The first major clinical study involving hundreds of asbestos workers was conducted by Dr. Merewether, a prominent medical researcher. His study indicates that one out of every 4 workers was suffering from asbestosis. His study also found that asbestosis had a latency period between exposure and the onset of the disease. Dr. Merewether provided a number of suggestions to increases the safety of workers from dust and air born asbestos particles. He also concluded asbestos workers should be warned of the risks associated with asbestos.