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.

IARC says mineral fibres may cause lung cancer

An International Agency for Research on Cancer (IARC) study of the health risks of man-made mineral fibres has concluded the findings do suggest a possible link with lung cancer. After over a decade of pressure from unions and mounting animal evidence of a cancer risk, the industry embarked on two studies, in Europe and the USA. IARC concluded that after reviewing the evidence including these two industry papers, they “support the inference that MMMF – as present in the environmental conditions of early slag-wool/rock-wool production – may have played a role in the causation of lung cancer.”

R Saracci. Contributions to the IARC (International Agency for Research on Cancer) study on mortality and cancer incidence among man-made mineral fiber production workers, Scandinavian Journal of work Environment and Health, volume 12, supplement 1, pages 5-93, 1986. See the mineral fibre themed supplement.

Exhaust fumes linked to bladder cancer

Lorry drivers and other workers exposed regularly to vehicle exhaust fumes are at greater risk of contracting bladder cancer, a US study found. Researchers investigated about 2,000 cases of bladder cancer in men and attempted to identify associations with their work. “Our findings indicated that males usually employed as truck drivers or deliverymen have a statistically significant, 50 per cent increase in risk of bladder cancer,” the study found. “Overall, a statistically significant trend in risk with increasing duration of truck driving was observed. This trend was particularly consistent for drivers first employed at least 50 years prior to diagnosis. Of these, truck drivers employed 25 years or more experienced a 120 per cent increase in risk. Elevations in risk were also suggested for taxicab and bus drivers.” In June 2012, IARC rated diesel exhaust fume as a group 1 human carcinogen.

DT Silverman and others. Motor exhaust related occupations and bladder cancer, Cancer Research, volume 46, number 4, part 2, pages 2113-2116, 1986.

Meat industry may cause cancer in women

A US study of over 7,000 women union members in the meat industry found that those working in supermarket meat departments had a 3-fold increased risk of death from myeloid leukaemia and non-Hodgkin’s lymphoma. These women, together with women employed in chicken slaughtering factories and meat-packing plants (slaughterhouses), also had a greater risk of lung cancer than those employed in non-meat work. The authors note: “The findings need to be confirmed, but the excess of lung cancer we observed is consistent with reports of an excess of lung cancer in butchers and meatcutters from the analysis of national statistics over different periods in England and Wales, Denmark and Sweden, and also from other studies.”

ES Johnson and others. Occurrence of cancer in women in the meat industry, British Journal of Industrial Medicine, volume 43, number 9, pages 597-604, 1986.

Cumulative exposures mean chrome standard doesn’t protect

US researchers who investigated the increased risk of lung cancer in workers exposed to chromium VI found that those most at risk, with over three times the risk of dying from the disease, were those who had worked longer in the plants. The authors said this was probably due to their higher cumulative exposure. Because of this, they suggested exposure limits were insufficiently protective, as they didn’t take account of this cumulative effect, noting “these results suggest a potential excess risk of death from lung cancer among US workers exposed to the current permissible exposure limit (PEL) for hexavalent chromium.”

ER Braver and others. An analysis of lung cancer risk from exposure to hexavalent chromium, Teratogenesis, carcinogenesis and metagenesis, volume 5, issue 5, pages 365-378, 1985.

 

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).