John F. Rosen, 77, a pediatrician whose discovery of high levels of lead poisoning among the New York City children he treated propelled him to campaign for a national effort to prevent the condition, died of colon cancer Dec. 7 in Greenwich, Conn.

Concerned about the levels of lead in his young patients and knowing that lead poisoning diminished mental capacities irreversibly, Dr. Rosen helped establish one of the nation's first and largest clinics to lead poisoning.

He went on to push New York City to adopt stricter standards for removing lead paint from tens of thousands of old buildings.

He served on committees of the National Academy of Sciences and urged spending tens of billions of dollars to remove lead paint from tens of millions of homes, calculating that lead exposure harmed far more children than asbestos. - N.Y. Times News Service