The Asbestos Story: A tale of public health and politics
Public awareness of the hazards of asbestos can be dated back to the period immediately following the death of Nellie Kershaw aged 33, in 1924. Nellie had worked for 7 seven years in a textile factory spinning asbestos fibre into yarn and as a result, she died of severe fibrosis of the lungs.
The pathologist William Cooke found retained asbestos fibres in the lungs and so therefore, called the cause of death asbestosis. Nellie Kershaw was not the first case of lung fibrosis to be caused by asbestos to have been reported.
In 1899, Montague Murray had reported the case of a 33-year-old man who had worked for 14 years in an asbestos textile factory. He had died of lung fibrosis which Montague Murray, who had also found asbestos fibres in the lungs, attributed to inhaled asbestos fibres.
The patient had told Montague Murray that he was the only survivor from 10 others who had worked in his workshop.
However, unlike the Montague Murray case, which had aroused little interest, the death of Nellie Kershaw and its cause were widely reported. It then led to the government commissioning the Chief Inspector of Factories, Edward Merewether, and an engineer named Charles Price to report on workers’ health in the asbestos industry.
They found that among those who had been employed for more than five years, one third has asbestosis and of those who had been working for more than 20 years, four-fifths had the disease.
As a result of the report, the government introduced regulations in 1931 to control exposure to asbestos, as well as arrangements for regular medical surveillance of the workforce, and eligibility for compensation for factory workers with asbestosis.
A benefit commented on by workers in one factory after the new regulations were brought in, was that a clock on the wall had become visible for the first time.
In the early 20th century asbestos was considered a ‘magic mineral’. The ancient Chinese called asbestos the ‘fire rinsed cloth’ as they recognised it could be woven and it resisted high temperatures. Its current commercial exploitation started in the late 19th century with the development of steam powered machinery. The generation of heat and the need for insulation and fireproofing lead to it becoming widely used on ships, steam engines and in power generating plants.
Following the 1931 Regulations in the UK, the uses of asbestos continued to widen, particularly during and after the war years. In the early 1950’s Richard Doll, who had reported the link between smoking and lung cancer, was approached by John Knox who was the medical officer at the factory where Nellie Kershaw had been employed. He was concerned that he was seeing more cases of lung cancer in the workforce than was expected.
Doll then compared the death rate of those who had worked with asbestos in the factory, with what would be expected in men of the same age in the UK. He found that those who were employed in the factory were ten times more likely to have died from lung cancer. Against opposition from the factory management, Doll published his findings in 1955.
Five years later in 1960, Chris Wagner reported 33 cases of mesothelioma which is a cancer that most commonly affects the linings of the lung, pleura and less commonly, the lining of the abdomen. This was linked to exposure to crocidolite (blue) asbestos mining in South Africa at least 20 years earlier. Of particular importance was the fact that 18 of those cases had not worked directly with asbestos but instead, had been exposed in the neighbourhood of the mines. This showed that asbestos could cause mesothelioma even at low levels of exposure.
The risk of mesothelioma from neighbourhood exposure spelt the eventual death of the asbestos industry in the UK, as no level of exposure could be considered safe.
While control of asbestos exposure continued throughout the 1960’s with new regulations being put into place, the widespread use of asbestos-containing boarding continued unrecognised and unregulated into the 1970’s. This lead to the current epidemic of mesothelioma deaths in the UK.
This epidemic is anticipated to reach a peak in 2020 with an expected 2,500 deaths from mesothelioma, another 2,500 deaths from lung cancer and a further 500 deaths from asbestosis. This will occur primarily in carpenters who has sawed and drilled asbestos boarding, joiners, plumbers and electricians.
The incidence of mesothelioma in the UK is considered the highest in the world, followed by Holland and Australia. All forms of asbestos are now banned from import and use in the UK. However, because of the long latency of mesothelioma, an estimated 50-60,000 cases of mesothelioma will occur between 2020 and 2050, with 500 cases annually.
Despite the huge health risks, asbestos continues to be mined and used widely outside Europe and in the USA as a cheap material for insulation and fireproofing.