Leaded gas was used from the '20s to the '80s. People who are older now lived through that time. There were, and still are, many ways to be exposed to lead. When it rained, lead in the air from leaded gas exhaust fumes was carried into the soil and groundwater, where it found its way inside fruits and vegetables. Lead paint can chip, fall to the ground, get ground up on the floor and float through the air.
Smoking increases lead levels in the body.
People in some occupations, such as metal workers, solderers, plumbers and demolition workers, were more likely to be exposed than others. When lead enters the body, it goes to three places. It enters the bloodstream, and remains for about two weeks. During that time it circulates to the soft tissues, from the kidneys to the brain, where it remains for a month or so. What's more disturbing is what happens when lead gets into the bones.