Plutonium IS toxic
Dominant mechanisms of toxicity are associated with alpha radiation
https://www.atsdr.cdc.gov/toxprofiles/tp143.pdf
There is sufficient evidence in humans that inhalation of plutonium-239 aerosols causes lung cancer, liver cancer and bone sarcoma. Exposure to plutonium-239 also entails exposure to plutonium-240 and other isotopes. /Plutonium-239/