2007 Progress Report: Center for Children’s Environmental Health Research – Pesticide Exposure Assessment Project

EPA Grant Number: R831710C002
Subproject: this is subproject number 002 , established and managed by the Center Director under grant R831710
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: University of California Berkeley Center for Children’s Environmental Health Research
Center Director: Eskenazi, Brenda
Title: Center for Children’s Environmental Health Research – Pesticide Exposure Assessment Project
Investigators: McKone, Thomas , Barr, Dana Boyd , Bradman, Asa , Harnly, Martha
Institution: University of California - Berkeley
EPA Project Officer: Callan, Richard
Project Period: May 1, 2004 through October 31, 2008 (Extended to October 31, 2010)
Project Period Covered by this Report: May 1, 2007 through October 31, 2008
RFA: Centers for Children's Environmental Health and Disease Prevention Research (2003) RFA Text |  Recipients Lists
Research Category: Children's Health , Health Effects , Health


The Specific aims of this project are:

  1. to evaluate changes in maternal OP pesticide tissue distributions immediately before and after birth.
  2. to determine the best and most convenient matrix for assessing exposure to organophosphate pesticides in children.
  3. to quantify the relative contribution of diet to children’s OP pesticide exposures in agricultural and urban communities.
  4. to characterize urinary OP pesticide metabolite levels in preschool and school-aged children and identify correlates of exposure.

Progress Summary:

Specific Aims 1-3:
In October 2006, we completed data collection for the Organic Diet Study, the goal of which is to determine the relative contribution of diet and ambient exposures to children’s urinary pesticide metabolite levels. In July 2007, we began enrolling pregnant women in the Peripartum Excretion Study, through which we will investigate the pharmaco-kinetics of pesticide excretion during late pregnancy, parturition, and the postnatal period. Data collection includes blood and urine samples prior to delivery, blood samples on the day of the cesarean delivery, and blood and breastmilk samples after delivery. We also collect cord blood, infant meconium, and infant urine samples, and conduct a questionnaire with the mother.

Specific Aim 4: Correlates of Children’s Exposure
Preliminary analysis of DAP metabolite levels in CHAMACOS children at ages 6, 12, and 24 months indicate that dimethyl metabolites predominate over diethyl metabolites. Dimethyl levels increase with age and are higher in boys at older ages. Metabolite levels are higher in children who eat more fruits and vegetables and in children from homes in which agricultural workers do not store their work clothes in sealed containers. As noted last year, DAP levels in six month old children were higher during summer months compared to winter. A manuscript describing these results are in progress.

Other Studies:
Maternal Exposures
In July 2007, we published findings (described in Year 3) comparing organochlorine pesticide exposures in pregnant CHAMACOS women to those in the general U.S. population. Levels of DDT, DDE, hexachlorobenze, and β-hexachlorocyclohexane were higher in the CHAMACOS cohort, and were linked with birthplace in regions of Mexico with recent use of OC pesticides (Bradman 2007).

We are currently examining exposure to non-persistent chemicals, including fungicides; organophos-phate insecticides; pyrethroid, carbamate, and organochlorine insecticides; triazine and choroacetanilide herbicides; naphthalene; and pentachlorphenol. We have measured pesticide-specific metabolite levels in urine samples, and have developed a test for ETU, a toxic metabolite of bisdithiocarb-amate fungicides. Most metabolites had low detection frequencies, though nine were detected in >50% of the population. Two metabolites with high detection frequencies (TCPy and 1-napthol) derive from chemicals currently in local agricultural use (chlorpyrifos and carbaryl), though we did not find associations between field work and metabolite levels. Of 21 metabolites measured in both pregnant CHAMACOS and CDC National Health and Nutrition Examination Study (NHANES) participants, median levels for 5 [2,4-dichlorophenol, 2,5-dichlorophenol, 2-naphthol, para-nitrophenol and 3,4,6-trichloro-2-pyridinol (TCPy)] were significantly higher in CHAMACOS women (Castorina, in preparation).

Finally, our work on the Peripartum Study (described above) will help us understand a previous CHAMACOS finding: namely, that pregnancy urinary DAP metabolite levels spike at the time of delivery. If excretion in breastmilk is similarly high in this period, it may have implications for neonatal exposure.

Children’s Exposures
In July 2007, we published findings from our Quantitative Exposure Assessment (QEA) (described in Year 3). In August, our work on this project was recognized with an EPA 2007 Children's Environmental Health Excellence Award in the Science Achievement category.

Pathways of Exposure
In May 2007, we published a paper modeling pesticide exposures to pregnant CHAMACOS participants. Inputs to the model included CHAMACOS biomonitoring data, California pesticide use reporting (PUR) data, and environmental samples. Biomarker comparisons and model results support the observation that, relative to NHANES, the CHAMACOS population has a statistically significant (p < 0.001) added intake of OP pesticides with low inter-individual variability. We attribute the magnitude and small variance of this intake to residential non-dietary exposures from local agricultural OP use. These results show that mass-balance models can estimate exposures for OP pesticides within the range measured by biological monitoring.

We have also submitted a manuscript describing our field intervention to reduce pesticide exposure to farmworkers. Interventions included use of coveralls and gloves, and promotion of handwashing. Total median malathion dicarboxylic acid (MDA) metabolite levels were 2.5 times lower in farmworkers post-intervention. Levels were lowest in workers who wore gloves and did not eat strawberries fresh from the fields as they picked. Malathion was detectable on outerwear but not skin, suggesting that a removable layer of clothing (e.g. coveralls) could reduce take-home exposure.

We have also completed data collection for the Organic Diet Study (described above). Between October and April, with support from an EPA STAR fellowship, Lesliam Quiros collaborated with CDC chemists to develop a laboratory analysis for DAP levels in dust samples. All study dust samples have been analyzed for DAPS, and additional funds have been obtained to analyze the samples for parent OP compounds. Measurement of urinary metabolites will conclude in late fall. This project will generate the first data evaluating whether exposure to OP breakdown products in the environment may confound estimates of pesticide exposure based on urinary metabolite measurements.

Analysis of 323 breastmilk samples collected from CHAMACOS women near delivery and 191 samples collected 6-months post-partum is expected by February 2008. Rosana Weldon is collaborating with CDC chemists to develop methods to measure both non-persistent pesticides and persistent environmental chemicals in this medium. Experiments using solid phase micro-extraction and analysis by gas chromatography/ high-resolution mass spectrometry are promising and method validation is expected by October 2007. Ms. Weldon’s dissertation work with these data will be the first to investigate the utility of breast milk as a biomarker of exposure to non-persistent pesticides and to examine whether breast milk is a large source of exposure to these pesticides in children.

Future Activities:

We will complete field work for the Peripartum Excretion Study in fall, 2007. Manuscripts on correlates of child pesticide exposure, intra- and inter-subject variability in pesticide exposure, and levels of non-persistent pesticides in pregnant women will be completed in the next year.

Journal Articles on this Report : 5 Displayed | Download in RIS Format

Other subproject views: All 14 publications 14 publications in selected types All 14 journal articles
Other center views: All 135 publications 110 publications in selected types All 102 journal articles
Type Citation Sub Project Document Sources
Journal Article Bradman A, Fenster L, Sjodin A, Jones RS, Patterson Jr DG, Eskenazi B. Polybrominated diphenyl ether levels in the blood of pregnant women living in an agricultural community in California. Environmental Health Perspectives 2007;115(1):71-74. R831710 (2005)
R831710 (Final)
R831710C001 (2007)
R831710C002 (2007)
R834513 (2010)
  • Full-text from PubMed
  • Abstract from PubMed
  • Associated PubMed link
  • Journal Article Bradman A, Whitaker D, Quiros L, Castorina R, Claus Henn B, Nishioka M, Morgan J, Barr DB, Harnly M, Brisbin JA, Sheldon LS, McKone TE, Eskenazi B. Pesticides and their metabolites in the homes and urine of farmworker children living in the Salinas Valley, CA. Journal of Exposure Science and Environmental Epidemiology 2007;17(4):331-349. R831710 (2005)
    R831710 (Final)
    R831710C001 (2007)
    R831710C002 (2007)
  • Abstract from PubMed
  • Full-text: Nature - Full Text HTML
  • Abstract: Nature - Abstract
  • Other: Nature - Full Text PDF
  • Journal Article Eskenazi B, Bradman A, Harley K, Holland N. Indicadores biologicos de exposicion a pesticidas y su relacion con la salud de los ninos. Acta Toxicologica Argentina 2006;14(Supplement):63-65. R831710 (2005)
    R831710C001 (2007)
    R831710C002 (2007)
    R832734 (2006)
    not available
    Journal Article McKone TE, Castorina R, Harnly ME, Kuwabara Y, Eskenazi B, Bradman A. Merging models and biomonitoring data to characterize sources and pathways of human exposure to organophosphorus pesticides in the Salinas Valley of California. Environmental Science & Technology 2007;41(9):3233-3240. R831710 (2005)
    R831710 (Final)
    R831710C001 (2007)
    R831710C002 (2007)
  • Abstract from PubMed
  • Full-text: ACS-Full Text HTML
  • Abstract: ACS-Abstract
  • Other: ACS-Full Text PDF
  • Journal Article Montesano MA, Olsson AO, Kuklenyik P, Needham LL, Bradman AS, Barr DB. Method for determination of acephate, methamidophos, omethoate, dimethoate, ethylenethiourea and propylenethiourea in human urine using high-performance liquid chromatography-atmospheric pressure chemical ionization tandem mass spectrometry. Journal of Exposure Science and Environmental Epidemiology 2007;17(4):321-330. R831710 (2005)
    R831710 (Final)
    R831710C002 (2007)
  • Abstract from PubMed
  • Full-text: Nature Publishing - Full Text HTML
  • Abstract: Nature Publishing - Abstract
  • Other: Nature Publishing - Full Text PDF
  • Supplemental Keywords:

    exposure, pesticides, pregnant women, children, organophosphate, DDT, agriculture,, RFA, Health, Scientific Discipline, ENVIRONMENTAL MANAGEMENT, PESTICIDES, Health Risk Assessment, Children's Health, Pesticide Types, Risk Assessment, health effects, pesticide exposure, community-based intervention, airway disease, environmental risks, respiratory problems, Human Health Risk Assessment, insecticides, assessment of exposure, childhood respiratory disease, environmental health hazard, children's environmental health, outreach and education, agricultural community, allergen

    Relevant Websites:

    http://www.chamacos.org Exit

    Progress and Final Reports:

    Original Abstract
  • 2004 Progress Report
  • 2005 Progress Report
  • 2006 Progress Report
  • 2008
  • 2009
  • Final

  • Main Center Abstract and Reports:

    R831710    University of California Berkeley Center for Children’s Environmental Health Research

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R831710C001 Center for Children’s Environmental Health Research – CHAMACOS Community Based Research Project
    R831710C002 Center for Children’s Environmental Health Research – Pesticide Exposure Assessment Project
    R831710C003 Center for Children’s Environmental Health Research – Mechanisms of Pesticide Neuro- and Immunotoxicity
    R831710C004 Center for Children’s Environmental Health Research – Community Outreach and Translation Core