The 10 years prior to them being banned, 6700 children were treated in hospitals for injuries to them. A lawn dart thrown a very short distance lands with over 20,000 lbs of force per square inch. Guns can be used to kill people, it's not really a surprise. I don't think anyone bought lawn darts with the idea of killing people, or that they even could, in mind.
Astronauts can soak upwards of 2 Sv. on a 6-month ISS tour, although it's highly variable. Space is great for charged particles accelerating to above-thermal velocities. My dosimeter tops out at 6 MeV, but our machines produce at up to 21 MeV, depending on the patient's prescription. But if I'm ever exposed during beam.. I'm probably dead. Though the high voltage is a bigger health hazard to me than the radiation.
