Human exposure to lead and new evidence of adverse health effects: Implications for analytical measurements

Abstract

Lead poisoning is a preventable condition caused by exposure to environmental sources such as lead-containing dust or lead-painted consumer products. The history of lead poisoning prevention has been defined to some extent by the quality of the analytical methods available for lead measurements whether in environmental samples or biological tissues and fluids. The quality of blood lead methods has improved so greatly over the last three decades that we now know far more about the adverse health effects from low-level exposures. Recent evidence suggests that effects such as deficit in IQ occur below the current (periodically revised) U.S. CDC threshold of 10μg/dL, such that no safe threshold appears to exist for children. Improvements in analytical techniques have also had an impact on the environmental measurement quality, yet many environmental thresholds have remained unchanged for decades. In light of our current understanding of the adverse health effects at low levels of exposure, new thresholds for lead in children’s products have been introduced by the U.S. CPSC. The adequacy of current analytical techniques to detect lead accurately at the new, lower thresholds is questionable. XRF offers the advantage of being rapid and nondestructive compared to techniques such as AAS that require extensive sample preparation. However, the accuracy of handheld XRF determinations of lead in painted toys is generally limited. A brief comparative study on the performance of several analytical techniques for the determination of lead in toys is presented at the end of this paper.

The concurrent decline of soil lead and children’s blood lead in New Orleans

“…Lead (Pb) poisoning has been known for at least 2,000 y, but its full extent was not recognized until the 1960s and 1970s. While commercial Pb production developed rapidly and dispersed massive quantities of Pb dust into the environment, appropriate analytical tools for measuring Pb evolved slowly (2). Pioneering research published in 1979 by Herbert Needleman (3) established that even small amounts of Pb affect children’s learning abilities.…”

Risk factors for children’s blood lead levels in metal mining and smelting communities in Armenia: a cross-sectional study

“…Children are more vulnerable to lead exposure because their digestive tract absorbs up to 50 % of the lead ingested (compared to 10–15 % in adults), the dose of lead contamination per unit body weight is higher and their developing brains are more susceptible to lead compared to adults [ 4 ]. There is no safe level of lead for children; even low lead levels in blood can significantly affect children’s cognitive abilities [ 5 ]. The US Centers for Disease Control and Prevention (CDC) recommends 5 μg/dl reference level of lead in the blood of children from 1 to 5 years old.…”

Dynamic Geochemistry of Tetraethyl Lead Dust during the 20th Century: Getting the Lead In, Out, and Translational Beyond

“…Prior to the 1940s it was impossible to measure lead at small enough quantities to understand TEL’s environmental and health effects. The evolution and application of improved analytical instrumentation for clinical studies drove the reduction of lead exposure guidelines [ 5 ].…”