Dr. John F. Rosen, 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 on Dec. 7 in Greenwich, Conn. He was 77.
The cause was colon cancer, his wife, Margaret, said.
When he arrived at Montefiore Medical Center in the Bronx in 1969, Dr. Rosen was mainly interested in how children’s bodies absorb calcium. But within a few years, concerned about the levels of lead he was seeing in his young patients and knowing that lead poisoning diminished mental capacities irreversibly, he embarked on a mission. Dr. Rosen helped establish one of the nation’s first and largest clinics for the treatment of lead poisoning; he personally supervised the treatment of 30,000 children. In one advance, he developed X-ray techniques for measuring lead in children’s bodies.
He went on to push New York City to adopt stricter standards for removing lead paint from tens of thousands of older buildings. (The use of lead paint had been outlawed in 1978.) In 1991 he led a committee at the Centers for Disease Control and Prevention in Atlanta that lowered the threshold at which children are considered to be poisoned by lead, to 10 micrograms per deciliter of blood from 60 micrograms.
But even that threshold was too high, Dr. Rosen believed, and he immediately began lobbying to reduce it further. This year, the C.D.C. halved it to 5 micrograms. The change could not help those who had lead in their bodies, but it sounded an alarm that even infinitesimal quantities of lead could be dangerous.
“It’s about time,” Dr. Rosen said.
He cited his own and others’ studies showing that lead poisoning harms a person’s ability to think and plan, as well as physical coordination. For a child with an I.Q. of 85, he said, lead exposure “could mean the difference between a menial job in a fast-food restaurant or a meaningful career.”
Dr. Rosen’s ambition was to eventually eradicate lead poisoning by eliminating exposure to lead altogether, in the manner that vaccines reduced the incidence of polio to almost none. He served on committees of the National Academy of Sciences and urged spending tens of billions of dollars to remove old lead paint from tens of millions of homes, calculating that lead exposure harmed far more children than asbestos.
Landlords and some government officials disputed the need for such a large-scale effort, arguing that lead poisoning had dropped sharply in recent decades as lead was removed from gasoline and that the use of lead paint had abated.
Dr. Rosen often testified in suits against property owners, leading some to suggest that his crusade was motivated by the prospect of personal financial gain from payments by plaintiffs’ lawyers.
He also had critics in the news media. In 2003 Andrew Wolf, then a columnist for The New York Sun, argued that the war against lead poisoning had been won and accused Dr. Rosen of practicing political, not medical, science. In 1992, Newsday questioned whether he was a “well-meaning prophet or merely an alarmist.”
Dr. Rosen replied: “I am not an alarmist. I cannot keep quiet when kids’ futures are at stake.”
John Friesner Rosen was born in Manhattan on June 3, 1935. His parents volunteered for civil rights and leftist causes and traveled to China to meet with Chou En-lai before President Richard M. Nixon’s historic trip there in 1972.
Dr. Rosen graduated from Harvard and the College of Physicians and Surgeons of Columbia University, did his residency at the Columbia-affiliated Babies Hospital and became a researcher at Rockefeller University. He moved on to Montefiore, where he became a pediatrics professor and head of environmental sciences at its Children’s Hospital. His focus was underprivileged children living in substandard housing.
In one instance, he encountered two young sisters who had made repeated visits to the hospital with very high levels of lead in their blood. He decided to accompany them home, but the home, he discovered, had been inspected and the paint found safe. He then accompanied them to a park, where they climbed up and down a fence. It was covered with lead paint.
Dr. Rosen started his lead clinic in the early 1970s. He later opened “safe houses,” where families could come while lead paint was removed from their homes. When lead paint was discovered in a Manhattan elementary school in 1992, he spoke out, calling the school “a toxic dump.” It was closed for a cleanup.
Dr. Rosen lived in Stamford, Conn. His first marriage, to Katharine Lardner, ended in divorce. He is survived by his wife, the former Margaret Hiatt; two children from his first marriage, Carlo, a physician, and Ellis Lesser; a daughter from his second marriage, Emily Reilly; and nine grandchildren.
Dr. Rosen’s concerns about lead poisoning went beyond residents of low-income housing. In 1988, he warned against eating Florida grapefruits because they had been sprayed with lead arsenate to speed ripening. Two years later, he reported seeing 30 or 40 cases of lead poisoning each year among children of wealthy people who had bought and restored brownstones.
