Latency Time of Plaques in Relation to Asbestos Exposure

Latency time. Plaques are more related to time after exposure than to the dose. Very few plaques will be seen earlier than 15 years after the first exposure to asbestos, and most will appear only after 30 years.

In areas where the population is exposed from birth the first pleural changes will appear after age 30 and the incidence then increases with age.

Thus, occurrence of plaques is dependent on cumulative exposure and time since first exposure.

Many plaques are not seen until long after exposure has ceased. Once seen, they will slowly grow larger over the years, and with time many will calcify.