How do you prevent yourself from getting lead poisoning?

Plumbism. Most lead poisoning these days is exposure to lead dust when removing paint from older houses, wear a mask to prevent inhaling lead containing dust check the sil around a house if yoiu are going to plant vegetables, that it does not contain lead from previous work on a structure.
Avoid ingesting lead. Really? I wasn't sure if this was a serious question. Fortunately, most sources of lead have been identified and all but removed from the environment. Others are clearly marked on labels so always read the warnings of household chemicals. Google "lead exposure" for more information.