Although cobalt can be solid and even radioactive, the primary risk of cobalt exposure for most workers, including refinery and mining workers, comes from cobalt dust.
Routes of Entry: Inhalation, skin and eyes.
Potential Harms: Cobalt and cobalt compounds pose risks of harm to the human respiratory system. Although not conclusively proven at this point, cobalt exposure has been linked to death from lung cancer and cardiomyopathy. Other chronic effects include respiratory irritation, diminished pulmonary function, wheezing, asthma, pneumonia, and fibrosis.
If you want more detailed and clinical information about occupational cobalt exposure,there’s an excellent CDC source you should check out, https://www.atsdr.cdc.gov/toxprofiles/tp33.pdf
Hope that helps and apologies for taking so long to reply.
Glenn Demby
203 354-4532