LEAD | Here in the United States, where lead-based paint was banned in 1978 and leaded gasoline
in 1986, we think of childhood lead poisoning as
largely a relic of our past. But in China, where lead
regulations have only recently been enacted, medical
professionals are eager to find more accurate ways of
Linda Nie, an associate professor of health sciences,
has developed a portable X-ray fluorescence (XRF)
system to measure lead in bone in vivo. She’s now
collaborating with physicians at Xinhua Hospital
in Shanghai to validate the unit among a group of
children with lead poisoning.
While blood lead reflects short-term exposure, bone
lead shows long-term exposure, since the majority
Testing for Lead, Halfway Across the World
Mof lead accumulates in the bone. Nie’s unit shoots a low-energy X-ray into the tibia bone and collects
specific signals if lead is present in the bone.
“We want to test whether the portable system is
usable. If this is doable, we can use the device in
some countries that don’t have access to a large
system,” she says.
“We also want to study the effectiveness of lead
chelation [removal of heavy metals]. Usually with
chelation, we will see blood levels decrease, but
they can increase over time because of storage
levels in bone.” Measuring lead levels in the bone,
then, could give a more accurate measure of
chelation efficacy. | A.R.