Posted By Adrian Watson Dear Geoff, They will, because they will. Their agenda is not based on science, but politics. Regards Adrian Watson

Posted By Laurie Of course white asbestos isn't hazardous, just as Thalidomide wasn't Laurie

Posted By Geoff Burt Laurie I used the word 'evidence' and was hoping to get considered responses. We're talking about asbestos - I'm not sure what thalidomide has to do with it? The problem is that asbestos is a very emotive subject. That doesn't mean we can't stand back and look at the evidence - and then debate it on its merits. Geoff

Posted By Richard Bennion The majority of Chrysotile (white) asbestos products used within non domestic buildings, domestic buildings, plant, equipment and vehicles require as little management, as knowing where it is, ensuring a label is attached (if possible)and informing any persons who may come into contact with it (layman's terms). Cement, Pipe Gaskets, paper linings, rope packing, fire blankets, vinyl floor tiles, artex, putty etc etc.(the list is endless) pose a low asbestos risk if in good condition, they are usually bound in a matrix, encapsulated behind another material, enclosed between another material or in an external environment, and so the requirement to remove is fairly unlikely and any minor maintenance work (see CD 181) can be done in a controlled manner by competent persons (see HSE guidance Asbestos Essentials - Task Manual). The main issue with the implementation of the consolidating and amending "control of asbestos at work regulations 2002"?. Is to ensure that asbestos containing materials (ACMs)are identified and that persons working near or on the materials know that they contain asbestos. A massive amount of organisations still don't check for the presence of ACMs in their buildings prior to small tasks such as Fire detection installations, IT work, pest prevention work, tile replacement, pipe work replacement, etc etc. The main issue is that the majority of the ACMs contain Amphibole asbestos forms such as Amosite (Brown)and Crocidolite (Blue) asbestos with usually trace quantities of Chrysotile. (Amphibole asbestos has been proven to cause lethal health effects) So the new legislation is a wake up call for property owners, maintenance managers, estates officers, fire officers, OSH practitioners to start acknowledging the importance of identifying as far as reasonably practicable a (cat. 1) carcinogenic fibre (Crocidolite, Amosite, Chrysotile, Fibrous Tremolite, Fibrous Actinolite, Fibrous Anthophyllite) that resides in their properties and kills more of the population than road traffic accidents per annum (recent TUC reports). If we start to distinguish between asbestos containing materials than surely standards of good practice and safe systems will drop, and complacency may creep in both with in-house employees, contractors and competent asbestos removal contractors in an area where standards are questionable already. But thats just my opinion. Richard

Posted By Adrian Watson Laurie, As an aside Thalidomide isn't that toxic; and unless you happen to be female and in the first trimester of pregnancythere was no serious risk from using it. In fact I recall that Thalidomide is now being used to treat leprosy. Regards Adrian Watson

Posted By Geoff Burt Tony = you wrote: 'Finally, these proposed regulations will, if adhered to, prevent future generations dying from asbestos related diseases, especially construction workers who make up 30% of those dying from such diseases. We can do nothing about the legacy of past failure and criminal complacency, but we can do something for all those workers who are currently disturbing asbestos and putting their lives at risk'. Forgive me Tony - but do we not already have regulations in place that meet this requirement? The point I feel is missed is that the numbers you quote apply to people who suffered gross exposure in the 50s to 70s - surely those levels of exposure are now a thing of the past. What are the forecast fatality figures for 2030 to 2040 from present day exposure levels - that might give us a better idea of the dangers. Geoff

Posted By Robert K Lewis Tony I am intrigued by your reference to younger mesothelioma sufferers. The argued problem for this disease was the long latency period and you now seem to imply that it is becoming shorter. The questions posed are thus: Have there been incorrect assumptions in the past which may distort all our assumptions? Are there other causes of mesothelioma that are more likely to trigger the disease onset of which we are currently unaware due to the total focus on the amphiboles as the sole causative factor? Are there genetic or environmental changes occurring that have shortened the latency period? Bob

Posted By Robert K Lewis Robert Tony specifically referred to mesothelioma with regard to latency and this has generally been regarded if I remember as 15-30 years with a mean around the 20 year mark. I know of some 48 year olds in the early 90s who had contracted it in the 60s. My expectation would be that the age of the disease becoming visible would remain at around this age and later, except Tony talked of younger people. I am not confusing the stats. for mesothelioma with other asbestos diseases, at least I think not. Bob

Posted By Tony Whitston Geoff and Adrian, Yes. My paragraph Geoff cites re younger people is misleading. Peto's study is looking at mesothelioma patients under 60 'because the under-60s are the age group where possible exposures in the general construction trade appear to be most important'. The point I intended to make, but failed to do, is that construction workers, the second wave of mesothelioma victims if you like, are a significant section of total mesothelioma victims and this study will look at the evidence for this. The feared third wave are those, particularly construction workers, who are likely to disturb asbestos in situ. Now, Adrian is right one cannot presume a link and the study will not forecast possible deaths in 2020-2030. But, the changed nature of exposure, certainly for some of the younger mesothelioma sufferers I have seen suggests to me that the type of exposure associated with maintenance work on buildings or just friable asbestos poses a significant risk. But, that is certainly not a scientifc fact. Your' right to question the sense of my reference to younger people! As for the HSE's estimates of numbers of people dying annually from asbestos related diseases. Revitalising Health and Safety Consultation Document cites 3,000 as annual asbestos deaths. The HSE statistics for 2000/2001 makes precisely the point I referred to stating that there is at least a ratio of 1:1 for mesothelioma and lung cancer, asbestos related deaths, and a likely ratio of 2 lung cancers per 1 mesothelioma. The HSE quote the figure of 3,000 annual asbestos related deaths in several documents and also the ratio of lung cancer to mesotheliomas. Indeed, I was asked to check the above with the HSE some weeks back and I was referred to their several statements confirming this. Mesothelioma deaths have hovered around the 1,600 per year since 1998, so I presumed the figure quoted by Adrian was the latest for mesothelioma. The TUC say that 5,000 die per year. It is well known that the DWP and courts require evidence of asbestosis (or at least diffuse pleural thickening) as evidence that lung cancer is associated with asbestos dust. But this requirement is to counter the presumption that smoking caused the cancer. Many chest physicians dispute the necessity for the presence of asbestosis, eg Dr Rudd who is currently running mesothelioma trials at St Bartholemew's hospital. Like mesothelioma,lung cancer is not a cumulative disease (asbestosis is), but arises from a single 'event', causing a change to an individual cell. The Fairchild case rehearsed many of the arguments about this 'event'in the context of the 'single fibre' argument. The relationship between asbestosis and lung cancer is more a medico/legal construct than a scientific or medical fact.

Posted By Tony Whitston Rob, The typical age for those suffering from mesothelioma is more in the range of 60. The fact that younger people are presenting with this disease doesn't suggest a more aggressive variant, but is indicative of the dangers of new forms of exposure occupationally. This may in the long-term support the view that inadvertant exposures per asbestos in buildings is certainly risky... but this is speculation and shouldn't distract us from the substantive issue of whether chrysotile causes mesothelioma and whether the new regs are justified. Just to continue the question of lung cancer associated with asbestos exposure I have copied an extract from the HSE statistics 2000/2001 2.91 There is evidence to suggest that these figures substantially underestimate the true extent of the disease. In heavily exposed populations there have typically been at least as many, sometimes up to five times as many, excess lung cancers as there have been mesotheliomas. The ratio depends on a range of factors (the most important of which are type of asbestos, level of exposure, age at exposure and smoking), so one cannot be too precise about the overall ratio. A reasonable rule of thumb would be to allow for one or two extra lung cancers for each mesothelioma. Going forward in time the ratio is likely to fall, because the mesotheliomas will increasingly be generated by low exposure levels (meaning fewer lung cancers per mesothelioma) and because smoking levels have fallen since the 1960s. This discussion has been wide ranging and interesting, but it has done nothing to persuade me that the HSE is wrong to introduce new regulations to manage asbestos in buildings. Frankly, I find it disconcerting that so many practitioners accept the views of the asbestos industry on this question. Tony

Posted By Adrian Watson Please note that I spotted a couple of errors as soon as I submitted my response. My appologies, the corrected version is as follows: Dear All, There is no doubt that many workers in the construction industry were exposed to heavy exposures in the 1960’s and 1970’s. I have spoken to many carpenters and electricians who recall being present or cutting sheets of asbestos insulation board using circular saws into strips 150 mm (6 in wide) for up stands or into smaller sheets for fire breaks. I have also spoken to plumbers who recall mixing asbestos insulation in buckets and having asbestos fights with the insulation. What is often forgotten is that many of these workers would have done this work as apprentices and would have been exposed as 15 and 16 year olds as apprentices. These exposures would have been very high and would have resulted in these workers having a significant risk of suffering asbestos related disease later in life. From the available information the age profile appears to be getting older, i.e. there is a reduced risk for younger age groups. With respect to Tony’s sample of 10 persons it is too small to be meaningful. Furthermore the single fibre theory was discarded long ago as it was based upon a theory of carcinogenesis prevalent in the 1950’s. It is now accepted that there are many stages in the development of cancer and that normal homeostatic processes within body can cope with some of these stages. Thus whilst the likelihood of that event occurring increases with exposure levels, it is probable that there is a threshold for every individual within which the risk of disease is zero, but above which there risk increases. This would also explain to a moderate degree why high but brief episodes of exposure are more important than lower exposures over a longer period for the same substance. With different substances the half-life, toxicological, physical, chemical factors need be taken into account as well as the life style and patho-physiological processes within the individual. The problem I have with from the abstract from the HSE statistics 2000/2001 is that it does not reconcile with the available evidence, including that from the HSE itself. In their review of fibre toxicity (HSE 1996 EH 65/30) it states:- “There appears to be an association between pulmonary fibrosis and lung cancer in that both diseases show a similar dose-response relationships with respect to asbestos exposure, show similar doses, show similar latent periods for development, show a similar dependence on fibre type and size, and both diseases emanate from the same underlying chronic inflammatory conditions. These observations suggest that asbestos induced cancer, like fibrosis, is a threshold phenomenon. It can be concluded that exposures which are insufficient to elicit chronic inflammation/cell proliferation will not incur any increased risk of lung cancer.” It also states... “ The Doll and Peto (1985) risk assessment for chrysotile induced lung cancer was based on a linear no-threshold model applied to the mortality data from chrysotile textile manufacture. However the balance of toxicological evidence does not support the no-threshold model for asbestos induced lung cancer.” Finally, it states... “ Evidence from human studies suggests that amphibole asbestos may lead to the development mesothelioma at lower levels of cumulative exposure than would be required to cause lung cancer.” This evidence, does not reconcile with their view as stated in paragraph “2.91 There is evidence to suggest that these figures substantially underestimate the true extent of the disease. In heavily exposed populations there have typically been at least as many, sometimes up to five times as many, excess lung cancers as there have been mesotheliomas. The ratio depends on a range of factors (the most important of which are type of asbestos, level of exposure, age at exposure and smoking), so one cannot be too precise about the overall ratio. A reasonable rule of thumb would be to allow for one or two extra lung cancers for each mesothelioma. Going forward in time the ratio is likely to fall, because the mesotheliomas will increasingly be generated by low exposure levels (meaning fewer lung cancers per mesothelioma) and because smoking levels have fallen since the 1960s.” If you also take into account the recent estimates which suggest that a smoker who is exposed to asbestos is around 1.1-2.8 times at greater risk of lung cancer than if he smoked or was exposed to asbestos alone (Berry et al 1985), this would suggest that with 171 asbestosis deaths in 1999, the number of asbestos deaths attributable to smoking and asbestos related lung cancer is around about 200-400. This estimate is from about one quarter to one eighth of the number of recorded mesothelioma deaths, 1595 in 1999 and 10 times the number of asbestos related lung cancers, 42 (HSE 2001). Sword estimates the number of lung cancer deaths to be 81 in 1999 (HSE 2001). Whilst we all accept that there is some underreporting, I do not credit any scientific accuracy to my estimated figure of 200-400 lung cancer deaths, but I suggest that it has slightly more credibility than HSE’s estimates of 1700-3400 lung cancer deaths. Whilst I will forgive the implied suggestion that some of us uncritically accept the views of the asbestos industry because we do not accept unreservedly HSE’s views, it should not be forgotten that HSE is not a neutral observer. They have vested interests in the proposed regulations, including those of receiving increased resources from government and increased income streams from laboratories, through the rice and aims schemes, to receiving a greater political profile. It should also be noted that persons working within the consulting and laboratory sectors and UKAS as well as HSE man the HSE’s advisory working parties. Now whilst I do not doubt the personal integrity of those within the working parties, I also do not doubt that the HSC is not getting unbiased opinion through the HSE. For the record I do not work in the asbestos industry, but I am a consulting Health, Safety and Environmental Health Practitioner in the consulting sector. Many Regards Adrian Watson LLM MSc Dip Occ Hyg FBIOH ROH FIOSH RSP MCIEH

Posted By Tony Whitston Dear Adrian and Geoff, Adrian, it was Bob not myself who mentioned 10 mesothelioma sufferers, perhaps you corrected this in your second version. Your credentials are impressive, Adrian, as listed in your recent message, and you are certainly well qualified to pass informed comment. Of course there are similarly, or better, qualified non-partisan commentators who will disagree with you. There's the 'rub': we all have to consider the evidence ,contradictory as it may appear. There may be doubt based on intelligent comment cast on many assumptions made by the HSE and others who warn that chrysotile is a hazard. However, given the body of evidence supporting the view that chrysotile is a hazard I would personally expect that more practitioners would accept the 'precautionary' approach on this issue, which is precisely the one the HSE is taking. And this was my point, not that you or any of the other commentators belong to the asbestos industry, like our friend, John Bridle. I regret that you feel you have to protest your status: I never doubted it. Really Geoff, the proposed regs are not concerned with demolition and construction sites: there is legislation to cover these. The purpose of the new Regs is, as I have said before, to deal with the disturbance of asbestos, mostly inadvertently in buildings where no one has bothered to identify it or anticipate the possibility that it is there. And of course I don't expect everyone to agree with my preference for the HSE's view. But I think I am entitled, in passing, to comment on the fact that so few in this discussion do 'veer' to the precautionary approach. But it has been a very informed discussion, especially the contributions from Adrian which I have especially enjoyed. Tony

Posted By Robert K Lewis May I as a mere mortal SP trying to understand my industry ask some more questions about this without inviting a welter of facts. I recognise that my encounters with mesothelioma are limited, but it does seem to me that the messages are contradictory. Statements are made which implicitly refer to high exposures as if they were the norm in construction, particularly nowadays. I would also have to dispute some of the oral traditions which seem to have taken on a life of their own and which are recounted as though they are the speakers own story. I have had specific experience of this. In my student days I spent time lagging reaction vessels with blue asbestos rope. Some 15 years later I heard a fellow student describe this as being smothered in dust and having snowball fights with it. I don;t condone the situation in those days but wonder at some levels of raconteurial accuracy. The HSE are still forecasting increases in finite numbers of asbestos related deaths and yet argue that exposure levels are low and controlled. Are we past the peak, in absolute numbers, or not. If not what is different about current exposure today that accounts for this. Bob