LIMITS TO PUBLIC HEALTH INVESTIGATIONS

Even though asbestos exposure is the most likely cause of mesothelioma, it is often difficult to determine if, where, and when a person with mesothelioma was exposed to asbestos. The long latency period, along with the high degree of mobility of the population, makes determining a definite place and time of exposure difficult.

Some areas in Montana seem to have had more mesothelioma cases than others. Based on the standard morbidity ratio, Lincoln, Cascade, and Rosebud counties had more people diagnosed with mesothelioma from 1979 to 2002 than would be expected based on their populations. Gallatin County had fewer people diagnosed with mesothelioma than expected.

Since available registries do not include residential histories, it is unknown how long these Montanans lived in these counties. Due to the high mobility of the population, they may have lived elsewhere before moving to the counties where they were diagnosed.