It's being called a Public Health Threat.  A Pennfield man is hospitalized, the CDC has been contacted and authorities are trying to figure out how a poison that once was used to make rat poison ended up in the man's system, the Lansing State Journal reports.

Thallium has been banned since 1970.

Tests results on family members' exposure are pending.  Authorities are also looking into the man's employer, to see if it's possible he came in contact with it there.

It is possible this type of deadly poisoning can be from methamphetamine production or old stockpiles of rat poison, James Rutherford, health officer for the Calhoun County Health Department, told the LSJ, though he also said that "some thallium poisonings have been intentional" so the sheriff's department and members of the Major Crimes Task Force are trying to figure out if there is thallium in the community.