Jeffrey Dupler, Section Manager
517-335-8244
duplerj@michigan.gov

The adverse health effects resulting from exposure of young children to environmental lead has received increasing attention in recent years. The major sources of exposure to lead in housing units are thought to be paint, dust, and soil. Food, water, and airborne lead are also potential sources of but are considered to be minor sources of exposure. Currently, lead-based paint is receiving emphasis as a critical area of concern and a principal medium for lead contamination and exposure. Although less consideration has been given to soil contaminated with lead from petroleum additives or from the leaching of exterior paint (near driplines, etc.), contaminated soil may be tracked into homes. Like dust, it becomes collected on hands,toys, and food and is ingested. Concentrations in paint, dust, and soil must be determined if a comprehensive approach to the problem of lead ingestion from housing sources is to be established.

PRINCIPLES OF THE TEST

The laboratory analyzes paint chips, soil and dust wipes for evidence of lead content. The analyses are performed on a flame atomic absorption spectrophotometer and the absorbence is measured as the element's characteristic wavelength. The method depends on the fact that metallic elements in the ground state will absorb light of the same wavelengths they emit when excited. A hollow cathode lamp whose cathode is made of the element to be determined is used as the source. Its radiation passes alternately through and around a flame into which the sample is being aspirated. The solution is atomized and the metal atoms released absorb light at their characteristic wavelengths in proportion to their concentration in the flame. A monochromatic isolates the characteristic radiation of the element being analyzed and a photomultiplier tube measure the intensity of the transmitted radiation from the two lights paths to obtain the absorbance.

Related Information

 Lead Hazard Remediation Program & Childhood Lead Poisoning Preventation