.
Held, allowing the appeal, that:
1.	where a statutory definition takes the form that a relevant expression means A and includes B, it must be regarded that B is significant in the construction of the intended scope of the definition. Accordingly, dust-reticulation was to be regarded as a form of fibrosis of the lungs within the definition, whether or not it would otherwise always be medically described as constituting fibrosis;
2.	the Commissioner was entitled to have regard to the reports of the Industrial Injuries Advisory Council in construing the scope of the statutory definition (see Black-Clawson v. Papierwerke [1975] AC 591). It was apparent that the additional words relating to dust-reticulation had been deliberately retained in the definition despite the views of the Industrial Injuries Advisory Council. The retention of the words could not be ignored;
3.	the tribunal had not made it clear in their judgment that the claimant’s lungs did not exhibit a condition capable of being diagnosed as dust-reticulation within the statutory definition of pneumoconiosis.

DECISION OF THE SOCIAL SECURITY COMMISSIONER
1. 	I have decided to uphold this appeal. The decision of the medical appeal tribunal dated 16 August 1996 is erroneous in law and is set aside. The claimant’s case is referred to another tribunal for reconsideration.
2. 	This is an appeal by the claimant with leave on a question of law against the above mentioned decision of a medical appeal tribunal who made an adverse decision on the diagnosis question arising out of a posthumous claim by the claimant as the widow of her deceased husband for disablement benefit in respect of prescribed disease D1 (pneumoconiosis). The appeal was dealt with at an oral hearing attended by the claimant who was represented by Mr. T. Coulter, a retired officer of the National Union of Mineworkers. The Secretary of State was represented by Mr. Liddell, advocate, instructed by Mr Neilson acting in Scotland on behalf of the Department of Social Security. I am obliged to the representatives for their submissions in this difficult case.
3. 	The issue in the appeal before me was whether in deciding that the claimant’s late husband (“the deceased”) had not suffered from prescribed disease D1, the tribunal fell into error of law in their approach to the statutory definition of that prescribed disease. That definition is now contained in section 122(1) of the Social Security Contributions and Benefits Act 1992 and is in the following terms:
“Pneumoconiosis” means fibrosis of the lungs due to silica dust, asbestos dust, or other dust and includes the condition of the lungs known as dust‑reticulation;”
The particular problem in this case relates to the latter part of the definition:
“... and includes the condition of the lungs known as dust‑reticulation.”
4.	The case came before the medical appeal tribunal on a reference back made by a Commissioner following the setting aside by him of the decision of a previous medical appeal tribunal of 9 September 1993. The Commissioner’s decision was dated 13 October 1994 and was given on file CSI/34/1994. A copy of that decision is in the appeal papers at pages 59 to 61. The Commissioner’s decision dealt with an error arising over the use of the expression “a certifiable degree of pneumoconiosis”. When the claimant’s case was brought back before medical appeal tribunals on 21 March 1995 and 24 November 1995 the proceedings were adjourned to enable the pathologist who had conducted the autopsy on the deceased to supplement and clarify her report and to allow the claimant’s representative an opportunity to secure an independent pathologist’s report. Thus it came about that the evidence before the medical appeal tribunal on 16 August 1996 included a copy of the autopsy report (pages 8 and 9 of the appeal papers), two subsequent letters from the pathologist concerned (pages 75 and 79 of the appeal papers), a report by another consultant pathologist (page 82) and two subsequent additional letters from that pathologist together with some unidentified medical information on pneumoconiosis (pages 87 to 91 of the appeal papers).
5.	The medical appeal tribunal decided the diagnosis question adversely to the claimant and held that at no time since 5 July 1948 had the deceased suffered from prescribed disease number D1 or a sequela of that disease. In the reasons for their decision the tribunal referred to and quoted various portions of the medical evidence before them. They noted that both pathologists agreed that coal nodules were present in the deceased’s lungs and also agreed that the presence of dust foci in the lungs met the pathological definition of simple coalworkers pneumoconiosis. The tribunal went on to quote the statutory definition of prescribed disease D1 and found that the evidence did not enable the tribunal to diagnose prescribed disease D1. Their reasons concluded with the following passage:
“The chief issue in the case appears to us to be whether the definition of simple pneumoconiosis used by the pathologists satisfies the statutory definition. As the statutory definition explicitly refers to the presence of fibrosis and as neither pathologist has identified fibrosis in the coal nodules in [the claimant’s] lungs, their conclusion that simple pneumoconiosis is present conflicts with the statutory definition of the prescribed disease. Having now considered all the evidence including the pathological evidence, in our view PD D1 cannot be diagnosed because of the absence of fibrosis which is necessary to satisfy the statutory definition.”
6.	On a consideration of the reasons for the tribunal’s decision in the light of the terms of the statutory definition of pneumoconiosis I decided to direct a hearing of this appeal with particular reference to the question whether the statutory definition predicated the necessity for the presence of fibrosis of the lungs. I made reference to the possible relevance of reports of the Industrial Injuries Advisory Board, in 1953 (CMD 8866) and 1973 (CMND 5443) and leaflet NI226.
7.	Mr. Liddell helpfully took the hearing through the history of the statutory definition of pneumoconiosis from 1943 onwards. Although it had been considered unsatisfactory by the Industrial Injuries Advisory Council who had proposed its replacement in 1973 the definition was never amended. (There is one curiosity in that the terms of the definition were subtly re‑worded in Schedule 20 to the Social Security Act 1975 by placing a full stop after the words “other dust” and substituting “The expression” for the word “and” immediately thereafter. In the present definition contained in section 122 of the Social Security Contributions and Benefits Act 1992 the form of wording has reverted to the original form.) Mr. Liddell submitted that the effect of the definition was that dust‑reticulation would have to give rise to fibrosis of the lungs or be associated with or be a form of fibrosis. Dust‑reticulation could not be regarded as a separate and distinct condition from fibrosis if the definition as a whole was to make sense. He submitted that in medical terms there had to be a physical reaction and change in the lungs resulting from the deposition of the dust and not merely free dust deposits.
8. 	Turning to the decision of the medical appeal tribunal Mr. Liddell submitted that the tribunal had considered all of the relevant evidence and had quoted the statutory definition of the disease and had specifically rejected a diagnosis of prescribed disease D1. There was, he said no actual evidence of dust‑reticulation as to which the onus was on the claimant if this was claimed to have existed and the omission of the tribunal expressly to eliminate the possibility of dust‑reticulation should not be regarded as rendering the tribunal’s reasoning defective and their decision erroneous in law.
9.	Mr. Coulter on behalf of the claimant resiled from a concession that he had made at an earlier medical appeal tribunal hearing to the effect that the presence of fibrosis was essential to a diagnosis of prescribed disease Dl. He sought to rely on a medical appeal tribunal decision in another case which he had produced and which appears at page 124 of the appeal papers in which a pathology report showing a number of small coal nodules in the lung parenchyma had been held to confirm the presence of pneumoconiosis notwithstanding the absence of pulmonary scars or fibrosis. He contended that the presence of coal nodules in the deceased’s lungs demonstrated that coal dust had brought about a permanent change in the lungs of a kind claimed to be necessary by Mr. Liddell for any valid diagnosis of prescribed disease D1. Mr. Coulter pointed out that the question of possible dust‑reticulation had been raised by the medical appeal tribunal who adjourned the claimant’s appeal on 24 November 1995. That possibility had not been properly addressed in evidence or by the tribunal in the decision under appeal and accordingly that decision should not stand.
10. 	The first matter for my consideration is the statutory definition of pneumoconiosis in section 122 of the Contributions and Benefits Act 1992. Leaving aside for the moment any consideration of the particular medical terms found in the definition it is immediately apparent that the use of a definition in the form that the relevant expression means A and includes B raises a sharp question regarding the intended effect of the inclusion of B. Deeming and treating provisions are of course familiar in social security legislation where it is desired to extend one situation or category to another for some particular purpose. That is clearly not the form of the definition in this case. I agree with Mr. Liddell that to describe a condition in a definition and then to add that it includes a condition expressed in different words cannot sensibly imply that what is thus included is in some different category of condition. In my judgment the words “and includes the condition of the lungs known as dust‑reticulation” is part of the definition of the relevant expression “pneumoconiosis” and must be regarded as significant in the construction of the intended scope of the definition. Thus in that context I consider that these words must carry the implication that dust‑reticulation is to be regarded as a form of fibrosis of the lungs coming within the definition of prescribed disease D1, whether or not it would otherwise always be medically described as constituting fibrosis of the lungs.
11. 	That conclusion appears to be reinforced by reference to the reports of the Industrial Injuries Advisory Council already referred to. The prescription by Parliament of industrial disease for which benefit may be payable is in a broad sense a remedial measure and I am entitled to have regard to these reports in seeking to construe the scope of this statutory definition. See Black‑Clawson v. Papierwerke [1975] AC 591. It is apparent from the report of the Industrial Injuries Advisory Council on pneumoconiosis in 1953 (CMD 8866) that the Council regarded dust‑reticulation as a form of fibrosis and thus of pneumoconiosis and further that it ought accurately only to be applied when shown to be a pathological condition and not merely a radiographic appearance of the lungs. Paragraph 20 of that report is in the following terms:
“The present definition of pneumoconiosis derives from the Medical Research Council Report mentioned in paragraph 7, and is based on the presence of fibrosis, that is the laying down of fibrous tissue, in the lungs. The second half of the definition makes it clear that “the condition of the lungs known as dust‑reticulation” is to be regarded as a form of fibrosis, and so of pneumoconiosis. The term reticulation”, indicating a network, was originally applied to describe the pattern seen on the radiographs of a large number of South Wales coalminers during the investigation which was the subject of the Medical Resource Council Report. It was however also adopted in the phrase “dust‑reticulation”, to refer to what is described in the Report (Vol. 1, page 215) as “a widespread elaboration of reticular tissue throughout the lung, in response to the presence of excessive quantities of inhaled dust”. A distinction should therefore be made between “X‑ray reticulation”, which describes a radiographic appearance, and “dust‑reticulation”, which denotes a pathological condition of the lungs.”
12. 	The actual nature of the pathological condition of the lungs covered by the term dust‑reticulation is not unfortunately the subject of further discussion in either Council report. Medical diagnosis in accordance with the statutory definition is made more complicated by the medical tendency to distinguish between “simple” pneumoconiosis and “complicated” pneumoconiosis or “progressive massive fibrosis”. Under the heading “coalworker’s pneumoconiosis, D1, aetiology and pathology” in paragraph 69 of leaflet NI 226 the development of simple pneumoconiosis from aggregations of dust or macules is described in the following terms:
“Collagen fibrosis develops in these macules and forms scattered discrete fibrotic lesions constituting simple pneumoconiosis.”
Such a development would appear to represent the sort of pathological change described as necessary for any favourable diagnosis of prescribed disease D1 but whether such a pathological condition was present in the present case and whether that amounted to dust‑reticulation are not of course matters for me to decide. Before leaving the question of the statutory definition of pneumoconiosis I would only state that in my judgment the retention of the additional words relating to dust‑reticulation must be regarded as having been deliberately decided upon despite the views of the Industrial Injuries Advisory Council in 1973 and the retention of those words accordingly cannot be ignored.
13. 	There were undoubtedly passages in the evidence before the tribunal in this case which in my judgment necessitated the consideration of the possibility that the deceased’s lungs exhibited the condition known as dust‑reticulation. Thus for instance the consultant pathologist who undertook the autopsy described the lungs as showing “generally” “a fine nodularity and on section this appears to be due to a combination of small dust foci and thick walled, small bronchi.” Subsequently the pathologist confirmed that statement and said, at page 75:
“In answer to your question about fibrosis of the lungs, there is no gross or histological evidence of fibrosis. In my opinion there are sufficient dust foci to confirm the original statement of simple pneumoconiosis.”
The same consultant, at page 79, subsequently stated:
“The pathological definition of simple pneumoconiosis embraces a spectrum of appearance which includes coaldust foci (macules or nodules) of varying sizes with car or without reticulin and/or collagen formation (fibrosis). My statement about no evidence of fibrosis refers to the fact that in my opinion, there is no evidence of functionally significant fibrosis of the so‑called “progressive massive fibrosis” type as described in complicated pneumoconiosis.” [my emphasis]
The independent pathologist also used the term “functionally significant fibrosis”.
14. 	The medical appeal tribunal’s approach to diagnosis in the present case has already been described. A decision on the presence or otherwise of dust‑reticulation was of course a medical matter for the tribunal and it may be that their intention was to negate this possibility. However I have come to the conclusion that the medical appeal tribunal’s decision cannot be regarded as having adequately dealt in the reasons with the possible presence of dust‑reticulation. The confusion arising from the pathologists’ references to “functionally significant fibrosis”, which was not the test for the medical appeal tribunal, in my judgment made it essential for the tribunal to make it clear if in their medical judgment the claimant’s lungs did not exhibit a condition capable of being diagnosed as “dust‑reticulation”. In the absence of an express exclusion of the latter possibility which had been so specifically raised in the adjourned proceedings I have decided that the tribunal cannot be regarded as having adequately shown that their adverse decision excluded the possibility of the presence in the deceased’s lungs of a condition within the statutory definition of pneumoconiosis. That was a legal requirement of their decision for the purposes of regulation 38(4) of the Social Security (Adjudication) Regulations 1995.
15. 	It follows that with some regret having regard to the prolonged history of this case and the narrowness of the issue I must set aside the decision of the tribunal as erroneous in law and refer the case to another tribunal for reconsideration. The particular issue which must be addressed by the new tribunal is I think clearly focused in the preceding paragraphs of this decision. They will of course also have regard to the previous decision of the Commissioner on file CSI/34/1994.
16.	The appeal of the claimant is allowed.

Date: 24 November 1997	(signed) Mr. J. G. Mitchell QC
	Commissioner