杏吧原创

CHILDREN poisoned by lead in America鈥檚 inner-city slums have failed to
benefit from a drug which flushes the metal from their bodies. This failure
suggests that brain damage caused by early exposure to the metal may be
irreversible, the researchers say.

The failure of the drug 鈥渢akes away the only quick fix available鈥�, says
Walter Rogan of the National Institute of Environmental Health Sciences at
Research Triangle Park in North Carolina. 鈥淭his was the best hope for fixing
kids after they鈥檝e been exposed,鈥� he says.

Rogan and his colleagues studied the development of 780 inner-city toddlers
in several major US cities. The children had 20 to 44 micrograms of lead per 100
millilitres of blood. Levels as low as 5 micrograms have been linked to impaired
educational development.

Half the children received succimer, a drug which traps lead and carries it
out of the body. The rest were given a placebo. Three years later, levels of
lead in the treated children were lower by an average of 4.5 micrograms per 100
millilitres of blood. But IQ scores were the same as before in all the
children.

Rogan says that most of the poisoning is due to flaking lead paint applied to
windows and doors in millions of inner-city tenements built in the early 1960s.
Children absorb most lead as toddlers, crawling around on the floor and eating
scraps of food contaminated with metal-laden dust.

City authorities must now focus on preventing exposure from contaminated
housing, says Rogan. 鈥淚t means we need to focus on housing, not the kids,鈥� he
says. 鈥淜ids should not live in houses that poison them.鈥� Options include sealing
old paint so it can鈥檛 flake, or completely replacing painted doors and windows.