By John Cherrie
Each year there are 1,800 people killed on the roads in Britain, but over the same period there are around four times as many deaths from cancers that were caused by hazardous agents at work, and many more cases of occupational cancer where the person is cured. There are similar statistics on workplace cancer from most countries; this is a global problem. Occupational cancer accounts for 5 percent of all cancer deaths in Britain, and around one in seven cases of lung cancer in men are attributable to asbestos, diesel engine exhaust, crystalline silica dust or one of 18 other carcinogens found in the workplace. All of these deaths could have been prevented, and in the future we can stop this unnecessary death toll if we take the right action now.
In 2009, I set out some simple steps to reduce occupational exposure to chemical carcinogens. The basis was the recognition that the overwhelming majority of workplace cancers from dusts, gases and vapours are caused by exposure to just ten agents or work circumstances, such as welding and painting (see chart). Focusing our efforts on this relatively short priority list could have a major impact.
Many of these exposures are associated with the construction industry. Almost all are generated as part of a process and are not being manufactured for industrial or consumer uses, e.g. diesel engine exhaust and the dust from construction materials that contain sand (crystalline silica).
The strategies to control exposure to these agents are well understood and so there is no need to invent new technological solutions for this problem. Use of containment, localized ventilation targeted at the source of exposure and other engineering methods can be used to reduce the exposures. If further control is needed then workers can wear personal protective devices, such as respirators, to filter out contaminants before they enter the body.
There are also robust regulations to ensure employers understand their obligations to employees, contractors and members of the public, both in Britain through the Control of Substances Hazardous to Health (COSHH) Regulations and in the rest of Europe via the Carcinogens and Mutagens Directive.
We know that as time goes on, most exposures in the workplace are decreasing by between about 5% and 10% each year. This seems to be true for many dusts, fibres, gases and vapours, and it is a worldwide trend. There is every reason to believe this is also true for the carcinogenic exposures we are discussing. This means that over a ten-year period the risk of future cancer deaths is may drop by about half. If we could increase the rate of decrease in exposure to 20% per annum then after 10 years the risk of future disease should have decreased by about 90%.
However, during the five years since my article was published, very little has been done to improve controls for carcinogens at work. Recent evidence from the Health and Safety Executive (HSE), the regulator in Britain, shows widespread non-compliance at worksites where there is exposure to respirable crystalline silica. Most people are still unaware of the cancer risks associated with being a painter or a welder and so no effective controls are generally put in place. There have been no effective steps taken to reduce exposure to diesel engine exhaust, or most of the other “top ten” workplace carcinogens. What is the barrier preventing change?
In my opinion, the main issue is that we don’t perceive most of these agents or situations as likely to cause cancer. For example, airborne dust on construction sites, which often contains crystalline silica and may contain other carcinogenic substances, is considered the norm. Diesel soot is ubiquitous in our cities and we all accept it even though it is categorized as a human carcinogen. In my paper I complained that there were ‘no steps taken to reduce the risk from diesel exhaust particulate emission for most exposed groups and no particular priority given to this by regulatory authorities.’ Nothing has changed in this respect. We need an agreed commitment from regulators, employers and workers to change for the better. Perhaps we need to consider requiring traffic wardens to wear facemasks and encourage painters to work in safer healthier ways. At least we should take a fresh look at what can reasonably be done to protect people.
We know that since 2008 the number of road traffic deaths in the United Kingdom has decreased by about a third and downward time trend seems relentless. Road traffic campaigners have envisaged a future of zero harm from motor vehicles. Similarly we know that the level of exposure to most workplace carcinogenic substances is decreasing. Can we not also consider a future world where we have eliminated occupational cancer or at least reduced the health consequences to a tiny fraction of today’s death toll? It will be a future that our children or their children will inhabit because of the long lag between exposure to the carcinogens and the development of the disease, but unless we act the danger is that we never see an end to the problem.
As a first step we need to have an effective campaign to raise awareness of the problem of workplace cancers and to start to change attitudes to the most pernicious workplace carcinogens.
John Cherrie is Research Director at the Institute of Occupational Medicine (IOM) in Edinburgh, UK, and Honorary Professor at the University of Aberdeen. He has been involved in several studies to estimate the health impact from carcinogens in the workplace. He is currently Principal Investigator for a study that will estimate the occupational cancer and chronic non-malignant respiratory disease burden in the constructions sector in Singapore. In 2014 he was awarded the Bedford Medal for outstanding contributions to the discipline of occupational hygiene. He is the author of the paper ‘Reducing occupational exposure to chemical carcinogens‘, which is published in the journal Occupational Medicine.
Occupational Medicine is an international peer-reviewed journal, providing vital information for the promotion of workplace health and safety. Topics covered include work-related injury and illness, accident and illness prevention, health promotion, occupational disease, health education, the establishment and implementation of health and safety standards, monitoring of the work environment, and the management of recognised hazards.
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