We believe that somewhere around age 20, we'll begin to see low-lead exposed individuals surpass high-lead exposed individuals in bone mass density. Then, in the 50 to 60 age group ? the age at which any individuals will begin to experience a natural loss of bone ? we expect to see the high-lead exposed individuals losing more bone sooner.  -   James Campbell     Quotes
We believe that somewhere around age 20, we'll begin to see low-lead exposed individuals surpass high-lead exposed individuals in bone mass density. Then, in the 50 to 60 age group ? the age at which any individuals will begin to experience a natural loss of bone ? we expect to see the high-lead exposed individuals losing more bone sooner. James Campbell
 Age And Aging