Row over workplace mineral fibre risks

UK communications giant British Telecom and NCU (now part of CWU), the union representing its engineers, had a long-running dispute over the risks posed by ‘man made mineral fibres’ (MMMF). The union questioned a company “assurances about the absence of risk,” which led BT to commission two external scientists to assess the evidence, both of which concluded the fibres posed no serious risk. One, Dr Robert Murray, noted strayed from a scientific analysis of the evidence, instead accusing unions of stirring up unjustified concern about fibre risks. He noted: “The subject of fibres has in the past been so charged with emotion that there is little hope of a detached scientific view being taken. This is evident from the literature provided by the other unions, especially the GMBATU [now GMB], which is full of selective quotation, misrepresentation and downright errors and is illuminated by the benefit of hindsight.” He added: “I think that existing evidence is sufficient to demonstrate the problem of MMMF is an industrial relations one rather than a medical one.” Murray was later discredited after it was revealed he had worked as a hired gun for the asbestos industry. The MMMF health concerns at BT led NCU to introduce a ban on work with MMMF in the mid-1980s, which remained in force until January 1987 when the union negotiated safety improvements. Roger Darlington, the NCU’s health and safety officer, said a recent Health and Safety Executive (HSE) statement on lung cancer risks linked to asbestos “vindicates the union position.” Within six years, the US safety authorities had fought of industry challenges and had mineral fibres added to the list of cancer-causing substances in the official Annual Report of Carcinogens [see: Industry sparks controversy over glass fibre and cancer, 1994].

BT v NCU: Cancer, Hazards, number 17, February 1988.

 

Workplace watchdog HSE has no policy on workplace cancer

The UK’s occupational exposure standards for hazardous substances frequently lag way behind those elsewhere. The Health and Safety Executive (HSE) is particularly remiss on occupational carcinogens, according to Hazards magazine. “The HSE has no overall policy on carcinogens,” it notes. Whereas US and Swedish authorities had called for exposures to carcinogens to be reduced as far as is technically feasible, HSE “will not even indicate if a substance is suspect.”

Substandards: Some HSE recommended limits compared to other standards, Hazards, number 16, December 1987.

 

Dispute over DMF solvent cancer risks

A major chemical producer challenged a study raising cancer concerns about occupational exposure to the solvent Dimethylformamide (DMF) – but relied on an internal study it had not published in its defence. DMF has been used widely in laboratories, the manufacture of synthetic textiles and artificial leather, as a solvent for dyes and pigments and in other processes including the production of resins, rubbers and polymers. US researchers, prompted by concerns raised by the Amalgamated Clothing and Textile Workers’ Union, investigated three cases of testicular cancer that had occurred at a leather tannery. All three workers had been involved in dyeing the leather and had worked in the tannery for several years. The authors concluded the cases could be linked to DMF exposure. It followed an earlier study which linked two cases of testicular cancer to DMF exposure. A response to the union-spurred article from US chemical giant DuPont, a major user of DMF, challenged the findings, saying the company’s own study of exposed workers found no excess of testicular cancer. The DuPont study’s findings were unpublished however. The US government’s workplace health research agency, NIOSH, had previously recommended an investigation into the possible cancer causing properties of DMF.

S Levin and others. Testicular cancer in leather tanners exposed to dimethylformamide, The Lancet, volume 330, number 8568, page 1153, 14 November 1987.

JL Chen and GL Kennedy, Dimethylformamide and testicular cancer (reply), The Lancet, page 55, volume 331, numbers 8575-8576, 9 January 1988.

Also see NIOSH September 1990 summary of the studies.

Cancer causing vehicles encouraged in UK coal mines

The UK encouraged the use of diesel-exhaust belching Free Steering Vehicles (FSVs) in UK coal mines, at a time US authorities and unions were discouraging their use because of a potential cancer link. ‘Unstitching the pit rules’, a feature in hazards magazine, notes: “The Mines Inspectorate’s view is that FSVs could help to reduce the accident rate in haulage, but neither British Coal nor the Inspectorate seem to have seriously considered the health hazard of diesel exhaust fumes. The [US] National Institute for Occupational Safety and Health (NIOSH) as long ago as 1976 that diesel powered vehicles should not be introduced further into US coal mines. NIOSH was concerned about the known cancer-causing agents in diesel exhaust emissions and the potentially serious health effects of exhaust emissions combined with coal dust. The United Mineworkers of America have banned diesel FSVs from all union-organised mines.” In June 2012, IARC rated diesel exhaust as a group 1 human carcinogen.

Unstitching the pit rules, Hazards, number 14, June 1987.

Animal tests not a good guide to human cancer risk

This paper considers that animal cancer tests could not predict absolute cancer risk in humans. It argues that natural carcinogens exist in food and drink at higher levels than those such as pesticides in work and wider environments and says these present minimal risks.

Ames BN, R Magaw, and LS Gold. Ranking possible carcinogenic hazards, Science, volume 236, number 4799, pages 271–280, 17 April 1987.

 

Cancer expert didn’t tell workers of chrome cancer risk

A lung cancer expert who was a regular visitor to a UK chromium plant and who was heavily involved in official expert reviews of the high lung cancer risk posed by chromium compounds, neglected to point out this association to the workers in the factory. Dr P Lesley Bidstrup was not only a member of the government’s Industrial Injuries Advisory Council (IIAC), she had regular contact with workers at the Eaglescliffe plant of British Chrome and Chemicals. But the 500 workers were unaware she had published extensively on the deadly lung cancer risk in the industry. Dr Bidstrup has spent more than 30 years monitoring the health of workers in the UK chrome industry and had reported a lung cancer incidence 3.6 times the norm. A report she co-authored in 1956 concluded lung cancer was an occupational disease in the chrome industry. The plant was the recipient of dozens of Health and Safety Executive (HSE) improvement notices in the 1970s. Modifications were made, with Dr Bidstrup writing in the British Journal of Industrial Medicine in the late 1970s that these resulted in “an appreciable reduction of the excess risk from lung cancer.”  It was only in the 1980s that unions at the plant became aware of this cancer risk, organising training courses and pressing for improvements. Hazards magazine noted: “Publishing articles in prestigious scientific journals may be very good for the authors, but results of research need to be in the hands of workers for real improvements to be made.”

Chrome: Dazzling but deadly, Hazards, number 12, January 1987.

PL Bidstrup and RAM Case. Carcinoma of the lung in workmen in the bichromates-producing industry in Great Britain, British Journal of Industrial Medicine, volume 13, pages 260-264, 1956.

Some work lung cancers ‘prescribed’, most not

The Industrial Injuries Advisory Council (IIAC) recommended in December 1986 for “occupational lung cancer to be prescribed” for certain substances in certain circumstances. Prescription means a qualifying individual may qualify for state industrial disease compensation. IIAC recommendations, which were accepted by government, called for the inclusion lung cancer in tin miners, workers exposed to BCME (bis-chloromethylether) during manufacture of CMME (chloromethylmethylether) and workers exposed to chromates such as zinc, calcium and strontium chromate. IIAC rejected other proposed occupations, such as iron ore miners, workers exposed to beryllium, coke oven fumes, rubber fumes or man made mineral fibres and foundry workers, despite strong evidence of a lung cancer risk for most of these jobs. IIAC’s rules have a higher barrier to acceptance – cancers but occur at double the expected rate, something unlikely for most occupational cancers.

 

Occupational Lung Cancer, IIAC, December 1986.

HSE ignoring cancer risks of methylene chloride

While US authorities were warning of the potential cancer risk from exposures to methylene chloride (dichloromethane), the UK Health and Safety Executive (HSE) had nothing to say for itself. Pointing out at the US Environmental Protection Agency had declared methylene chloride a “probable human carcinogen”, Hazards magazine said HSE had “said nothing.” It added: “But we know the UK government ‘Expert Committee on Carcinogenicity’ where there are no trade union representatives have recently declared methylene chloride to be a human carcinogen.” Hazards said the new exposure limit of 100 parts per million introduced in January 1886 “must now be reduced” because of the emerging evidence of a cancer risk. In 1999 IARC said there was sufficient evidence to conclude the solvent was carcinogenic in animals and said it was “possibly carcinogenic to humans.” In 2014, the UK was the only European Union government to request a derogation for certain processes from the EU wide ban on methylene chloride’s use a paint stripper.

Toxic paint stripper: Methylene chloride, Hazards, number 10, September 1986.

US guidance on asbestos risk to mechanics

The US Environmental Protection Agency (EPA) issued guidance to help motor mechanics avoid asbestos exposure from brake and clutch linings. In August 2003, the law firm of Morgan, Lewis & Bockius LLP filed a Data Quality Act (DQA) petition with EPA challenging the agency’s 1986 publication. The attorney from Morgan, Lewis & Bockius asked the EPA to either stop disseminating the asbestos disease prevention guide, and either alert the public that the booklet is scientifically outdated, or review the latest scientific literature and update the booklet. The company did not reveal the identity of its client, although it subsequently became clear these were firms defending asbestos cases compensation cases. EPA caved in, replacing the 15 page document with a pared back two page draft replacement. Industry backed scientists then pitched in, claiming a revision should acknowledge their findings that asbestos from brake linings was “innocuous.” According to David Michaels and Celeste Monforton “defendants in litigation involving asbestos-containing friction products have successfully modified an official EPA document which they viewed as “alarmist and inflammatory.”

Guidance for preventing asbestos disease among motor mechanics, US EPA, June 1986.

David Michaels and Celeste Monforton. How litigation shapes the scientific literature, Journal of Law and Policy, volume 15, issue 3, pages 1137-1169, 2007.

Improved work methods for mineral fibres delayed for eight years

Following a lengthy union campaign, the Health and Safety Executive (HSE) in 1984 recognised that ‘mineral wool’ (glass, rock or slag insulation wools, made from mineral fibres) could no longer be regarded as ‘nuisance dusts’. In 1986, HSE issued a guidance note (EH46) tightening up working practices to reduce the risks, with exposures to be kept below a control limit of 5mg/m3.  The precautions had been delayed for eight years at this point – they had been adopted by an HSE working party in 1979. In 1994, mineral fibres were added to the US government’s official list of recognised human carcinogens.

Exposure to mineral wood, guidance note EH40, June 1986.

Report in Hazards magazine, number 14, June 1987.

A continually-updated, annotated bibliography of occupational cancer research produced by Hazards magazine, the Alliance for Cancer Prevention and the International Trade Union Confederation (ITUC).