Cancer all-clear for night work was based on ‘bad science’

Photo: Jawad Qasrawi
OLD PROBLEM The Oxford University study giving night work a cancer all-clear included many retired workers who’d not worked nights for years. But you need to look at younger workers with a recent long-term history of night work if you want to spot raised breast cancer rates.

An Oxford University study that concluded the classification of night work as a cause of breast cancer in women is no longer justified was based on ‘bad science’, top researchers have warned.

The large scale ‘meta-analysis’, published online on 6 October 2016 in the Journal of the National Cancer Institute (JNCI), concluded “night shift work, including long-term night shift work, has little or no effect on breast cancer incidence.” It added the International Agency for Research on Cancer’s (IARC) ranking of night work as a ‘probable’ cause of breast cancer in women “is no longer justified.”

But three of the most respected epidemiologists on night work and breast cancer have now said they “fully disagree” with this conclusion, noting a succession of methodological flaws in the research “invalidate” its conclusions.

Harvard Medical School epidemiologist Eva Schernhammer told Hazards magazine that given the Oxford study’s “bad science”, it was “not surprising” it found no effect. In a detailed criticism of the paper, published online on 15 December, she said the JNCI paper’s many shortcomings “preclude it from making the conclusion that there is no association between night work and breast cancer risk.”

Johnni Hansen, a researcher with the Danish Cancer Society, was equally unimpressed. “They base their conclusion on a poor study, but even worse is that their conclusion may hinder preventive initiatives for night workers,” he said.

Richard Stevens, of the University of Connecticut medical school, who has written influential papers on the topic with both Schernhammer and Hansen, was blunt. “Why was the paper written in the first place?” he asked.

The main cohorts in the Oxford study, which was financed by the Medical Research Council, the Health and Safety Executive (HSE) and Cancer Research UK (CRUK), were “worryingly old”, with many over retirement age, and the follow up was “unusually short”, Hansen said.

The risk of women developing breast cancer appears to wane in the years after night working ends, so studying retired workers without recent exposures misses the point and the cancers, said Schernhammer. She said the higher risk is seen in women with long exposures – at least 15 years – early in their careers. Hansen added the authors behind the JNCI study should have recognised the possibility of ‘truncation bias’ in their analysis.

Night work was sometimes defined so loosely in the study participants, a single night shift might have seen a worker added to the ‘exposed’ group despite facing minimal exposure and risk. The JNCI paper also discounted case-control studies and those exploring the mechanism behind a possible association.

According to Stevens, the JNCI meta-analysis “excluded case-control studies, of which there are many, for no good reason.”

He added that studies considering the biological mechanisms give a valuable insight into why and where you might look for an association. Understanding the process, something integral to his own research, was important, he indicated.

Stevens, Schernhammer and Hansen, together with Scott Davis, a professor of epidemiology in the University of Washington’s School of Public Health, are the stand-out epidemiologists on night work and breast cancer.

Not one of them was asked to review the paper. “We are the four epidemiologists who have been working for by far the longest on the epidemiology of night work and breast cancer,” said Stevens, who is dismayed the Oxford study, led by molecular epidemiologist Ruth Travis, found its way in to a high visibility journal like JNCI.  “Any of the four of us would have quickly noticed the severe flaws of the Travis paper and pointed them out to the editors of JNCI.”

He said it was “absurd” that the night work association with breast cancer was being dismissed on the back of a “troubling” paper by “a distinguished group of experienced researchers who should have known better.”

The JNCI study’s lead author, Ruth Travis, declined an invitation from Hazards to address the detailed criticisms of the study.

Australian study links diesel exhaust to high lung cancer rates in miners

Diesel exhaust exposures are leading to high rates of fatal lung cancers in underground miners, according to a new study.
Researchers from Australia and the Netherlands found underground production workers, including diesel loader operators and shotcreters, face the highest risk. They called for strict controls to limit their exposure.

The study, published online in the journal Occupational and Environmental Medicine, marks the first phase of an investigation into conditions in Australian mines. Using Department of Mines and Petroleum data from 2003 to 2015 and other studies, it modelled the average levels of exposure among employees in a range of occupations on Western Australian mine sites. It then estimated the number of lung cancer deaths caused by those levels with stark results.

“If somebody were to be exposed as an underground miner, we saw that that person would be exposed to on average 44 micrograms per cubic metre (µg/m3),” said lead investigator Dr Susan Peters from the University of Western Australia.

At this exposure level over a 45-year working lifetime, compared to the general population the miners would have 38 extra lung cancer deaths per 1,000 males. Above-ground mine workers were found to face a lower but still elevated risk, with an average exposure of 14 µg/m3 over 45 years causing about 5.5 additional lung cancer deaths per 1,000 workers.

The paper concludes “exposure levels in the contemporary Australian mining industry are still substantial, particularly for underground workers. The estimated excess numbers of lung cancer deaths associated with these exposures support the need for implementation of stringent occupational exposure limits for diesel exhaust.”

The International Agency for Research on Cancer (IARC) classified diesel exhaust as a  top rated ‘Group 1’ human carcinogen in 2012.


IARC scientists defend glyphosate cancer ranking

The World Health Organisation (WHO) agency that labelled the world’s most widely used herbicide a probable cause of cancer in humans has hit back after the agrichemical industry responded with a savage attack on its science and funding.

The International Agency for Research on Cancer (IARC) panel of scientists made the evaluation on glyphosate, the chief ingredient in Monsanto’s Roundup brand, in March last year. The IARC ranking prompted British union federation the TUC to call on safety reps to ensure members were not exposed to the pesticide. The global farming union IUF called for a ban.

For its part, CropLife America, the industry’s lobbying group, demanded that US authorities repudiate the IARC ranking and cut funding to the UN agency. A 24 October 2016 statement from the group said it “welcomes the interests of a variety of Congressional committees that may provide oversight on all manner of pesticide policy matters ─ including the interest shown about IARC funding.”

Monsanto labelled the IARC findings as “junk science,” and claimed the IARC members are part of an “unelected, undemocratic, foreign body.”

The attack came as a surprise to the IARC working group, which is comprised of recognised independent experts from scientific agencies around the world, including the US. Aaron Blair, a scientist emeritus at the US National Cancer Institute, served as chair of the IARC team.

Australian epidemiologist Lin Fritschi, a member of the IARC working group, said the team’s work was solid and the industry attacks on the team’s credibility are unwarranted. “I definitely wasn’t expecting anything at all,” said Fritschi, who specialises in the occupational causes of cancer.

“We were independent and just looked at the science. We had strict rules on what was admissible and came to a conclusion based on that evidence. We made the right decision based on the evidence.”

Fritschi, a distinguished professor at Curtin University in Australia, added: “The people most at risk are people who use glyphosate a lot, such as farmers and gardeners, and they are the ones who should try and reduce their use.”

Why are preventable occupational and environmental breast cancer risks ignored?

Breast Cancer Awareness Month has provided a welcome focus on a condition that has risen sharply over the last 40 years, but campaigners are concerned the UK government and breast cancer charities are resolutely ignoring the host of preventable occupational and environmental causes of the condition.

To address this, campaign group From Pink to Prevention has produced a new ‘toolkit’ with an interactive webpage, posters and an action guide. As a first step it says it wants the annual awareness event renamed ‘Breast Cancer Prevention Month’.

The campaign says it “is disturbed to discover the failure of leading breast cancer charities to inform women about all the risk factors, and questions the exclusive focus on lifestyle factors (alcohol, exercise and smoking) and the 10 per cent of cases linked to genetic factors, to the exclusion of the impact toxic chemicals are having on the health of every single one of us.”

From Pink to Prevention adds: “Given that the vast amount of existing research into lifelong (womb to grave) exposures to environmental and occupational risk factors and the fact that breast cancer is a hormonal disease, this selective narrative could be seen as a barrier to official and public recognition of the right to know.”

Green Party MP Caroline Lucas is backing the campaign for a greater emphasis on preventive action. Her early day motion notes “that along with lifestyle causes, better treatment and care, women’s everyday exposure to environmental and occupational toxicants is the crucial missing piece of the breast cancer jigsaw and the public’s right to know demands urgent attention.”

More information

Unions expose Samsung’s ‘medieval practices’ worldwide

The global reach of Samsung’s ruthless pursuit of profits impacts dangerously on the lives of its workers, a new report has charged.

Samsung – Modern tech medieval conditions, published by the International Trade Union Confederation (ITUC) and the global union IndustriALL, reveals how the company’s ‘corporate greed’ is causing problems from cancer to brutal working conditions and job insecurity throughout the multinational’s supply chains.

“From denying justice to the families of former employees who died from cancers caused by unsafe workplaces, to dodging tax and engaging in price-fixing cartels, one thing is constant: Samsung’s corporate culture is ruthlessly geared towards maximising profit to the detriment of the everyday lives of its workers,” said Sharan Burrow, ITUC’s general secretary.

The report’s publication came ahead of a 7 October rally at Samsung’s Seoul headquarters. The protest, on World Day for Decent Work, was organised by the Seoul-based health and safety campaign group SHARPS (Supporters for the Health and Rights of People in the Semi-Conductor Industry).

“Corporate greed, corporate bullying cannot be tolerated – it’s time for a global rule of law to guarantee globalisation with fair working conditions, with rights, minimum wages on which people can live with dignity and safe and secure work,” said Jyrki Raina, general secretary of IndustriALL.

Sharan Burrow said: “Beginning with Samsung, we have begun to expose corporate greed and the failure of the world’s biggest corporations to account for abuse in their supply chains – from union busting, poverty wages, insecure and unsafe work, to forced overtime, informal work and modern slavery.”

The ITUC leader added: “It doesn’t end here: we will keep up the pressure for reform and the rule of law, we will engage with pension funds managing workers’ capital regarding investment strategies and we will stand with workers everywhere as they demand the rule of law. We will end corporate greed.”

The ITUC is petitioning Samsung to end worker abuse and to abolish its no-union policy.



UK union group probes rare brain cancer cluster

Audrey Musson is one of five widows of Staveley Chemicals workers who died from the rare brain cancer, glioma. Pictured with a photo of her late husband Neville. Photo: Sheffield Star

The families of five chemical plant colleagues who all died of a rare type of brain cancer have said they want answers. The cluster of glioma cases, affecting men who all worked at Staveley Chemicals in Derbyshire, was unearthed by the Chesterfield-based Trade Union Safety Team (TRUST).

The ongoing investigation by the trades council-linked TRUST, working with experts from Stirling University’s Occupational and Environmental Health Research Group, is exploring links with chemicals handled at the site.

TRUST’s John Knight, who with colleague Joanne Gordon is leading the research, said: “Having done some initial research we have found that in the normal population, 8 in every 100,000 people would be expected to die from this rare condition, here we have at least four in a localised vicinity. This together with the fact that the men died within a few years of each other makes it very unusual.”

He added: “As part of our in-depth research we will also look into possible causes of this rare brain cancer, including any exposure to hazardous substances such as known carcinogens like benzene and mercury.”

Audrey Musson, the widow of Staveley glioma victim Neville Musson, said she hopes a new investigation into any links between the deaths and the chemical plant may give them, and potentially others, some answers.

She added: “They all died of these brain tumours, so alarm bells started ringing. The researchers now are trying to find a link with the chemicals. It’s so upsetting, but we’ll see what comes out of this. If there’s anybody else out there whose husbands had brain tumours, we’d like anybody to come forward.”

TRUST’s Joanne Gordon said: “We will do our level best to get to the bottom of what is a very concerning case.”

In a statement, the last owners of Staveley, French firm Rhodia, said it was sympathetic to the concerns of the families and would respond if reliable data or new findings became available.


US industries queue up to defend their toxins

A new US chemical safety law has triggered an immediate response from chemical producers – a helter-skelter rush to ensure their favourites are the back of the queue for official scrutiny.

The Frank R Lautenberg Chemical Safety Act for the 21st Century, passed into law in June this year, gave the US Environmental Protection Agency (EPA) the authority needed to evaluate and regulate the tens of thousands of commercial chemicals it oversees in the US.

The law was hailed as a more transparent ‘new risk-based safety standard’, replacing the Toxic Substances Control Act’s (TSCA) cost-benefit analysis that required EPA to include commercial considerations when deciding on chemical restrictions.

“But many industry group comments suggest we’ve not heard the last of the old argument,” writes chemical safety journalist Elizabeth Grossman. She says on the ‘keep off’ list are top causes of occupational cancer, including asbestos, benzidine dyes and vinyl chloride monomer.

While industry groups are actively defending the toxic substances they produce or use, other stakeholders are calling on EPA to make these high risk substances a priority. Senator Barbara Boxer, the Senate’s Environment and Public Works Committee’s ranking Democrat, has written to EPA administrator Gina McCarthy asking that asbestos be among the first 10 chemicals the Lautenberg Act considers.

“The EPA’s proposed choices are due by mid-December,” writes Grossman. “They will reveal whether the Lautenberg Act will move to restrict hazardous chemicals of great concern to workers and work sites.”

Firefighters’ guide to occupational cancer prevention

The UK  firefighters’ union FBU says occupational cancer is a ‘serious threat’ for firefighters. In response, the union has produced an initial guidance document which highlights the basic principles to follow to prevent unnecessary contamination with smoke, fumes, chemicals and other hazardous substances before, during and after incidents.

The union says FBU officials will be asked to raise these issues with management and at health and safety committee meetings. It adds that some fire and rescue authorities have already taken steps to address the problem, but says ‘our aim is that it will soon be on the agenda in every brigade.’

FBU says Contaminants – protection against cancer, which includes a 10-point action plan, is only initial advice. “The FBU is looking at medium and longer term options,” it notes. “As a member you can start to make a difference today by adopting the principles suggested in this document.”

Samsung lung cancer deaths were ‘occupational’

The lung cancer deaths of two former Samsung Electronics semiconductor factory workers have been accepted as work-related by the Korea Workers’ Compensation and Welfare Service (KCOMWEL).

The cases are the first officially recognised cases of occupational lung cancer among Samsung Electronics semiconductor workers. The ruling is expected to prove controversial, with lung cancer not included among diseases Samsung Electronics has acknowledged as linked to semiconductor work.

A 1 September statement from the human rights group Banollim stated that KCOMWEL “issued final rulings on 29 and 30 August recognising the lung cancer deaths of Lee Gyeong-hui and Song Yu-gyeong as industrial accidents.”

Lee died aged 38 and Song aged 43. KCOMWEL’s decision came over two years after the family members applied for bereavement benefits. According to the ruling, “the deceased appear to have been continuously exposed to arsenic while performing their duties, and given that their diagnoses of and deaths from lung cancer came at an early age in the absence of other risk factors, a connection with their duties is recognised.” Arsenic is a known cause of lung cancer.

An epidemiological report for Lee’s case said there was evidence of four Samsung Electronics partner companies attempting to hinder KCOMWEL’s investigation. At the time, the semiconductor production line where Lee and Song worked had been outsourced to current Samsung partners.

Banollim said: “During this investigation, Samsung Electronics claimed not to use carcinogens, but there was no mention of arsenic in the materials it presented as evidence.”

The campaign for Samsung victims, SHARPS, said the KCOMWEL ruling meant the Korean authorities now recognise officially eight conditions as occupationally related to semiconductor work: Leukaemia; lymphoma; aplastic anaemia; breast cancer; chronic inflammatory demyelinating polyneuropathy; brain cancer; ovarian cancer; and lung cancer.

Stop Samsung blog. The Hankyoreh. Equal Times.


US union campaign to tackle cancer risks from firefighting

US firefighters are more at risk for cancer than the general population, according to union research forming part of a high profile campaign for fairer compensation laws and prevention measures.

The International Association of Fire Fighters (IAFF)  report says the risk is “significantly higher for firefighters than the general population” because when fighting fires they are apt to come into contact with synthetic materials such as plastics, foam and coatings that contain carcinogens. The report cites a 2013 study by the US government’s National Institute for Occupational Safety and Health (NIOSH) that found firefighters have a 14 per cent increased risk of dying from cancer when compared with the general population.

“Our communities and their legislators need to understand how PTSD and cancer are impacting their firefighters over the course of a long and dedicated career protecting the public,” IAFF president Harold Schaitberger said in a statement. “New advanced protocols are needed to help prevent PTSD and cancer from taking hold, and more elected officials need to step up and support laws that help firefighters afflicted with these hidden hazards.”

The IAFF has run a highly successful campaign for state-based presumptive legislation for firefighters who contract cancer, meaning in most instances firefighters developing a related cancer qualify for compensation automatically. In April, Idaho became the 34th state to introduce these presumptive protections. The union has also developed occupational cancer prevention resources.

The study also found firefighters were at a much greater risk of post-traumatic stress disorder (PTSD).


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).