Biomonitoring of Pesticides: Pharmacokinetics of Organophosphorus and Carbamate Insecticides

Details

• Personal Author:
  Timchalk C
• Description:
  This chapter highlights the application of pharmacokinetics to facilitate biological monitoring for organophosphorus and carbamate insecticide exposures. The overarching goal of human biological monitoring (biomonitoring) is to assess exposure to specific chemical agents by quantifying specific biomarkers (Angerer et al., 2007; Gil and Pla, 2001; Jakubowski and Trzchinka-Ochocka, 2005). With regard to pesticides, biomonitoring is focused primarily on the measurement of the parent compound and key metabolites or reaction products in biological matrices such as blood and urine (Barr et al., 2006). A meaningful biomonitoring strategy is based on sound pharmacokinetic principles that enable quantification of chemical specific dosimetry and biological response, which can then be used to inform risk in humans who are exposed to these agents. Pharmacokinetics is associated with the absorption, distribution, metabolism, and excretion (ADME) of the insecticides, and these studies provide important data on the amount of toxicant delivered to a target site as well as species-, age-, and gender-specific, as well as dose-dependent differences in biological response in both animals (relevant to toxicology) and humans (biomonitoring/risk assessment). These studies have been conducted with both organophosphorus and carbamate insecticides in multiple species, at various dose levels, and across different routes of exposure to understand in vivo pharmacokinetics which have important implications for the design of biomonitoring studies. For example, the determination of relevant biological matrices (urine, blood), needed detection limits, appropriate biomarker (i.e., parent vs metabolite), and relevant timing for sample collection can be readily discerned from the pharmacokinetics. Although these two major classes of pesticides share a common toxicological mode of action associated with their ability to target and inhibit acetylcholinesterase (AChE), chemical/metabolite biomarkers are distinctly unique between these classes of agents. Within each class (organophosphate vs. carbamate) many insecticides share some common metabolites (e.g., dialkyl phosphates for organophosphates); however, chemical specific metabolites (i.e., a-naphthol for carbaryl or trichloropyridinol for chlorpyrifos) are available which can be directly linked to a specific insecticide. This chapter is focused on biomonitoring, and builds upon previously published works that focused on the pharmacokinetics of organophosphorus and carbamate agents and the development of pharmacokinetic and pharmacodynamics models for these insecticides (Timchalk, 2001, 2006). [Description provided by NIOSH]
• Subjects:
  Biomarkers Blood Carbamates Energy Metabolism Environmental Exposure Hazardous Substances Insecticides Occupational Health Organophosphates Radiation Dosimeters Risk Assessment Risk Factors Safety Urine

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• Keywords:
  Biological Monitoring Biomonitoring Chemical Agents Dosimetry Exposure Levels In Vivo Study Metabolites Models Organophosphorus Compounds Organophosphorus Insecticides Organophosphorus Pesticides Pesticides Pharmacodynamics Risk Factors Toxins

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• ISBN:
  9780470410301
• Publisher:
  John Wiley & Sons, Inc.
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Book
• Place as Subject:
  OSHA Region 10 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  267-287
• NIOSHTIC Number:
  nn:20050578
• Citation:
  Anticholinesterase pesticides; metabolism, neurotoxicity, and epidemiology. Satoh T, Gupta RC, eds. Hoboken, NJ: John Wiley & Sons, Inc., 2011 Jan; :267-287
• Contact Point Address:
  Charles Timchalk, Biological Monitoring and Modeling, Pacific Northwest National Laboratory, Richland, Washington
• CAS Registry Number:
  Carbaryl (CAS RN 63-25-2) ; Chlorpyrifos (CAS RN 2921-88-2)
• Editor(s):
  Satoh T; Gupta RC
• Federal Fiscal Year:
  2011
• NORA Priority Area:
  Agriculture, Forestry and Fishing
• Performing Organization:
  Battelle Pacific Northwest Laboratories
• Peer Reviewed:
  False
• Start Date:
  20060901
• Source Full Name:
  Anticholinesterase pesticides; metabolism, neurotoxicity, and epidemiology
• End Date:
  20170831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:5312ec802d5eaeb43c385b0142ebc3f296f9e5e866fc4ab65ce392a820cce0e910aec26338ec29b707132e59c4e67295f809ae4ed2a649587f045d4a960db4d6
• Download URL:
  https://stacks.cdc.gov/view/cdc/210869/cdc_210869_DS1.pdf
• File Type:
  [PDF - 739.48 KB ]