IARC Scientist Unequivocal over Support for Complete Asbestos Ban
The clearest calls for a complete global ban on the trade and use of asbestos were voiced earlier this month during the unveiling of the International Agency for Research on Cancer (IARC) World Cancer Report 2014.1
Asbestos is a discrete carcinogen; it is causing attributable, deadly and, in most cases, untreatable disease so, yes, it should be banned, said Dr Bernard Stewart, co-editor of the IARC's 630-page, five-year update on the state of cancer science, during the Q&A that followed its presentation to the media in London on February 3rd.
It should be noted that, officially, neither the IARC as the cancer research arm of the World Health Organization nor its World Cancer Report are prescriptive, and that Dr Stewart emphasized that he was commenting from a personal perspective. However, he added that although the report doesn't state what anyone should do, it does so by pure implication.
And the message is clear: Increasing calls for a total ban on asbestos production and use contrast with continuing mining and widespread use of products containing chrysotile asbestos (an IARC Group 1 carcinogen), particularly in developing countries, according to a commentary2 on international efforts to tackle occupational carcinogenic exposures generally.
Noting the mixed success in reducing important exposures, such as asbestos a major contributor to the total occupational cancer burden, Dr Lesley Rushton, of Imperial College London, sees the reduction of high exposure levels as an urgent priority in low- and middle-income countries, where the newest technology may be unavailable, there is little or no regulation, and many may be employed in small workplaces, including children.
But as for low-level exposures too, the large number of workers who will contribute to the total occupational cancer burden must not be forgotten, Dr Rushton urges. Female workers are particularly affected; many are employed in service industries where low levels of many carcinogens, including asbestos, occur.
In calling for appropriate adaptation of effective regulation and control measures to different circumstances, Dr Rushton concludes: A concerted international effort is required to prioritise strategies to reduce occupational cancer in all workplaces where exposure to known carcinogens is still occurring.
The new IARC report also emphasizes that: the designation of an agent as carcinogenic is an important public health statement, as well as a scientific one.3 Referring to a list4 of agents associated with definite occupational carcinogenic exposure, asbestos in all its forms is described as being among the carcinogens that may induce the largest excess numbers of cases. Larynx, lung, mesothelioma and ovary are listed as asbestos-related cancer sites.
As for the responsibility that IARC has in addressing these issues, director and report joint-editor Dr Christopher Wild notes in his preface: IARC will play its part as it works for cancer prevention and control, with a particular commitment to low- and middle-income countries. This is, in itself, a poignant statement, given that such countries account for the bulk of the world's asbestos trade and use, under-regulation and safety concerns.
On the question (directed at the IARC panel during the Q&A that followed the report's launch)5 of whether the five-year update in cancer-related knowledge has changed the agency's views on the need to tighten asbestos trade legislation or safety regulation, Dr Stewart (University of New South Wales) responded on behalf of the panel, citing Australia's experience and current situation to explain his position:
We, like many countries, can predict accurately that the peak of mesothelioma deaths will occur between 2020 and 2025, despite the fact that we abolished virtually all industrial use of asbestos from around 1985 through to 1990. We face the daunting prospect that, although occupational exposure to asbestos resulting from mining it, milling it, demolition work, shipbuilding etc has gone, we are suddenly appreciating a new wave of non-occupational exposure, in home settings, for example, simply because people are unaware.
Although that exposure will hopefully almost certainly never reach the levels of attributable disease that occupational exposure has, the proportion of disease attributable to non-occupational exposure will still probably rise for a while, even as mesothelioma deaths decline in Australia, at least, Dr Stewart predicted.
The epidemiology of non-occupational exposure is now being documented in Australia, and to this extent, Australia reflects what is likely to happen in the US, UK and other similar-income countries, he explained, while noting that this does not necessarily apply to low- and middle-income countries (on the basis that they do not have a similar history of occupational exposure controls).
To conclude, when asked to clarify whether an outright global ban on the trade and use of asbestos should be advocated, Dr Stewart responded: I do not speak for the agency, but my personal position is yes. Building on the significant progress to date in terms of tackling conquering industrial exposure, he added: Hopefully we could have an absolute ban on the material.
With IARC advocating6 an ever-stronger renewed focus on prevention and early detection of cancer, as opposed to the traditional focus on treatment, Dr Stewart's comments carry added poignancy. In any case, whatever influence Dr Stewart's personal perspective can be expected to have on international asbestos-related policy-making, the weight of pure implication of the World Cancer Report 2014 itself is clear too.
February 19, 2014
1 International Agency for Research on Cancer, World Cancer Report 2014, February 2014.
http://www.iarc.fr/en/publications/books/wcr/wcr-order.php (for purchase from WHO Press)
2 Preventing occupational cancer: successes and failures (Dr L Rushton, Imperial College London), p141.
3 IARC, ibid, p142.
4 IARC, ibid, p138 (table 2.7.1).
5 Bernard Murphy, press conference, London, February 3rd, 2014.
6 IARC, press release, February 3rd, 2014.