It is sometimes difficult to prove the relationship between asbestos exposure and the development of mesothelioma. The risk of developing the disease begins about 15 years after the first exposure and increases each year up to 40 to 45 years after the first exposure. It is estimated that about 8 million people living in the United States have been occupationally exposed to asbestos over the last half century during the mining and milling of the mineral and during various manufacturing processes.
