Lung Disease and Work

The Lane Lecture is an annual event hosted by the Centre for Occupational and Environmental Health at the University of Manchester. Named in honour of Ronald Lane, the first ever Professor of Occupational Health at the University.

This year the lecture was delivered by Professor David Fishwick, Chief Medical Officer and Co-Director of the Centre for Workplace Health. His talk was entitled The lungs at work: from cotton mills to composites? One of the key messages is that diseases such as byssinosis and silicosis are not historic issues.

In 1890 there were more cotton mills in Manchester than in the rest of the world. But that is no longer the case – the industry has been transferred overseas, particularly to developing economies. So byssinosis, which is caused by exposure to cotton dust, is no longer a problem in the UK. However, it’s a different matter in those countries where cotton is now produced.

Studies carried out in recent years have shown high incidences of byssinosis in some mills in developing countries. One study in Karachi, Pakistan in 2008 found that among 362 textile workers 35.6% had byssinosis. (Prevalence of Byssinosis in Spinning and Textile Workers of Karachi, Pakistan, Archives of Environmental & Occupational Health, Vol. 63, No. 3, 2008 )

Professor Fishwick also focused on Silicosis, the oldest known occupational lung disease which remains a significant problem across the globe, including the UK. This debilitating disease is caused by exposure to respirable crystalline silica (particles smaller than 10 microns) which can occur in many industries, including mining, quarrying, brick and tile manufacture, stone masonry, glass manufacture, tunnelling, foundries, ceramic manufacturing and construction activities.

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The risk is clearly associated with the level of exposure and it only takes a regular exposure to very low concentrations to cause the disease. The US Occupational Safety and Health Administration (OSHA) estimates that 30% of workers with 45 years of exposure to 0.1 mg/m3 respirable crystalline silica dust will develop silicosis (see page 16394 of the “Final Rule”). Yet 0.1mg/m3 (respirable dust) is the current Workplace Exposure Limit for crystalline silica in the UK.

Clearly the current WEL is not a “safe level” and there is a very strong case for reducing it. In the US OSHA has recently announced a reduction in their Permitted Exposure Limit for silica down to 0.05 mg/m3. No change is proposed in the UK. The HSE’s view is that there are difficulties accurately measuring exposures lower than 0.1mg/m3, so it would be difficult to demonstrate compliance, and that, in any case, employers have a duty to not only meet the exposure limit but the apply “principles of good control practice” set out in Schedule 2A of the Control of Substances Hazardous to Health Regulations. Not everyone agrees with them, however.

As well as causing silicosis, respirable crystalline silica is a carcinogen. It’s estimated that in the UK it causes around 600 deaths per year from lung cancer shows  with 450 of these occurring from exposures in the construction sector.

Occupational cancer deaths by cause in Great Britain, 2005 (HSE)

Personally, I’d like to see the WEL reduced and research done to develop better sampling methods which will allow low levels of exposure to be evaluated. I do sympathise, though, with their emphasis on control. Reducing exposure by introducing improved controls is the key to preventing workers from developing industrial disease. Measurement can help us to understand exposure and identify where improved controls are needed. But sometimes the problem is obvious and in those cases it’s better to spend time, effort and money sorting it out, particularly when there are well established solutions available.

Health in Construction

A couple of weeks ago I travelled down to Birmngham to give a talk on behalf of the BOHS Breathe Freely initiative at the Health and Wellbeing event at the NEC. The Title of the talk was Managing Health in Construction – What Good Looks Like. An annotated version of the slides I used during the talk are now available on Slideshare

To prepare for the talk I did a little research on the meaures that are readily available to control exposure to contaminants, particularly dust, during common activities on construction sites. A number of studies have been done, both on-site and in the laboratory to assess the effectiveness of water supression and on-tool extraction for power tools. These studies have confirmed just how they can be.

For example

  • A large scale study in Ireland by Healy et al showed that the use of local extraction built into on-tool shrouds could reduce dust exposures by up to 99%
  • Laboratory tests by Thorpe et al showed water suppression on cut-off saws reduced dust levels by up to 99%

Despite this, in a large proportion of cases these engineering controls are not being used with reliance placed on respiratory protection which is often incorrectly used and inadequately managed. So one of the main aims of the BOHS Breathe Freely initiative is to raise awareness of the types of controls that can be used to reduce exposure. Hopefully in the not too distant future we’ll see water supression and on-tool extraction become the norm rather than the exception.

 

References

Measurements of the E€ectiveness of Dust Control on Cut-off€ Saws Used in the Construction Industry. Thorpe et al. Ann Occup Hyg Vol. 43, No. 7, pp. 443-456, 1999

An Evaluation of On-Tool Shrouds for Controlling Respirable Crystalline Silica in Restoration Stone Work.  Healy et al. Ann Occup Hyg 2014;58:1155-1167

Silica exposure in the construction industry

One of the most important health risks encountered by construction workers is exposure to respirable crystalline silica dust. Crystalline silica, mainly in the form of quartz, is the main component of most rocks, sands and clays. In the construction industry it can be found in  stone, concrete, aggregates, mortars and other materials.

Respirable particles (smaller than 10 microns in diameter) of crystalline silica,  which are produced during many common activities such as cutting, blasting or drilling granite, sandstone, slate, brick or concrete, penetrate deep down into the lungs where they can cause serious damage. Regular, repeated exposure to respirable crystalline silica can lead to silicosis, a debilitating lung disease, chronic obstructive pulmonary disorders (COPD) and lung cancer. It usually takes many years of exposure to silica dust before these symptoms start.

A couple of weeks ago I was giving a talk to a meeting of safety consultants on the BOHS breathefreely initative and decided to include some discussion on silica exposures in the industry. Unfortunatly no major study has been carried out in the UK. However, there are several detailed papers on exposures in the industry in some comparable countries in the Annals of Occupational Hygiene and other journals, so I was able to include some figures in my talk.

The research has shown that many of the common activities undertaken in the construction industy lead to exposures well in excess of the UK Workplace Exposure Linit of 0.1 mg/m3 for respirable silica – and this isn’t a “safe limit” with an estimated 2.5% of workers exposed to this concentration for only 15 years developing silicosis. Yet for most of the common operations where workers are at risk from exposure to silica, there are control measures available that are usually relatively straight forward to implement.

IOHA 2015

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A couple of weeks ago I was in London attending the 10th International Scientific Conference of the International Occupational Hygiene Association (IOHA) organised by the British Occupational Hygiene Society (BOHS). The conference was held in lieu of he usual annual BOHS Conference that normally takes place that time of the year. It was a step upwards with double the number of delegates who came to London from all parts of the world. It was a packed programme with sessions starting most days at 8 a.m. and not finishing until well after 6 p.m. The organisers also managed to schedule in three technical tours – behind the scenes at the National History Museum, the London Tube and Tower Bridge -which proved to be very popular.

With parallel sessions taking place for most of the conference it was impossible to see everything. But sessions I attended and enjoyed included the workshop on noise control, the sessions on risk communication, construction, career development, the presentation by the IOHA award winner, Noel Tressidor (he only occupational hygienists to tour with the Beatles!), and the highly entertaining (as usual!) Ignite session.

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Highlights for me included the Keynote presentations by Professor Paul Dolan and Professor Sir David Spiegelhalter, who were both, in different ways, very entertaining and brought us different, non-occupational hygiene, perspectives. They made me think about how some of the concepts and ideas they told us about could be applied to the practice of preventing ill-health at work. That isn’t to say that the other keynote speakers from fields more closely linked to occupational hygiene weren’t good! They were all of a high standard and brought us up to date on some key issues in toxicology, risk communication and risk management in practice. Similarly the scientific sessions and workshops allowed delegates to hear about some important developments in the field and discuss ideas on how to take the science and practice of occupational hygiene forward in the 21st Century. But I think it is also important to look beyond the boundaries of our own domain. We can learn from psychologists, economists, experts in communication and others to give us new ideas and help us to develop fresh approaches.

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On the Tuesday night the BOHS also launched their initiative aimed at increasing awareness and reducing respiratory disease in the construction industry and to tie in with that there was an excellent Keynote by Steve Hails, the Director of heath and safety for the Crossrail project.

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Although learning from the formal sessions is important, so are the informal discussions that take place outside during the breaks, mealtimes and socials and other “free time”. Conferences are a great opportunity for networking – to meet old friends and make new connections.

The social side of the conference was excellent too. With receptions hosted by sponsors on both the Monday and Tuesday evenings. Plus the Monopoly themed Conference Dinner on the Wednesday – with a fun casino, photo booth and karaoke band to prove that occupational hygienists can relax and enjoy themselves too!

It was an educational, enjoyable but exhausting four days. It took me several days to recover!

All photographs are by Teresa O’Neill Photography

Dark Satanic Mills

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Many people when they get to a certain age start to wonder where they came from. That was certainly true for me so a few years ago I started to research my family tree. Although there were a few surprises my research confirmed that I my family were ordinary workers. I wanted to find out about my roots, about my ancestors, where they came from and how they lived. And as an occupational hygienist I couldn’t help but be interested in what they did for a living and their working conditions.

Halifax Mill Chimneys

Coming from Lancashire it wasn’t a surprise to find that many of my ancestors who lived in the 19th and 20th Centuries were employed at some time during their lives in cotton mills. And working in cotton mills they were faced with a whole host of health risks.

I’ve always been interested in industry and when I was a boy my mother arranged for me to have a look round the mill where she worked. The first thing that hit me when I walked in the mill was the tremendous noise. Levels in weaving sheds were likely to be well above 90 dBA – often approaching, or even exceeding 100 dB(A). Communication was difficult and mill workers soon learned how to lip read and communicating with each other by “mee mawing” – a combination of exaggerated lip movements and miming

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Not surprisingly many cotton workers developed noise induced hearing loss – one study in 1927 suggested that at least 27% of cotton workers in Lancashire suffered some degree of deafness. Personally, I think that’s an underestimation. This is how the term “cloth ears” entered the language – it was well known that workers in the mills were hard of hearing.

This lady is a weaver and is kissing the shuttle – sucking the thread through to load the shuttle ready for weaving.

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This practice presented a number of health risks – the transmission of infectious diseases, such as TB, but as the shuttle would be contaminated with oil, and the oils used then were unrefined mineral oil – there was a risk of developing cancer of the mouth.

Exposure to oil occurred in other ways particularly for workers who had direct contact with machinery or where splashing of oil could occur. There was a high incidence of scrotal cancer in men who operated mule spinners – and this was a problem even in the 1920s. In earlier times workers in mills had to work in bare feet as the irons on their clogs could create sparks which could initiate a fire due to the floorboards being soaked with oil. Contact with these very oil soaked floorboards led to cases of foot cancer.

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And of course there was the dust. Exposure to cotton dust, particularly during early stages of production, can lead to the development of byssinosis – a debilitating respiratory disease. An allergic condition, it was often known as “Monday fever” as symptoms were worst on Mondays, easing off during the week. A study on 1909 reported that around 75% of mill workers suffered from respiratory disease.

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The worst areas for dust exposures were the carding rooms where the cotton was prepared ready for spinning, but dust levels could be high in spinning rooms too.

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Although control measures started to be introduced in the 1920’s workers continued to be exposed to dust levels that could cause byssinosis. Studies in the 1950’s showed  than more than 60% of card room workers developed the disease as well as around 10 to 20% of workers in some spinning rooms.

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A lot of work was devoted to studying dust levels, developing standards and control measures by the early pioneers of occupational hygiene in the UK and I’m sure this contributed to improved conditions in the cotton industry in the UK. I’m not sure I’d like to have to operate their dust sampling kit though – it certainly wasn’t personal sampling!

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Today things are different. The carding machines, spinning frames and looms are silent and have been sent for scrap. The mills have been abandoned and are derelict or demolished or have been converted for other uses.

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Cotton is still in demand but it’s a competitive market and the work has been moved to other countries where labour is cheap and standards are not as high – Africa, China and the Indian sub-continent. Another consequence of globalisation. Although you could say that the industry is returning to where it originated in the days before the industrial revolution. Sadly, conditions and working methods in many workplaces in the developing world are primitive and controls are minimal. It seems like the lessons learned in the 20th Century in the traditional economies are rarely applied so not surprisingly those traditional diseases associated with the industry are re-emerging in developing economies.

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Studies carried out in recent years have shown high incidences of byssinosis in some mills developing countries. One study in Karachi, Pakistan in 2008 found that among 362 textile workers 35.6% had byssinosis. (Prevalence of Byssinosis in Spinning and Textile Workers of Karachi, Pakistan, Archives of Environmental & Occupational Health, Vol. 63, No. 3, 2008 ). A study of textile workers in Ethiopia published in 2010 showed a similar proportion – 38% had developed byssinosis,  with 84.6% of workers in the carding section suffering from the disease

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Another study, this time into textile workers’ noise exposures in Pakistan indicated noise levels in the range 88.4-104 dB(A). 57% were unaware that noise caused hearing damage and almost 50% didn’t wear ear defenders

William Blake wrote of “Dark Satanic Mills” in 1804. This was still a fair description of the working conditions in Lancashire when my ancestors worked in the mills. And I believe its valid today in many workplaces in the developing world.

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It’s not easy to get accurate figures on occupational health in the UK and so much more difficult in the developing world. The best estimate we have (and it’s likely to be an underestimate) is that 2.3 million people die due to accidents at work and work related disease (World health Organisation). And the vast majority of these are due to ill health

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Some occupational hygienists might take a dispassionate, academic interests in dust exposure. But I think most of us are motivated by a genuine desire to prevent ill health at work and improve working conditions. Many of us work in countries where conditions although far from perfect are relatively good. But can we turn a blind eye to what’s happening in the rest of the world?

Personally, I think it’s something we need to be thinking about.

Vital statistics

On 2 July the Health and Safety Executive (HSE) released their provisional data on the numbers of workers killed in accidents at work. They revealed that 133 workers were fatally injured in the period between April 2013 and March 2014 compared with 150 in the previous year. This continues the trend in a reduction in the number of fatalities in recent years.

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(source: http://www.hse.gov.uk/statistics/fatals.htm accessed 14 July 2014)

The figures on deaths from mesothelioma were also published on 2 July. These showed that there were 2 535 deaths from this disease in 2012, continuing the increasing trend.

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(Source: http://www.hse.gov.uk/statistics/causdis/mesothelioma/index.htm accessed 14 July 2014)

The latest statistics on deaths from ill health, other than mesothelioma, are not available at the time of writing. However, HSE estimates that around 13 000 deaths each year are attributable to occupational disease – primarily respiratory diseases and occupational cancers, arising from exposure to dusts, fumes, chemicals and work circumstances. If anything, this is an underestimate – many suspected sources of work-related disease have not been fully evaluated.

The reduction in deaths from accidents at work are to be welcomed. The reasons are complex and reflect a number of factors, including the efforts of employers to manage safety risks and good work by the HSE. However, the situation on occupational ill health remains of great concern. Deaths from occupational diseases far outnumber those from accidents at work by a ratio of more than 80 to 1. It’s a situation that really can’t be allowed to continue.

Most occupational disease can be prevented by applying occupational hygiene principles. So why doesn’t this happen? There are many reasons but one important factor is that accidents happen now and have an immediate effect on business. Ill health is long term and the consequences don’t occur until many years after exposure and don’t impact on short term profitability. But there’s a knowledge gap too – lack of recognition that there’s a problem due to poor understanding of health issues and limited understanding of good control practice for chemical hazards.

Occupational hygienists have the knowledge and skills to identify, assess health risks in the workplace, design control measures and develop control strategies. Action by employers and the HSE is urgently needed to prevent and control exposures at work to those agents that can cause occupational ill-health. To do that they’re going to need the support from competent professional occupational hygienists.

Silica exposure in construction

On Monday this week the Health and Safety Executive (HSE) announced that they were launching a two-week inspection blitz focusing on poor conditions likely to lead to ill health on construction sites, a sector in which occupational hygiene controls have, for too long, been overlooked. Last year there were 39 fatal injuries to workers in the construction sector. However, it’s estimated that there are about 100 deaths from occupational disease for every fatal accident in the construction. The HSE have said that their inspectors will be looking in particular at respiratory risks from dusts including silica materials; exposure to other hazardous substances such as cement and lead paint; manual handling, noise and vibration.

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A particular risk in construction work is exposure to crystaline silica dust which is present in materials including stone, concrete, aggregates, mortars and other materials. Respirable particles (smaller than 10 microns in diameter and can reach the deepest regions of the lung) of crystalline silica,  which is produced during many common activities such as cutting, blasting or drilling granite, sandstone, slate, brick or concrete, penetrate deep down into the lungs where they can cause serious damage.

Regular, repeated exposure to respirable crystalline silica can lead to silicosis, a debilitating lung disease, chronic obstructive pulmonary disorders (COPD) and lung cancer. It usually takes many years of exposure to silica dust before these symptoms start.

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Risk of silicosis – Source: HSL 

Most people who develop silicosis  or lung cancer will have been exposed to low amounts of silica dust for 20 years or more without being aware anything was wrong. Unlike safety hazards where the effects are short term, health hazards are often ignored as the symptoms only appear many years after exposure.

Over 500 construction workers are believed to die from exposure to silica dust every year, yet research carried out on behalf of the HSE suggests that employers underestimate worker exposure to silica in the construction industry.

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Yet for most of the common operations where workers are at risk from exposure to silica, there are control measures available that are usually relatively straight forward to implement.

One common task is the cutting of concrete or stone using an angle grinder where extremely high dust concentrations can be generated. Sometimes it’s possible to eliminate the risk entirely by using alternative materials such as plastic kerb stones.  they’re lighter than stone or concrete, they also have other health benefits by reducing musculoskeletal injuries associated with manual handling.

In cases where substitution isn’t possible, using water suppression techniques can be very effective in reducing dust generation at source.

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Fitting on-tool extraction onto power tools can also be effective. Research carried out by HSE has shown that a well designed system can reduce exposure by as much as 40%.

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Exposure to silica dust can be prevented or controlled if employers recognise the risk and are willing to do something about it. Hopefully the HSE’s “blitz” on construction sites will help to raise awareness and lead to action by employers to address these serious health risks.