Written evidence from Mesothelioma UK (ASB0037)
5th January 2022
Members of the Mesothelioma UK team watched with interest the House of Commons Work and Pensions Committee hearing on Wednesday 15th December 2021. We were pleased to contribute to the first evidence session following which we submitted supporting information. We thank you for allowing us to submit further evidence which we feel compelled to offer following this second hearing.
This additional evidence is in response to points made by Prof Julian Peto.
This was a central claim made by Professor Peto. Recently Prof Peto’s team have undertaken the TIPS study which looks at samples of lung material resected from live patients who have either had mesothelioma, lung cancer or pneumothorax.1,2 The last of these groups is interesting because they are younger and relatively healthy. Prof Peto wishes this research to continue and suggests that it will be possible to pursue groups of interest, such as teachers who have had surgery for pneumothorax. In addition, (at 10:17.30) he says it is one that can be performed by the HSE. Overall, however, the testing of lung tissue seems to provide useful data and we are sympathetic to Prof Peto’s view that this research should be funded to continue. In addition, we understand that the HSE is presenting evidence to the Work and Pensions Committee in February, where the possibility of their undertaking this work could be explored.
The second claim follows from the first but Prof Peto makes explicit criticism of three other attempts to estimate exposure. The first is the idea of large-scale air monitoring of the sort advocated by Airtight on Asbestos. He dismisses this with an argument that seems vague. It is that we need to know people’s 10-year exposure in an environment rather than the amount in the air at one particular time, even if that is several days of monitoring. He quotes no data to support this and doesn’t acknowledge the fact that this type of air monitoring is already established and routine in several European countries.
Secondly, Prof Peto dismisses the use of personal histories, where people go back through their occupational and other history to look for exposure to asbestos. He supports this argument with data from the TIPS. He uses an anecdote of a worker whose lungs were heavily contaminated with asbestos but who denied any exposure to it. This weakness with personal history is clearly a problem but it is not one that has stopped such histories being used to form a clinical picture and in legal cases to fight cases for negligent exposure to asbestos by those who subsequently develop mesothelioma. In addition, based on histories provided by relatives or the deceased prior to their death, coroners can and do declare mesothelioma to be an industrial injury even where they have no evidence of asbestos in the lungs and where the person has no history of working in a high-risk industry.
The third source of data is the ONS mortality statistics. Prof Peto acknowledges their usefulness but points out two weaknesses with them. The first is that there can be a 50-year latency between exposure to asbestos and likely death from it. The second is that the ONS only records your last occupation. Prof Peto suggests that this is a problem for some groups, he cited male teachers as an example. We believe the problem to be wider than this example suggests; many women work in deteriorating public buildings such as schools and hospitals but also have uneven occupational histories such that their last occupation is not that of, say, teacher or nurse.
Howie has suggested that a problem in estimating occupational risk is created by the fact that the ONS only records occupation where the individual dies before age 75..3,4 Prof Peto rejected this claim, suggesting that once we have the data up to that 75 years then we know the trajectory from that point onwards. Howie’s point, however, is that those in high-risk industries will have been heavily exposed and be likely to die before 75. Others, such as teachers and nurses, are less heavily exposed and be more likely to die after that age such that their occupation will not be recorded. It is for this reason that the age 75 cut off skews the data against those who work in hazardous environments rather than hazardous occupations.
Prof Peto was dismissive of the Airtight on Asbestos campaign and refers, we believe, to the campaign’s paper “Don’t Breathe In”. 4 which is one of the papers used by the campaign. He questioned why this paper does not refer to his TIPS research. We thought this might be because the papers we have read from the TIPS study do not refer to risk at school or in hospitals which is the focus of the Airtight on Asbestos campaign. Prof Peto questioned why the Airtight on Asbestos campaign makes use of Howie’s paper which Prof Peto stated to the committee had not been published in a sufficiently academic journal. We can only assume Howie, who may respond himself, was keen to publish his work in a journal suitable for the Occupational Health areas in which he works.
Professor Peto dismisses as nonsense the claim in Airtight on Asbestos paper that for every teacher that dies of mesothelioma, nine former pupils will die. Although this is stated in the paper, it is not the result of work done by the group. It is, instead, a claim from statistical modelling performed in a report by the US Environmental Protection Agency.5 As such, it can’t be summarily dismissed as academically inadequate. Indeed, given the lack of any other modelling of the question of how many pupils are at risk when teachers are at risk, it deserves close attention.
To support this point, Professor Peto refers to research from the 1980s which suggests that removal of asbestos increases the amount of asbestos in the air and therefore the risk to others. It is noteworthy here that Prof Peto is willing to use air monitoring for evidence (of what happens when asbestos is removed) even though he has dismissed it elsewhere. His suggestions are nonetheless plausible, although they are addressed in other documents and were discussed in the second half of the hearing on this day. In addition, the idea of leaving asbestos in situ has clear theoretical problems. One is how long this policy can be maintained as buildings deteriorate; and as we have noted elsewhere, schools and hospitals are subject to high rates of wear and tear. The second is that, whilst Prof Peto extrapolates a decline in the rates of mesothelioma over time, this must be subject to doubt if asbestos is left in situ in old public buildings. This policy cannot work long-term.
In passing, Prof Peto suggested in addition that removal of asbestos would be damaging to the public purse. Large scale public policy decisions cannot be made in this offhand way. In this regard, there are really two decisions to be made. The first is whether phased removal of asbestos from public buildings, starting with schools, would benefit public health. We believe a strong case can be made in favour of such a policy. The second is whether the benefit would justify the cost involved. This is a judgement that can only be made through health economic modelling. This is performed in a number of institutions including the School for Health and Related Research (ScHARR) at the University of Sheffield and the York Health Economics Consortium at the University of York.
In summary, we felt that whilst some of Professor Peto’s contribution might be supported in terms of the TIPS data, most of his points are unsupported by evidence or are theoretically questionable.
Thank you for considering this additional contribution from Mesothelioma UK that has been prepared for the charity by Peter Allmark, Senior Research Fellow at Mesothelioma UK’s Centre for Research based at the University of Sheffield.
Liz Darlison MBE Peter Allmark
CEO Senior Research Fellow
Mesothelioma UK Mesothelioma UK Centre for Research University of Sheffield.
1. Gilham C, Rake C, Hodgson J, et al. Past and current asbestos exposure and future mesothelioma risks in Britain: The Inhaled Particles Study (TIPS). Duncan A Edwards JG, Lim E, Milton R, Morgan I, O’Keefe P, Power D, Rajesh PB, Rathinam S, Rassl DM, Routledge T, Shackcloth M, De Soyza A DM, ed. Int J Epidemiol. 2018;47(6):1745- 1756. doi:https://dx.doi.org/10.1093/ije/dyx276
2. Gilham C, Rake C, Burdett G, et al. Pleural mesothelioma and lung cancer risks in relation to occupational history and asbestos lung burden. Occup Environ Med. 2016;73(5):290-299. doi:10.1136/oemed-2015-103074
3. Howie R. Mesothelioma Deaths in Teachers and Nurses in Great Britain. Environ Heal Scotl. 2017;29(4):35-37.
4. Morrin, M; Aldane, J, King, H. Don’t breathe in: bridging the asbestos safety gap. 2019. Airtight on Asbestos, Res Publica. https://www.airtightonasbestos.uk/
5. Environmental Protection Agency (USA). Support Document for Proposed Rule on Friable Asbestos-Containing Materials in Schools: Reoirt No. 560/12-80-003. Washington; 1980. books.google.co.uk.