Non-invasive biomonitoring approaches to determine dosimetry and risk following chemical exposure: analysis of lead and organophosphate insecticide in saliva.
Timchalk-C; Yantasee-W; Liu-G; Lin-Y
Toxicologist 2006 Mar; 90(1):310-311
Approaches are needed to quantify exposures to a broad-range of chemicals and to rapidly determine the implications to human health. Non-invasive biomonitoring approaches are being developed using portable analytical systems. Biomonitoring for lead (Pb) is based upon a blood Pb concentration; however, saliva is suggested as an alternative biological matrix. Saliva has recently been used to quantify dosimetry following exposure to the insecticide chlorpyrifos in rats by measuring the major metabolite, trichloropyridinol (TCP), and saliva cholinesterase inhibition. To advance non-invasive biomonitoring, portable microfluidic/electrochemical devices are being developed for the rapid analysis of heavy metals, like lead (Pb), or trichloropyridinol (TCP), based on anodic stripping voltammetry and bioelectrochemical magnetic immunosensing, respectively. These systems demonstrate good linear response over broad concentration ranges (1 - 2000 ppb). Pharmacokinetic studies have been conducted in rats to assess the relationship between saliva and blood (plasma & RBC) Pb and TCP concentrations as a function of dose and time. For both chemicals, the pharmacokinetics provides a framework for quantifying dosimetry based on a saliva measurement. Physiologically based pharmacokinetic (PBPK) models for Pb and chlorpyrifos can then be used to simulate blood and saliva concentrations. These results suggest that technology developed for non-invasive biomonitoring provides a sensitive, and portable analytical tool capable of assessing exposure in real-time. By coupling these non-invasive technologies with PBPK modeling it is feasible to quantify exposure to a broad range of chemical agents involving multiple routes of exposure (i.e. skin, ingestion, inhalation). In summary, it is envisioned that once fully validated, these monitoring and modeling approaches will be very useful for accessing human exposure and health risk.
Dosimetry; Lead-compounds; Insecticides; Exposure-levels; Exposure-assessment; Laboratory-animals; Animals; Animal-studies; Agricultural-chemicals; Heavy-metals; Metals; Risk-factors; Health-hazards
Research Tools and Approaches: Exposure Assessment Methods
The Toxicologist. Society of Toxicology 45th Annual Meeting and ToxExpo, March 5-9, 2006, San Diego, California
Battelle Memorial Institute, Richland, Washington