What is a viable explanation as to why some individuals suffer stem cell damage when exposed to chemical agents but others do not?

Amalgam placed in the cavity preparation is most often accomplished by using a

amalgam carrier. condenser. burnisher. carver.

The administration of radioactive drugs and the operation of radiation detection instruments is performed by a ____. 

A. medical technologist B. respiratory therapy technician C. medical laboratory technician D. nuclear medicine technologist E. radiographer