Pleural Plaques are calcified deposits which have developed on to the surface of the lung, and occur as a result of exposure to asbestos, and particularly the fibres in asbestos, and appear over a long passage of time.
They do not cause respiratory injury or breathlessness as other asbestos related illnesses do, but for those suffering with them they are cause for deep concern. This is because they suggest asbestos exposure, meaning that the sufferer is at a higher risk of mesothelioma and other more serious illnesses caused by asbestos exposure.
Having said that, normal respiratory function can be impaired if the plaques are of a sufficient size, as they may cause a reduction in ventilatory capacity, but to a smaller extent than a disease such as pleural fibrosis.
It is difficult to ascertain a figure for those suffering from pleural plaques as there is a great deal of uncertainty with factors such definition of cases, duration of follow up and the data sources, but taking into account these variation, it is estimated that between a third and half of those exposed to asbestos in the work place end up suffering from calcified plaques thirty years after the exposure and an estimated 10% will experience uncalcified plaques twenty years after.
X-rays sometimes struggle to pick up plaques, as their sensitivity is unable to detect a plaque which is below a certain density. Therefore post-mortem is a more effective method when it comes to identifying pleural plaques in the lung.
Professions where pleural plaques commonly occur include pipe fitters and insulators and an assumption has been made from past cases that the larger the plaque the more likely it is to be calcified as larger plaques imply increased fiber burdeen.
Suffering from plaques is not the only indicator of exposure to asbestos and it’s fibres, as there are many cases where a patient has no sign of pleural plaques yet still as the same fiber burden as a patient with pleural plaques.