PatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
The risk of asbestos-related lung disease increases with the duration and degree of exposure and also depends on the type of asbestos fibre. People exposed to asbestos often develop lung disease after a long latent period.  Asbestos exposure may cause:
- Benign disease: pleural plaques, pleural thickening, benign pleural effusions
- Interstitial lung disease: asbestosis
- Malignant disease: particularly mesothelioma and lung cancer
The three main types of asbestos that have been used commercially are crocidolite (blue asbestos), amosite (brown) and chrysotile (white). All fibre types are dangerous. There was discussion in the literature that blue and brown asbestos were more dangerous than white. There is, however, sufficient evidence to suggest that chrysotile can be as carcinogenic as the other types.
Alveolar macrophages play a significant role in the aetiology of asbestosis-related diseases.
- High-risk populations include construction trades, joiners, plumbers, electricians, painters, boilermakers, shipyard workers, railroad workers, asbestos miners and Navy veterans.
- The annual number of mesothelioma deaths in the UK is increasing, with 2,347deaths in 2010 compared with 153 in 1968.
- The expected number of deaths amongst males is predicted to increase to a peak of 2,038 in the year 2016.
- The World Health Organization (WHO) has estimated that 107,000 people worldwide die each year from mesothelioma, lung cancer, and asbestosis. Mesothelioma is still increasing in most European countries and in Japan but has peaked in the USA and Sweden.
- The incidence of asbestos-related disease will continue to increase in developing countries because of the continued unregulated use of asbestos.
- Exposure to cigarette smoke increases the risk of developing lung cancer in patients with a history of asbestos exposure.
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- Some patients are entitled to compensation and should seek advice from the Department for Work and Pensions (see link under 'Further reading & references', below) or dedicated charity organisations.
- Smoking cessation is important because smoking increases the risk of developing lung malignancy.
- Influenza immunisation and pneumococcal immunisation should be given to patients with asbestosis or lung malignancy.
- Pleural plaques usually affect the parietal pleura (especially adjacent to the sixth to ninth ribs and along the surface of the diaphragm) and they occur in 20-60% of people who have been exposed to asbestos.
- Pleural plaques are usually asymptomatic but may cause chest pain. They remain benign and do not become malignant although there is some evidence that they may be an independent risk factor for mesothelioma. There is some evidence that they may be associated with a restrictive pattern on lung function tests but this is not thought to be clinically relevant.
- CT scan is more sensitive than a CXR and distinguishes pleural plaques from solid tumours.
Diffuse pleural thickening
- Diffuse thickening of the pleura may occur after exposure to asbestos; however, other causes include previous haemothorax, tuberculosis, chest surgery, radiation, infection and exposure to drugs such as methysergide. It is therefore less specific to asbestos exposure than pleural plaques.
- Extensive diffuse pleural thickening may cause breathlessness.
- CXR findings of diffuse pleural thickening include a smooth continuous pleural density affecting at least 25% of the lateral chest wall, sometimes with blunting of the costophrenic angle.
- Lung function tests may show a restrictive ventilatory defect.
- CT scan and biopsy may be required to differentiate diffuse pleural thickening from mesothelioma.
Benign asbestos-related pleural effusion
- Pleural effusions can occur within 10-20 years of asbestos exposure but may appear much later.
- A pleural biopsy is usually required to differentiate between benign and malignant pleural effusions.
- Benign effusions may require drainage if large and symptomatic but they may resolve spontaneously.
- Asbestosis is a typical pneumoconiosis (interstitial lung disease caused by inhaled inorganic dusts) and is caused by inhalation of asbestos fibres, with a latent period of 20-30 years.
- The development and severity of asbestosis is related to the degree and duration of asbestos exposure.
- There is typically an initial gradual onset of breathlessness and reduced exercise tolerance, sometimes with productive cough and wheezing.
- Progression of asbestosis may lead to fine bilateral inspiratory crackles, finger clubbing and cor pulmonale.
- Pulmonary function tests show reduced gas transfer, reduced lung volumes, a restrictive ventilatory defect and exercise-related hypoxaemia.
- CXR may be normal but usually shows bilateral lower zone interstitial changes, often with pleural plaques and thickening.
- High-resolution CT scans are more sensitive than CXRs.
- Biopsy and histological confirmation are not usually required.
- The prognosis of asbestosis is very variable and depends on the extent of lung involvement and the severity of COPD.
- Exposure to asbestos causes lung cancer independently of cigarette smoking.
- Lung cancer is most closely associated with long thin asbestos fibres.
- Asbestosis need not be present in a person developing lung cancer as a result of asbestos exposure.
- The diagnosis and management are the same as those for all patients with lung cancer.
See separate article Malignant Mesothelioma.
Studies have also shown an association between asbestos exposure and cholangiocarcinoma. There is evidence for an association between asbestos and urinary tract cancers. A link with laryngeal cancer and lymphoma is less certain.
- Patients with asbestos-related lung disease may be eligible for compensation through the Industrial Injuries Disablement Benefit (IIDB) from the Department for Work and Pensions (see link in 'Further reading & references', below) or a civil law claim for damages from the employer at the time of asbestos exposure.
- Under the UK Limitation Act 1980, patients have only three years in which to make a civil claim from the date they became aware of the asbestos-related disease caused by an act or omission of the proposed defendant.
- Various charities can also provide help and support on compensation (see Asbestos Victims Support Groups Forum UK link in 'Further reading & references, below).
Asbestos-related diseases cannot be prevented in people who work with asbestos. However, its effects can be limited by health and safety measures combined with regular medical surveillance.
The control of industrial asbestos exposure in the UK is subject to the Asbestos Control Regulations 2012. These specify the surveillance regimes required for people working with asbestos. The required schedule varies, depending on the degree of risk to the individual worker. For those at highest risk, a medical check at least every two years is required. This involves an occupational and respiratory history, a respiratory examination and lung function tests. Routine CXRs are no longer perfomed due to concerns over unnecessary exposure to radiation but are arranged if clinically indicated.
Further reading & references
- Berman DW; Apples to apples: the origin and magnitude of differences in asbestos cancer risk estimates derived using varying protocols. Risk Anal. 2011 Aug;31(8):1308-26. doi: 10.1111/j.1539-6924.2010.01581.x. Epub 2011 Feb 9.
- Malignant pleural mesothelioma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up; European Society for Medical Oncology (2010)
- Industrial Injuries Disablement Benefits - technical guidance; Dept for Work and Pensions
- Lung cancer - the diagnosis and treatment of lung cancer; NICE Clinical Guideline (April 2011)
- Lung cancer - suspected; NICE CKS, July 2005
- Asbestos Victims Support Groups Forum UK
- Tomioka K, Natori Y, Kumagai S, et al; An updated historical cohort mortality study of workers exposed to asbestos in a refitting shipyard, 1947-2007. Int Arch Occup Environ Health. 2011 Dec;84(8):959-67. doi: 10.1007/s00420-011-0655-2. Epub 2011 Jun 9.
- Jamrozik E, de Klerk N, Musk AW; Asbestos-related disease. Intern Med J. 2011 May;41(5):372-80. doi: 10.1111/j.1445-5994.2011.02451.x.
- Jiang L, Akatsuka S, Nagai H, et al; Iron overload signature in chrysotile-induced malignant mesothelioma. J Pathol. 2012 Nov;228(3):366-77. doi: 10.1002/path.4075. Epub 2012 Aug 2.
- Nishimura Y, Maeda M, Kumagai-Takei N, et al; Altered functions of alveolar macrophages and NK cells involved in asbestos-related diseases. Environ Health Prev Med. 2013 Mar 6.
- O'Reilly KM, Mclaughlin AM, Beckett WS, et al; Asbestos-related lung disease. Am Fam Physician. 2007 Mar 1;75(5):683-8.
- Asbestos related disease statistics; Health and Safety Executive (HSE)
- Projection of mesothelioma mortality in Great Britain; Health and Safety Executive, 2009
- Stayner L, Welch LS, Lemen R; The worldwide pandemic of asbestos-related diseases. Annu Rev Public Health. 2013;34:205-16. doi: 10.1146/annurev-publhealth-031811-124704. Epub 2013 Jan 4.
- Markowitz SB, Levin SM, Miller A, et al; Asbestos, Asbestosis, Smoking and Lung Cancer: New Findings from the North American Insulator Cohort. Am J Respir Crit Care Med. 2013 Apr 13.
- Asbestos Toxicological overview; Health Protection Agency, 2007
- Pairon JC, Laurent F, Rinaldo M, et al; Pleural plaques and the risk of pleural mesothelioma. J Natl Cancer Inst. 2013 Feb 20;105(4):293-301. doi: 10.1093/jnci/djs513. Epub 2013 Jan 25.
- Clin B, Paris C, Ameille J, et al; Do asbestos-related pleural plaques on HRCT scans cause restrictive impairment in the absence of pulmonary fibrosis? Thorax. 2011 Nov;66(11):985-91. doi: 10.1136/thoraxjnl-2011-200172. Epub 2011 Jul 1.
- Miles SE, Sandrini A, Johnson AR, et al; Clinical consequences of asbestos-related diffuse pleural thickening: A review. J Occup Med Toxicol. 2008 Sep 8;3:20. doi: 10.1186/1745-6673-3-20.
- Loomis D, Dement JM, Elliott L, et al; Increased lung cancer mortality among chrysotile asbestos textile workers is more strongly associated with exposure to long thin fibres. Occup Environ Med. 2012 Aug;69(8):564-8. doi: 10.1136/oemed-2012-100676. Epub 2012 May 12.
- Brandi G, Di Girolamo S, Farioli A, et al; Asbestos: a hidden player behind the cholangiocarcinoma increase? Findings from a case-control analysis. Cancer Causes Control. 2013 May;24(5):911-8. doi: 10.1007/s10552-013-0167-3. Epub 2013 Feb 14.
- Lauriola M, Bua L, Chiozzotto D, et al; Urinary apparatus tumours and asbestos: the Ramazzini Institute caseload. Arch Ital Urol Androl. 2012 Dec;84(4):189-96.
- Asbestos Exposure and Cancer Risk, National Cancer Institute (US)
- The Control of Asbestos Regulations 2012; Health and Safety Executive
- Medical surveillance for workers carrying out licensed work with asbestos; Health and Safety Executive, 2012
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Colin Tidy
Dr Laurence Knott
Prof Cathy Jackson