Dear of troy: All I could find was this one brief mention of lead poisoning symptoms occuring in adult because of loss of bone associated with age. A male who may have lead locked up in his bone, but through poor diet (low calcium and phosphate intake) and for lack of exercise loses bone mass, could mobilize enough lead to cause symptoms.

"There is also speculation that adult neurotoxic effects may occur
when lead is released from the bone as part of the aging process. "