Christopher Booker is closer to agreeing with the Health and Safety Executive (HSE) about asbestos than your readers - or he - might realise.
But let me be clear, his claim that HSE has blurred the distinction in the hazards posed by the different asbestos types is simply not true. Neither do we recognise the gloss he places on the conclusions of our scientists.
We agree that the risks to human health for white asbestos are substantially lower than for brown or blue asbestos. We also agree that the level of risk in relation to any carcinogen depends on the degree of exposure. However, we strongly disagree about the implications of the scientific evidence for how asbestos cement products should be dealt with.
This evidence does indeed show that brown and blue asbestos are particularly hazardous. However, it also shows that exposure to white asbestos leads to a risk of lung cancer. Yes, there is uncertainty about a level of exposure - a threshold - below which that particular disease is unlikely to be caused. There is also uncertainty about the actual scale of the risk at different levels of exposure to white asbestos in relation to the other major asbestos related cancer, mesothelioma. Risks were found to be considerably higher in some research studies than others, and the extent to which contamination of white asbestos by other forms may have played a part is not always clear cut.
Putting it simply, white asbestos is implicated as a cause of both lung cancer and mesothelioma though uncertainty remains about the precise nature of how the risk changes at different levels of exposure. It cannot be called safe by any sensible person.
Based on the evidence, the regulatory system in Britain distinguishes between different types of asbestos-containing materials according to how hazardous they are likely to be. This is why we have a licensing scheme and require a very high level of control for products most likely to contain blue and brown asbestos - and why work with asbestos cement does not usually fall within our licensing scheme.
Even so, the evidence still justifies precautionary controls being imposed on work with products that contain white asbestos alone - we cannot rule out the link to cancer. It is further justified by the fact that in reality it is impossible to be completely sure that asbestos products really do contain white asbestos alone. Materials like asbestos cement can and do contain other forms of asbestos, but rarely in a way that those working with it are able to distinguish. And when asbestos cement is broken, research shows that asbestos fibres are released.
If we were to accept less rigorous controls of work with asbestos cement, there is no doubt that the result would be higher exposures to white asbestos as well as more individuals being exposed to more dangerous forms of asbestos.
The regulatory system for asbestos in Britain is therefore both a proportionate and responsible approach to dealing with what remains Britain's biggest industrial killer.
Health and Safety Executive