Even with these crucial safety measures, however, childhood lead exposure remains a serious problem, linked to learning disabilities, attention deficit disorders, reduced IQ, impaired hearing and kidney damage. And since lead poisoning often occurs with no immediate symptoms, blood lead screening programs have been instituted nationwide to identify children with unsafe exposure.
In Kansas, where more than a quarter of all housing units were constructed before 1950 and are likely to have layers of old lead paint, the state recommends that all children be screened not once, but twice; at about 12 and 24 months of age. To help achieve this goal, the Kansas Healthy Homes and Lead Hazard Prevention Program conducts public education and collects blood specimens—with a focus on children enrolled in the state Medicaid program—and the Kansas Health & Environmental Laboratories (KHEL), the state public health laboratory, performs the blood lead analysis.
This ambitious program encountered one snag, however. Stacey Sandstrom, MS, who oversees blood lead testing at the KHEL, explained, “It’s really hard to get a one- or two-year-old to sit still while you prick their finger and collect the blood in a small capillary tube, and it can be traumatic for the children. Nurses really wanted a way to ease the collection process.”
KHEL staff granted their wish. “We took a lot of ideas from the state newborn screening program,” said Sandstrom, including the use of filter paper to collect a tiny blood spot instead of a tube of blood. With the much-reduced sample size, the laboratory scientists moved to a more sophisticated testing platform, an inductively coupled plasma mass spectrometer—that also happens to have a much lower detection limit—enabling the scientists to identify children with even minute levels of lead exposure so the exposure sources can be tracked down and abated.
The new method enables trained staff to collect blood specimens in the field and KHEL scientists to double their daily testing volume in the laboratory.
Prior to starting filter paper blood spot screening in 2003, the KHEL analyzed about 3,500 specimens a year. In 2010, with the new protocols and sample prep automation in place, the laboratory screened 13,000 specimens and reported 283 elevated blood lead levels at or above 10 mg /dL.
“To us, it’s been a success,” said Sandstrom, “because we’ve increased our screening across the state, we’ve increased awareness that lead is still an environmental health hazard, we’ve been able to implement new technology, and, really, on our own, we’ve found a way to make the program work.”
She said, “Even if the program helps just one additional child, we’ve made a difference.”