Pleural Plaques are calcified deposits which occur on the surface of the lung, and are a symptom of exposure to the fibres in asbestos and are formed over decades. Whilst they are a sign of asbestos exposure, in the opinion of medical experts they do not cause breathlessness, respiratory injury, or loss of lung capacity. However, for those suffering from pleural plaques, they are the subject of great anxiety as they are evidence of asbestos exposure, meaning that those suffering with pleural plaques are at risk of more serious asbestos related illnesses, such as mesothelioma.