Early lead exposure may hasten old-age mental decline
Could it be that the "natural" mental decline that afflicts many older people is related to how much lead they absorbed decades before?
That's the provocative idea emerging from some recent studies, part of a broader area of new research that suggests some pollutants can cause harm that shows up only years after someone is exposed.
The new work suggests long-ago lead exposure can make an aging person's brain work as if it's five years older than it really is. If that's verified by more research, it means that sharp cuts in environmental lead levels more than 20 years ago didn't stop its widespread effects.
"The fact that it's happening with lead is the first proof of principle that it's possible," said Schwartz, a leader in the study of lead's delayed effects. Other pollutants like mercury and pesticides may do the same thing, he said.
In fact, some recent research does suggest that being exposed to pesticides raises the risk of getting Parkinson's disease a decade or more later. Experts say such studies in mercury are lacking.
The notion of long-delayed effects is familiar; tobacco and asbestos, for example, can lead to cancer. But in recent years, scientists are coming to appreciate that exposure to other pollutants in early life also may promote disease much later on.
http://edition.cnn.com/2008/HEALTH/01/28/aging.brain.ap/index.html