The Industrial Injuries Advisory Council (IIAC) has published a position paper on coal mining, silicosis and lung cancer[i]. The paper concerns the potential eligibility of coalminers with silicosis to claim benefit for lung cancer under the prescribed disease, D11, ‘Primary carcinoma of the lung where there is accompanying silicosis’.
Silicosis, lung cancer and lung cancer with accompanying silicosis appear on the list of diseases prescribed for Industrial Injuries Disablement Benefit (IIDB) as three separate entries. Like other entries on the list, to receive benefit, the claimant’s occupational history must meet certain criteria. In order for a disease-occupation pairing to appear on the list, the risk of developing the disease must be doubled in people with the particular occupational exposure.
Silica is classified by the International Agency for Research on Cancer (IARC) as a human carcinogen. Silica can also cause silicosis, which is one of a group of occupational lung diseases known as pneumoconiosis. These are onset by inhalation of various types of dust.
An earlier IIAC review found that, in those who have had enough silica exposure to develop silicosis, the risk of lung cancer is more than doubled. The entry on the list of prescribed diseases for lung cancer with accompanying silicosis lists 9 occupational situations in which silicosis may occur, one of which is ‘tunneling in, or quarrying sandstone and granite’.
However, work as a coal miner is not explicitly mentioned. Last year, a trade unionist representative posed the question of whether this description could apply to coal miners, and if not, whether the terms should be extended.
Silicosis is a different disease from the form of pneumoconiosis most commonly found in coal miners, also known as coal worker’s pneumoconiosis (CWP). Although silicosis and CWP both fall under the umbrella of pneumoconiosis and show similar pathology, the two diseases take different courses; CWP is much less aggressive than silicosis.
Silicosis was recognized in the Workman’s Compensation (Silicosis) Act of 1918 and then with other pneumoconiosis types, in the Workmen’s Compensation Act (Silicosis and Asbestosis) 1930. Coal miners were included in the 1930 Act, because it was shown that they could develop silicosis from cutting or drilling sandstone. CWP was initially thought to not be serious, but it was understood that those with CWP were at increased risk of potentially fatal Progressive Massive Fibrosis. In 1943, the Workmen’s Compensation Act was extended to include any type of pneumoconiosis, including that of coal miners. Since then, coal miners have been able to claim compensation for pneumoconiosis, whether it is silicosis or CWP.
The current prescription for pneumoconiosis within the IIDB scheme (PD D1) includes coverage of coal workers under the following terms:
‘1) (a) The mining, quarrying or working of silica rock or the working of dried quartzose sand or any dry deposit or dry residue of silica or any dry admixture containing such materials (including any occupation in which any of the aforesaid operations are carried out incidentally to the mining or quarrying of other minerals or to the manufacture of articles containing crushed or ground silica rock);
(b) the handling of any of the materials specified in the foregoing subparagraph in or incidental to any of the operations mentioned therein, or substantial exposure to the dust arising from such operations. ….
(10)(a) Work underground in any mine in which one of the objects of the mining operations is the getting of any mineral;
(b) the working or handling above ground at any coal or tin mine of any minerals extracted therefrom, or any operation incidental thereto;
(c) the trimming of coal in any ship, barge, or lighter, or in any dock or harbour or at any wharf or quay;…’
Confusingly, in prescribed disease category, D1, the different types of pneumoconiosis are not differentiated, i.e. both silicosis and CWP are included.
Can coal miners also claim for lung cancer if they have silicosis, under prescribed disease category, D11?
The Council expects that a coalminer with silicosis and lung cancer should be able to apply for benefit for lung cancer, because it is accepted that exposure to silica dust and silicosis can arise during coal mining work.
However, bringing a claim may be complicated, for several reasons.
Coalminers are not generally considered to be at increased risk of lung cancer, because there is no evidence for an exposure-response relationship with coal dust exposure and lung cancer. The risk of lung cancer only increases when there is substantial exposure to silica. As discussed above, most pneumoconiosis in coalminers is CWP, rather than silicosis. What is more, is not always possible to differentiate silicosis from CWP by medical imaging; knowledge of occupational history and silica exposure may be required, and this may be difficult to obtain and verify.
To claim for D1 and D11 benefit, the claimant will always have to show evidence of exposure to silica, regardless of whether they are a coal miner. A judgement will have to be made on whether the dust exposure was plausible and whether the dust contained a great enough quantity of silica to cause the alleged health effects.
Tasks in coal mines that involve exposure to silica, include tunneling, hard heading and brushing, roof bolting, drilling (other than into coal), but explicitly involve cutting hard rock, usually sandstone.
The Council recommends that a prima facie case exists for recognising a disease in a coalminer with lung cancer if:
- A diagnosis of silicosis can be sustained; and
- Their work involved tunneling in, or quarrying sandstone or granite.
Equivalently, a coal miner who meets the requirements for pneumoconiosis caused by silica in category D1 would also satisfy the exposure requirements for D11.
The Council recommends that this guidance be promulgated to medical assessors and decision-makers. It is not necessary, at this point, to change the wording of prescribed disease D11.
[i] Coal mining, silicosis and lung cancer. Industrial Injuries Advisory Council Position Paper 41. June 2018 https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/717040/coal-mining-silicosis-and-lung-cancer-iiac-position-paper-41.pdf (Accessed 29 June 2018)