Hi James,

As Salieri said to the Emperor, it's an interesting idea; however,
sterilization would not cure snails of parasites. Try looking up filariasis
and schistosomiasis (bilharzia) on the Web to see what's potentially at
risk. It's very hard to prevent the spread of diseases and parasites once
they are habituated in a new island or continent, for example, giardia,
smallpox, malaria, yellow fever, measles, hookworm, leprosy, elephantiasis,
and of course HIV. Just a few days ago, the arrival in Canada of an African
woman with a hemorrhagic fever made panicky headlines all over North
America, because it was thought (incorrectly, as it turned out) that she
might have Ebola fever, a very dangerous disease that is currently confined
to parts of Africa. Not to blow things out of proportion, but it's better to
be safe than sorry.

Andrew K. Rindsberg
Geological Survey of Alabama