Is Pleural Thickening Always a Sign of Asbestos Exposure?
While pleural plaques nearly always indicate asbestos exposure, pleural effusions and pleural thickening can be caused by other factors. Effusions can be caused by a number of factors, including congestive heart failure. Widespread pleural thickening can be caused by empyema (pus in the pleural space), tuberculosis, pleuritis, or hemothorax, as well as asbestos exposure. It generally takes about 15 years from the initial asbestos exposure for pleural thickening to be evident. Researchers do not understand why asbestos exposure triggers pleural thickening, but inflammation and fibrosis of the lymph nodes in the chest area is thought to play a role.
