A new study has shown that even small amounts of lead in the bodies of healthy children and teens could worsen kidney function. It was done by Johns Hopkins Children's Center
In 1991, U.S. Centers for Disease Control and Prevention (CDC) reduced the lead level "of concern" for children from 30 micrograms to 10 micrograms per deciliter of blood, but the suggest that even levels below 10 present a health risk, providing the first evidence that lead levels that low may impair kidney function.
"To our knowledge, this is the first study to show that very low levels of lead may impact kidney function in healthy children, which underscores the need to minimize sources of lead exposure," said lead author Jeffrey Fadrowski, a paediatric nephrologist at Johns Hopkins Children's Center.
Of the 769 healthy children and teens in the study, ages 12 to 20, more than 99 percent had lead levels below 10, with an average level of 1.5 micrograms per deciliter.
Those with lead levels in the upper quarter of the normal range appeared to have worse kidney function than children with lower lead levels. Kidney function is defined by the speed with which the kidneys filter the blood.
Those with lead levels above 2.9 had a kidney filtration rate 6.6 units (milliliters of blood filtered per minute and adjusted for body size) lower than children whose lead levels were below 1 microgram per deciliter.
Researchers also found that for each twofold increase in the amount of lead in the blood, the kidney's filtration capacity dropped by 2.3 units in males and by 3.3 in females.
The link between higher lead levels and worse kidney function persisted even after investigators eliminated high blood pressure - less than 5 percent of those in the study had it - as a possible factor affecting kidney status.
The study has been published in the Jan. 11 issue of Archives of Internal Medicine. (ANI)