NHS Barking and Dagenham Briefing on disease linked to Asbestos in Barking & Dagenham

Transcription

1 APPENDIX 1 NHS Barking and Dagenham Briefing on disease linked to Asbestos in Barking & Dagenham 1. Background 1.1. Asbestos Asbestos is a general name given to several naturally occurring fibrous minerals that have crystallised to form long thin fibres. Asbestos minerals are common in the environment and may be found in soil due to erosion of asbestos-bearing rock. Asbestos fibres are strong, heat and chemical resistant and they do not evaporate into the air or dissolve in water. Such properties made it an ideal material for use in a number of industrial and building products. However due to the health risks of exposure to asbestos, importation, supply and use of all asbestos products have been banned in the UK since People may still be exposed to existing asbestos-containing materials in buildings because its use was so widespread use in the past Health The health effects of asbestos on humans have been known about for a number of years, and a causal link between asbestos and mesothelioma was first reported in Exposure to inhaled asbestos fibre is linked to three main illnesses : Asbestosis which may be pleural asbestosis or parenchymal asbestosis. o Pleural asbestosis occurs when inhalation of asbestos causes irreversible lung fibrosis and the build up of plaques in the pleura (or lining) of the lungs. Pleural plaques may be observed in between 20% and 60% of individuals occupationally exposed to asbestos. o Parenchymal asbestosis is also due to the presence of asbestos fibres in the lung, which causes fibrosing of the lung structure. Clinical symptoms of asbestosis can take up to thirty years to develop after someone is first exposed to asbestos, although it may be possible to see changes on X-ray before then. The main symptoms are shortness of breath, cough and enlargement of the heart. Mesothelioma is a rare malignant tumour of the pleura (lung lining) or peritoneum (abdominal lining). As with asbestosis, mesothelioma has a long period between being exposed to asbestos and falling ill. This is usually at least ten years but in most cases it is approximately 30 years, although exposure to greater quantities may shorten the time frame. Bronchial carcinoma or lung cancer - Exposure to asbestos fibres may cause all four major types of lung cancer, namely squamous cell

2 carcinoma, adenocarcinoma, large-cell carcinoma and small-cell carcinoma. These vary in malignancy. A latency period of approximately 30 years or more may occur between the time of initial exposure and a tumour developing. As can be seen from the graph below, although asbestos use was banned in 1999 there will continue to be an increase in the number of people being diagnosed with asbestos related illnesses, because of the time it takes for the disease to become apparent, which can be 20 to 40 years or more. HSE asbestos-related deaths & disablement benefits in GB Link to Smoking Asbestos has been recognised as an important risk factor for lung cancer for many years, but although lung cancer death statistics for Great Britain are available, the number of deaths attributable to asbestos cannot be determined directly. This is because there are a number of agents that can also cause the disease - most importantly, tobacco smoke - and lung cancers resulting from asbestos exposure are clinically indistinguishable from those caused by these other agents. Although asbestosis is non-malignant, its occurrence increases the risk of lung cancer, especially in smokers. Both asbestos and smoking will on their own increase the incidence of lung cancer, but together they act in a synergistic manner, whereas the risk of mesothelioma appears to be independent of smoking. According to one authority on the disease, Dr John Moore-Gillon, a 20-a-day smoker has a risk of lung cancer about 15 times greater than that of a lifelong non-smoker. In addition if they have had asbestos exposure sufficient to cause asbestosis, this risk is multiplied fivefold, so they are about 75 times more likely

3 to get lung cancer than a non-smoking non-asbestos exposed individuals( Asbestos related diseases published 1997) Industry Because asbestos fibres do not dissolve in water or evaporate, and are resistant to heat, fire, chemical and biological degradation this has made it an ideal material for use in a number of products. These include insulation material for buildings, boilers & pipes, sprayed coating/lagging, insulating boards, asbestos cement, ropes, cloth, car brakes & clutches, ceiling & floor tiles, coated metal, textured paints & reinforced plastic amongst others. To assess occupational risk the proportional mortality rate or PMR is calculated by looking at all deaths from a condition, in this instance mesothelioma, and breaking it down further by age and occupation. If the PMR is greater or less than 100, this indicates that the observed number of mesotheliomas is greater or less than the average for all occupations. As can be seen on the tables in Appendix A, for men the occupations with the highest proportional mortality rates between 1980 and 2000 were metal plate workers, vehicle body builders and plumbers and gas fitters. The occupations with the highest risk for females were metal plate workers, chemical workers and labourers / foremen. A geographical analysis of deaths shows that those areas which had large shipbuilding industries such as Barrow-in-Furness, North Tyneside, Plymouth and Medway experienced higher than expected death rates from mesothelioma amongst men (Appendix B). Industries most commonly associated with exposure to asbestos include the asbestos processing industry, ship building and dock areas and vehicle manufacturing (specifically the manufacturing of brake linings). All these industries existed in Barking and Dagenham during the last half of the 20 th century. Importation and therefore use of asbestos into Britain peaked between 1955 and 1965, while at the same time industries were not subject to the same rigorous health and safety and environmental legislation as exists now.

4 2. Asbestos related disease in Barking & Dagenham The tables in Appendix B show that the standardised mortality rate (SMR) from mesothelioma between 1981 and 2005 was highest for women in Barking and Dagenham than for women anywhere else in Great Britain. The SMR is the ratio of observed deaths to expected deaths from a specific condition, so the SMR of the standard population (in this case Great Britain) is 100. Meanwhile the SMR for men in Barking & Dagenham was the 9 th highest in the country. An earlier investigation into mesothelioma deaths in 2003 also concluded that the SMRs for mesothelioma for all wards in the Borough were considerably elevated although this was not broken down by gender. However while the elevated SMR is concerning, it should be remembered that there may be a number of explanations. The number of deaths over the 25 year period, while undoubtedly upsetting for relatives and friends, is relatively small when looking at the number of deaths from all causes that there have been during that time. The deaths of 60 women were attributed to mesothelioma during that time but as the table below shows both the number of deaths and the SMR has decreased consistently over time. Mesothelioma SMRs for females in Barking & Dagenham by 5 year time period (HSE 2008) Deaths SMR Deaths SMR Deaths SMR Deaths SMR Deaths SMR Barking & Dagenham Support for people with asbestos related disease People with asbestos related disease will benefit from any investment in services for people with chronic lung disease. This includes the British Lung Foundation s current initiative in Barking & Dagenham to raise awareness of chronic lung disease and ensure people seek early treatment. There has also been recent investment in local GP services to encourage GPs to screen patients for signs of early lung disease. And there has been significant investment in recent years in End of Life (palliative) Care. Within Barking & Dagenham there has also been some specific investment in support for people with asbestos related disease. In 2008/9 the local Asbestos Support Group received funding of 10,000 from NHS Barking & Dagenham to establish a support group. 4. Discussion Because of the existence of industries with known links to asbestos related disease in the 20 th century in Barking and Dagenham, mortality from asbestos related diseases would be expected to be higher than the national average. However it appears to be higher than anywhere else in the country for women. There may be several possible explanations as to why this is the case:

5 4.1. There was a concentration of asbestos using industries in Barking & Dagenham during the second half of the twentieth century, before importation of asbestos was prohibited. These include Cape Asbestos, shipbuilding, docks and Ford Cars. This concentration of the specific industries may have been greater here than elsewhere in the UK It has been suggested that Cape Asbestos were mainly involved in the processing of crocidolite or blue asbestos which is considered to be more dangerous to health than white asbestos (chrysotile). The majority of cases of mesothelioma are linked to blue asbestos, or less frequently to brown asbestos (amosite). Chrysotile is seldom linked to mesothelioma Robustness of data because of the very small numbers involved the data may not be robust. Small numbers in an epidemiological study give rise to very wide confidence intervals. In this case an SMR of 501 has a confidence interval of between 382 and 644, so while one can be fairly sure that the risk of women dying with mesothelioma is higher than the Great Britain average, it might not be the highest in the country, and the apparent result could occur because of chance or bias Health and safety and environmental legislation today would ensure that risks were cut to a minimum to avoid risk to people both inside and outside the workplace. If uniforms and work clothes are not laundered at work, then family members of people working with asbestos may be at risk of asbestos-related disease as fibres can be carried home on clothing. So too can the people involved in laundering the clothes, either at home or in industrial laundries. In both instances because of historical work patterns this issue is more likely to affect women than men Because of the long latent period between exposure to asbestos and disease occurring which can be up to 40 years, more information is needed about patterns of migration drawing comparisons between Barking & Dagenham and other industrialised areas. For example are older people more likely to stay or move away from various industrialised areas when they retire? More information is also needed about the working pattern of women locally and whether this differed from other places in the UK, specifically during 1940 to 1960 when it appears the greatest exposures may have occurred. 5. Acknowledgements This report has been compiled using a variety of information sources including the Health Protection Agency, the Health & Safety Executive and the Office of National Statistics. Linda Bailey October 2009 Consultant in Public Health

6 APPENDIX A Highest risk occupations linked to asbestos for males in Great Britain in (HSE) Highest and lowest risk occupations linked to asbestos for females in Great Britain in (HSE)

7 APPENDIX B HSE Great Britain SMR for Mesothelioma in Females (2008) HSE Great Britain SMR for Mesothelioma in Males (2008)