Dust spells danger for young minds

 作者:寇匮卣     |      日期:2019-03-08 02:16:04
By Nell Boyce in Washington DC KEEPING houses clean can prevent children accumulating dangerous levels of lead in their blood, a new study has confirmed. The blood of children who live in old housing with flaking, lead-based paint often contains high levels of lead. Mopping up dust helps children with the highest lead levels, but no one knew whether it made any difference to the much larger number with blood levels between 100 and 300 micrograms per litre. There are more than a million such children below the age of six in the US alone, and these doses can still be enough to impair mental development, experts say. So George Rhoads of the Environmental and Occupational Health Sciences Institute in Piscataway, New Jersey, asked the families of 56 toddlers to let cleaners come to their houses every few weeks for a year. They wet-mopped floors, sponged walls and sucked up dust with a powerful vacuum cleaner. At the end of the year, the children’s blood lead levels had fallen by an average of 17 per cent. And in homes cleaned 20 times or more, blood lead concentrations were cut by 34 per cent (Pediatrics, vol 103, p 551). Blood lead levels did not change in children from homes not visited by the cleaning teams. “Cleaning really does make a difference,” says Rhoads. But Bruce Lanphear of the Children’s Hospital Medical Center in Cincinnati, Ohio,