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, according to a study by Dr. Brian Schwartz of Johns Hopkins and Dr. Howard Hu of University of Michigan.
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.
"We're trying to offer a caution that a portion of what has been called normal aging might in fact be due to ubiquitous environmental exposures like lead. The fact that it's happening with lead is the first proof of principle that it's possible," said Dr. Schwartz, a leader in the study of lead's delayed effects. Other pollutants like mercury and pesticides may do the same thing, he said.