Occupational cancer – is this still a concern for workers and employers?
By Dr Lesley Rushton, Emeritus Reader in Occupational Epidemiology at Imperial College London
Your work environment should not put you at risk of disease or injury, yet many thousands of workers worldwide are potentially exposed to hazardous substances at work every day.
We carried out a study in Britain in 2012 which estimated how many of the cancers occurring each year could be caused by previous exposure to cancer causing substances (carcinogens) at work.
The study aimed to identify the main carcinogens, occupations and industry sectors, and to forecast how many cancers would occur in the future if nothing changed, and how these could be reduced if a range of different interventions were used.
What did the study find?
We found that just over 5% of all cancers were estimated to be due to past occupational exposures, resulting in more than 8,000 deaths and nearly 13,600 new cases a year. This compares with about 200 deaths a year due to workplace injuries.
A higher proportion of cancers in men were caused by work (8%) compared with women (2%). This was mainly due to high exposures experienced by men in the past in heavy manufacturing sectors and industries such as mining and the dominance of men in the construction industry.
What were the types of cancer most associated with occupation and what caused them?
Almost all mesotheliomas (95%) were estimated to be caused by work, with 14% of lung cancers and around 5% of female breast cancers, non-melanoma skin cancers and bladder cancers due to exposure to carcinogens at work.
The major causes were exposure to asbestos (mesothelioma and lung cancer), night shift work (breast cancer), mineral oils (lung, bladder and skin cancers), solar radiation (skin cancer), silica (lung cancer), diesel engine exhaust emissions (DEEE) (lung and bladder cancers), coal tars and pitches (lung and skin cancers) and occupation as a painter (bladder and lung cancers, non-Hodgkin lymphoma, soft tissue sarcoma) or welder (lung cancer).
Which industries are most affected?
Just over half of the total cancers in men occurred in the construction industry.
Similarly, more than half of the total cancers in women were due to shift (night) work (see graph below).
However, a considerable number of cancers also occurred to workers in the manufacturing and service industries, particularly in mining, transport, retail and hospitality, public administration/defence, and farming.
Asbestos and silica
Asbestos exposure was shown to cause nearly 2,000 mesotheliomas and over 2,000 lung cancers. Over half of these occurred in the construction industry. Out of the 900 lung cancers, 700 were caused by exposure to silica dust in the construction industry.
What will happen in the future?
Many occupational cancers take a long time to develop and often occur after retirement.
Our study also showed that unless measures are taken to reduce carcinogenic exposures at work, these cancers will continue to occur at the same rate every year.
Using silica exposure as an example, we demonstrated that not only is it important to think about reducing statutory workplace limits, (Work Exposure Limits (WEL)) but that considerable reduction in occupational cancers could be achieved by improving the compliance to limits already in place. Particular encouragement is needed for small companies and self-employed workers.
Asbestos will also be an important occupational risk factor in the future. Although it is no longer used in the construction of buildings, it can still be a risk for workers today during demolition and maintenance. The number of asbestos-related cancers will continue to rise in the future, if steps aren’t taken to reduce exposure.
How can we reduce the risks from asbestos and silica?
Many workers are unaware of situations where asbestos might be present.
When working on older buildings, a survey should always be carried out to locate and record where asbestos might be present, and an appropriate plan should be developed to decide how to deal with it.
Where it is necessary to make extensive repairs to asbestos-containing materials or remove them from a building, it is strongly advised to have the work carried out by a specialist contractor. An assessment of risks to workers needs to be carried out and workers, including contractors, need to be told about health risks and how to keep themselves safe.
Silica dust exposure occurs through processes such as cutting, grinding and polishing of silica-containing stone, rocks, sand and clay, as well as products such as bricks, tiles, concrete and some plastic composites.
It is imperative that workers’ exposure to silica dust is prevented when working on or nearby silica-containing materials. Measures such as water suppression of dust, improved ventilation, regular maintenance of machinery, and use of appropriate personal protective equipment where necessary have all been shown to be effective in reducing exposure to silica.
For more information and to download free resources on how to manage carcinogens such as asbestos and silica dust at work, visit the IOSH No Time to Lose campaign website – www.notimetose.org.uk.