Farmworkers who have a high pesticide exposure event – such as a spill – are more likely to experience molecular changes to their DNA that may lead to prostate and other cancers, according to a large study of pesticide applicators.
Environmental Health News reports the research, part of the ongoing US Agricultural Health Study that is monitoring the health of more than 57,000 private and commercial pesticide applicators, adds to growing evidence that high exposure to certain pesticides may spur prostate and other cancers in people handling the chemicals.
Researchers have long suspected pesticides may play a role in the elevated cancer rates among farmers and others who apply pesticides. Earlier findings of the same study have reported higher rates of prostate cancer linked to pesticide exposures.
The current paper, published in the journal Environmental and Molecular Mutagensis, included 596 male pesticide applicators. It found men who experienced a “high pesticide exposure event,” meaning a spill or other accident that would leave them highly exposed, were more likely to have elevated levels of DNA methylation in a gene linked with increased prostate cancer risk.
This type of exposure to pesticides would be “unusually high,” said lead author Dr Jennifer Rusiecki, an assistant professor of medicine at Uniformed Services University in Maryland, USA.
JA Rusiecki and others. High pesticide exposure events and DNA methylation among pesticide applicators in the agricultural health study, Environmental and Molecular Mutagensis, volume 58, number 1, pages 19-29, January 2017.
Much of the past effort against cancer has fixated on the wrong enemies, with the wrong weapons, a leading expert has said.
US professor Devra Lee Davis said while effort was focus internally on genetic factors, the external influences – what we breathe, drink, eat and absorb through our skin – is being overlooked. Writing in The Hill, she said “the great majority of cases of cancer occur in people born with healthy genes as a result of carcinogenic exposures at work, home, and school.”
But she said the failure to recognise this has “less to do with science, and more to do with the power of highly profitable industries that rely on public relations to counteract scientific reports of risks. Studies of identical twins tell us that most cases of cancer do not arise because of inherited defects. Only one in 10 women who develop breast cancer is born with defective genes. This means that most cases come about because of ways that our healthy genes interact with the world around us.”
She added: “The list of workplace causes of cancer provides a litany of largely ignored factors. Women who work at night – like nurses or those who work in electronics – have lower levels of melatonin and higher rates of breast cancer. Men who work with chemicals or electromagnetic fields have higher rates of brain cancer and leukaemia. Those who work with wood dust and formaldehyde have higher rates of nasal cancer.”
The professor, who authored the The secret history of the war on cancer a decade ago, concluded: “If we had acted on what has long been known about the industrial and environmental causes of cancer when this national war first began, millions of lives could have been spared — a huge number of casualties for which those who have managed the effort against the disease thus far must answer.”
The woman chosen by president Donald Trump and now confirmed as the US ambassador to the United Nations has launched a scathing attack on the international body which could embolden an industry lobby angry at the UN’s role in assessing chemical cancer risks.
During her confirmation hearing , Nikki Haley said: “When we look at the United Nations, we see a chequered history… any honest assessment finds an institution that is often at odds with the American national interest and American taxpayers.”
Haley was signalling that international agencies will have to answer to an ‘America First’ administration hostile to global policymakers. One already in the crosshairs is the International Agency for Research on Cancer (IARC), which is under the purview of the UN’s World Health Organisation.
House Oversight and Government Reform Committee chair Jason Chaffetz said the IARC has a “record of controversy, retractions, and inconsistencies” and asked why the National Institutes of Health has spent $40 million since 1992 to fund it. Chaffetz expressed concern that the IARC “influences American policymaking, even though IARC avoids having to meet the strict scientific standards and government scrutiny afforded to science advisory committees in America.”
The statement was straight from the industry playbook. Speaking as he announced its latest salvo, a ‘Campaign for Accuracy in Public Health Research‘ launched on 25 January 2017, ACC president and CEO Cal Dooley said: “Public policy must be based on a transparent, thorough assessment of the best available science.” He continued: “Currently, IARC’s monographs do not meet this standard though U.S. taxpayers foot the bill for over two-thirds of the international program’s budget.”
This prolonged attack has however been refuted by many of the world’s top research scientists, including leading US cancer epidemiologists.
Their June 2015 paper in Environmental Health Perspectives, a respected peer-reviewed journal supported by US government’s National Institute of Environmental Health Sciences (NIEHS), noted: “Debate and criticism facilitate self-correction and a check on the validity in science. We are concerned, however, that the criticisms expressed by a vocal minority regarding the evaluations of a few agents may promote the denigration of a process that has served the public and public health well for many decades for reasons that are not supported by data.”
The paper concludes “as a group of international scientists, we have looked carefully at the recent charges of flaws and bias in the hazard evaluations by IARC Working Groups, and we have concluded that the recent criticisms are unfair and unconstructive.”
British workers exposed to the elements account for 2 per cent of cases of the most deadly form of skin cancer, a new study has concluded. Exposure to harmful ultraviolet (UV) rays from the sun while at work leads to one death and five new cases of malignant melanoma every week, the authors found.
Construction workers are most at risk of malignant melanoma (44 per cent of deaths) followed by those who work in agriculture (23 per cent). Police, the armed forces and other public administration workers are also susceptible, according to the study published online in the British Journal of Cancer. The researchers estimated there are 48 deaths and 241 cases of melanoma skin cancer each year in Britain caused by people being exposed to the sun while working.
Dr Lesley Rushton, lead researcher from Imperial College London, said: “We’ve shown previously that people often don’t understand the risks of damage caused by sun in the UK. But this research shows you don’t have to work in the Mediterranean or a traditionally sunny country for the sun to damage your skin.”
She added: “It’s important to get to know what your skin is normally like, and to tell your doctor if you notice any changes to how your skin looks or feels. Skin cancer can appear as a new mole or mark, or it can be a change to something you’ve had for a while. Now that we have a clearer picture of the extent of the damage caused, employers need to make sure they take sun exposure at work seriously and work out how to reduce it.”
The authors found the main industries “of concern” were construction, agriculture, public administration and defence and land transport. Construction workers accounted for 21 deaths and 101 cases of malignant melanoma. “We estimate that 2 per cent of all cutaneous malignant melanoma in Britain can be attributed to occupational exposure to solar radiation giving approximately one death and five new cancers per week,” they concluded. “This highlights the need to develop appropriate strategies to reduce this burden.”
Lesley Rushton and Sally J Hutchings. The burden of occupationally-related cutaneous malignant melanoma in Britain due to solar radiation, short communication, British Journal of Cancer, advance online publication, 17 January 2017 [abstract].
Some workers who make or work with the endocrine-disrupting chemical bisphenol-A (BPA) have levels in their bodies 1,000 times higher than the general public, a study by a US government agency has found.
The research led by the National Institute of Occupational Safety and Health (NIOSH) found, on average, these workers had 70 times more of the chemical in their bodies than the general public, levels well above what has been shown to affect reproduction. BPA is also linked an increased risk of breast cancer and other health effects.
A total of 77 workers at six US companies that make BPA, BPA-resins or BPA-filled wax provided urine samples after two consecutive days at work. The average total BPA in their urine was 70 times higher than a study of US adults, according to findings published in the Annals of Work Exposures and Health.
One worker’s levels spiked up to 18,900 micrograms per gram of BPA at the end of the shift on the second day of work. The median level of BPA in the general public is a little less than 2 micrograms per gram.
NIOSH’s Cynthia Hines, lead author of the study, said there are no workplace exposure limits for BPA in the US. “If we clearly had an exposure level – for example something like lead – we’d go the extra measure to make them aware of their risk with those levels,” Hines said. “With BPA, we don’t have standards.”
She said the researchers did send general advice to the companies and workers on how to reduce exposure. Industry has argued that the body passes all accumulated BPA within a day, and so current exposures cause no harm. The federal study, which consistently showed higher levels after the second day of work, undercuts that argument.
In a major victory for Canada’s trade union movement, the country’s federal government has announced a ban on the import, export, manufacture and use of asbestos.
While Canada banned asbestos mining in 2012, imports of asbestos-containing products have been increasing over the past five years, and some asbestos-containing products have also been exported from Canada.
Speaking after the 15 December 2016 announcement, Sharan Burrow, general secretary of the global union confederation ITUC, said “we congratulate the Canadian trade union movement for this success, and the government’s move will increase pressure on other countries which still have not implemented a ban. Tens of millions of people are exposed to asbestos, and all governments need to act as Canada now has to stem the appalling toll of death and disease.”
Hassan Yussuff, president of the Canadian Labour Congress (CLC), said: “Canada’s unions, along with survivors and health advocates, have been working hard for this ban for decades. We know this will strengthen occupational health and safety protections for workers and make workplaces and public spaces safer for everyone”.
CLC is continuing to press the government for a national registry of people affected by asbestos-related diseases, the implementation of a comprehensive health response covering early detection and treatment as well as measures to protect workers in situations where asbestos is present such as building renovations.
The CLC has also called for the government to support demands at the United Nations that chrysotile asbestos be added to the list of especially hazardous materials regulated under the Rotterdam Convention.
UK union Unite has joined industry representatives, academics and safety and health professionals signing up to a 12-month voluntary plan of action to tackle the risks from inhaling silica dust at work.
Respirable crystalline silica (RCS) The potentially deadly mineral is encountered in a wide range of jobs from construction, to mining, ceramics, stone masonry, quarrying, brickmaking and fracking. Exposures can cause the lung-scarring disease silicosis, lung cancer and other chronic health problems.
Discussions convened by the Institution of Occupational Safety and Health (IOSH) last year have resulted in the new pact. Representatives from the UK’s Health and Safety Executive (HSE), the Office of Road and Rail (ORR), Crossrail Ltd, the Mineral Products Association and Unite are among those to have joined IOSH in signing the commitment.
Signatories have agreed to work together to reduce exposure to RCS through effective monitoring and management of dust. They also say they will increase awareness and understanding of the potential health risks associated with exposure to RCS in order to change attitudes and behaviours and share good practice on the management of RCS across industry sectors.
In the commitment, the organisations state that it is “an agreed plan of action that will pool the knowledge and resources of some of the leading organisations involved in managing the risks of RCS”.
According to Imperial College London research, around 800 people in Britain a year die from lung cancer caused by prolonged RCS exposure at work, with 900 new cases being diagnosed annually.
In the commitment, Unite national safety officer Bud Hudspith notes: “Silica dust kills thousands of workers every year – Unite is committed to improving controls on silica and challenging employers and regulators at every level to achieve this. Where relevant, we expect to see explicit commitments in tender documents on the control of silica dust.”
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.
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.”