Occupational exposure to cement dust: changing opinions of a respiratory hazard.

In the twentieth century medical experts reversed their opinion on whether exposure to cement dust was hazardous. Today it is associated with bronchitis, chronic obstructive pulmonary disease, silicosis, and lung cancer. Yet, up to the 1970s experts maintained that the dust was harmless. Being exposed on a daily basis, workers and their unions were in a unique position see the effects of cement dust and frequently raised concerns. However, lay knowledge, no matter how accurate it later proved to be, was ignored by those in authority. This paper examines the origins of the theory that cement dust was harmless, the social context in which the theory became popular, the consequences for workers' health, and the theory's ultimate rejection.