Years to Develop
Mesothelioma is characterized
by having a long latency period, which means that symptoms
do not develop until 20-50 years after exposure to what caused
it. The average age at which symptoms usually begin to appear
is around 60 years old. It is estimated that about 3,000 to
4,000 cases of mesothelioma are diagnosed each years in the
US. The number of cases reported each year is increasing.
Among men 55 years and older, a possible reason for the current
increase in diagnosed cases is due to asbestos use in their work
environment. Since the 1930's, asbestos has been used primarily
in factories, shipyards, and other industrial settings. It was not
until 1973 that work places began reducing asbestos exposure. The
cases now being seen have developed many years after a worker's
first exposure to asbestos back in the 1940s, 1950s and 1960s.