I'm not sure of the procedures used to protect the Apollo astronauts, but it hasn't worked very well [0]. Though, NASA says that its too early in the process to make any conclusions [1].

The key conclusion of the study:

> They found the Apollo astronauts’ mortality rate from cardiovascular disease was as much as five times higher than for astronauts who never flew, or for those who flew low-altitude missions aboard the space shuttle that orbited a few hundred miles above Earth.

[0] https://www.rt.com/usa/353865-apollo-study-heart-disease/

[1] http://www.reuters.com/article/us-space-health-astronauts-id...

IIRC moon in just inside the earth's magnetosphere.