According to http://www.academia.edu/3586500/Half-Lives_The_Rise_and_Fall... :

Martland, on the other hand, emerged as a champion against any internal medical use of radium, alerting the AMA to its potential dangers as early as 1925

That's "Some Unrecognized Dangers in the Use and Handling of Radioactive Substances", at http://jama.jamanetwork.com/article.aspx?articleid=238584 . It includes:

when long lived radioactive substances are introduced into the body ... death may follow a long time after, from the effects of constant irradiation on the blood-forming centers.

Joliot-Curie was awarded her doctorate in 1924.