Forecasting Principles: Analogies to the alarm over dangerous manmade global warming

Analogy description TitleAsbestos and Lung Disease Date: started in 1939


Forecast of impending disaster:

·       Alarm began in the 1960’s when a much higher than normal mortality rate was discovered in US shipyard workers of the 1940’s, who had prolonged exposure to high concentrations of asbestos, and that manufacturers were suppressing this damage to workers. Thus, an avalanche of compensation claims commenced in the USA, along with alarming forecasts. 

·       Widespread national alarm increased because of the misunderstanding about “asbestos” which commonly described several types of fibrous minerals, including amphiboles (blue and brown asbestos) used in shipbuilding as a fire retardant, and chrysotile (white asbestos cement) commonly used in buildings as a fire retardant.   So potentially millions of people could be exposed to a deadly hazardous material.  â€˜In 1982, Selikoff estimated 27 million Americans are “exposed to asbestos” ‘(source: )

·       Asbestos- related cancer cases in western Europe were predicted to soar over the next 35 years, causing half a million deaths, with half from mesothelioma (Peto, ’99, London School of Hygiene & Tropical Medicine) (source: )

·       INSERT: - Actual disease & death numbers / ratios… (this is difficult to find!)


Forecasting Method: (methods used to forecast the catastrophe

Method 1 - Extrapolation to a near-zero dose of a genuine effect from a large dose

·       From the tragedy caused by prolonged and high level exposure to ‘asbestos’, speculation about low level or uncertain levels of exposure through inhalation of asbestos fibres leading to lung disease (i.e. “one fibre can kill”, source: ) caused alarming forecasts of likely trends of diagnosis of millions with disease, such as asbestosis, lung cancer, and mesothelioma.   This speculation spiralled the likely trend for compensation, particularly in USA.

·         “even the slightest contact with its ‘deadly fibres’ can cause cancer” (Booker & North, Telegraph UK, 6/11/07)


Method 2 - Extrapolating that a hypothesized weak effect might become important over time or for a large population.

·       Given the mortality rate and disease of workers and miners exposed to amphiboles (blue and brown asbestos), provided the basis for this hazard to be projected onto other fibrous minerals commonly known as ‘asbestos’ (including white asbestos or chrysotile), which was extensively used in millions of buildings in the form of white asbestos cement (made up of 12% chrysotile and 88% cement). 

·       Predictions of numbers of deaths and disease and compensation claims deemed likely due to the risk of ongoing exposure by millions of people to white asbestos, even though the differentiation of the dangers of each type of ‘asbestos’ mineral weren’t clear. â€œone type of asbestos was as dangerous as another” source: ).   Scientific studies found that chrysotile, white asbestos, in its manufactured form poses no measurable risk to health (source: ). And this result has been challenged and is an ongoing debate for 40 years.


Actions called for: (actions by government or by others)

·         Governments, initially in USA and Europe, then followed into other countries, were asked to

·       Ban the use of asbestos, the production of asbestos, and that substitute products are to be used.

·       Regulate and require the removal of asbestos from millions of buildings to stop ongoing human exposure to it, and prevent predicted human catastrophic numbers of asbestos related illness.

·       Introduce legislation, and regulations relating to asbestos, including licensing of companies and workers in the testing and removal of asbestos

·       As of today, at least 46 countries have banned all forms of asbestos, while consumption increased in some other countries (World Bank Group, 2009)."

·         Legal compensation be paid to plaintiffs and through class actions by companies

·         Research into asbestos related production and effects of exposure

·         The EU ban of asbestos by a political powerful lobby group ‘Ban Asbestos’ in 1991, supported by law firms, asbestos contractors, and multi-national manufacturers of asbestos substitutes, trade unions, ‘progressive politicians’, ‘concerned scientists’, environmental pressure groups eg. Greenpeace, and ‘asbestos victim support groups’.


Endorsements of the forecast:

Effects of asbestos were endorsed by various scientists, politicians, and reports of the dangers of asbestos were widely covered by the mass media, which egged on the alarmism. Leading scientists from institutions (such as …. University), politicians (such as ……); media - Reports of the dangers were widely covered by the mass media, which egged on the alarmism.

·       Legal compensations endorsed asbestos to be damaging to human health, e.g.Lawsuit ‘Borel case’ 1973 awarded compensation to victims exposed to asbestos, further increasing claim numbers, soaring in the USA by the end of 1980’s.

·       Scientists studies by Dement, 1994, and Smith and Wright, 1996, supported lobbyists’ campaign by showing that chrysotile to be more dangerous than supposed, as the main contributor to pleural mesothelioma, demonstrating the harmful effects from asbestos exposure on people

·       EU directive, 1999/77, ruled that ‘no threshold level of exposure has yet been identified below which chrysotile asbestos does not pose carcinogenic risks’. It imposed a ban on the importing, manufacture or sale of any products containing white asbestos, to be made absolute by 2005 throughout the EU. Law interpreted that “just one fibre was enough to kill”

·       The UK’s Health Department (HSE), in 2002, introduced new regulations, EU law compliant, banning chrysotile, contradicting their own findings.


Challenges to the forecast – counter findings that asbestos not as dangerous as thought

·       Independent scientific experts found white ‘asbestos’, or chrysotile, not to be as dangerous as blue and brown asbestos, or amphiboles, and that the danger chrysotile poses to human health to be insignificant. The white asbestos cement which made up more than 90% of asbestos in all buildings in USA was found to have non-existent “fibre release”, therefore not damaging to the lungs.

·       US federal courts, 1991, reversed the ban on white asbestos, stating that on EPA’s own data, “it was likely to cause many fewer deaths than ‘the ingestion of toothpicks’. (Source:     )”

·       Scientific study, in UK, 1996, found that the ‘degree of hazard’ depended on type of fibre (greater with amphiboles than with chrysotile) and the size and length of the fibres (long fibres more hazardous than short); and that ‘the balance of toxicological evidence does not support the “no-threshold” model for asbestos-induced lung cancer. This indicated that there was a threshold level of exposure below which asbestos was not dangerous.

·       Harvard University study, 1998, compared the official projection of 1 in 100,000 faced lifetime risk of dying from exposure to Asbestos in buildings, with other types of death and found the chances of dying, for example, in an air crash to be 730 times higher.

·       Leading British statisticians, John Hodgson and Andrew Darnton published a paper in 2000, based on comprehensive review of all major studies (70) over past 20 years that included exposure levels, on highly exposed groups such as insulation workers, textile workers and miners.

·     Results showed that for the vast majority of population the risks faced by low level of exposure & the risk of contracting mesothelioma from contact with asbestos cement was so low, as to be ‘probably insignificant’. And the risk of lung cancer was argued that this was ‘zero’.


Outcomes of the conflict: (over the alarming forecast and calls for action, including forecast accuracy)

·       The forecast accuracy has been wrong in degree (minor effects actually occurred) for ‘white’ asbestos (chrysotile) which was predicted to cause the same increase in illness and mortality as ‘brown and blue’ asbestos (amphiboles). 

·       Government programs remain in place, and costly policies continue to be implemented, after predicted levels of illness and death have not occurred

·       Alarm and debate has continued by advocates of family members with asbestos related disease (ARD), lobby groups, scientists reports, even though predicted levels of illness and death have not occurred because there is ongoing debate about the purity of the chrysotile fibre when mined as it is often found with amphibole fibre, and therefore its existence in buildings etc. may not be without harmful effects. Also developing countries are continuing to use chrysotile asbestos even though many western countries have banned it, and working conditions are not necessarily regulated to the level of western countries, so scientific study continues on the different type of fibres, and which analytical methods should be used to make accurate identification, and for studies of workers exposed to the fibres.


List References

Booker C, & North R, 2007, Scared to Death, Continuum UK, London

Booker C, & North, Telegraph UK, 6 Nov 2007

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