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Extramural Research

CHAMACOS Cohort Project

EPA Grant Number: R834513C001
Subproject: this is subproject number 001 , established and managed by the Center Director under grant R834513
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Center for the Health Assessment of Mothers and Children of Salinas - UC Berkeley School of Public Health: CHAMACOS Office, Berkeley, CA
Center Director: Eskenazi, Brenda
Title: CHAMACOS Cohort Project
Investigators: Eskenazi, Brenda
Current Investigators: Eskenazi, Brenda , Arora, Manish , Bradman, Asa , Chevrier, Jonathan , Eisen, Ellen , Harley, Kim , Holland, Nina T. , Johnson, Caroline , Lustig, Robert , Sjodin, Andreas , Smith, Donald
Institution: University of California - Berkeley
EPA Project Officer: Callan, Richard
Project Period: August 1, 2009 through July 31, 2014 (Extended to July 31, 2016)
RFA: Children's Environmental Health and Disease Prevention Research Centers (with NIEHS) (2009)
Research Category: Children's Health



Children of farmworkers in California are exposed to a unique mix of chemicals that may affect both their reproductive and neurobehavioral development. Potential exposures include the pesticide dichlorodiphenylthrichloroethane (DDT), which was recently used in Mexico where most of their farmworker parents originated; manganese (Mn), which is a key component of some widely used agricultural fungicides; and polybrominated diphenyl ether (PBDE) flame retardants, which are prevalent in California due to the state's strict flammability standards. DDT, Mn, and PBDEs are endocrine disruptors and neurotoxicants in animals, but studies in humans are limited. Age at onset of puberty in girls has declined in recent decades, possibly due to endocrine-disrupting compounds like DDT, Mn, and PBDEs, but almost no studies have examined pubertal onset in boys. These pollutants may also jeopardize children's cognitive development, particularly with exposure during the prenatal and peri-adolescent periods of peak brain growth. We propose to investigate the associations of DDT, Mn, and PBDE exposure in utero and at age 9 with puberty onset and neurodevelopment in the CHAMACOS longitudinal cohort of Mexican-American boys in the Salinas Valley, California. Boys enrolled in the CHAMACOS Study have been followed since before birth until 7 years of age. We will continue to follow these boys from age 9 to 13 years and enroll ~150 new 9 year-old-boys from the same source population, expanding the study from -150 boys to 300. We have measured DDT and PBDE levels in prenatal maternal blood (original cohort) and will back-extrapolate prenatal levels from maternal blood collected at 9 years (new enrollees). Prenatal Mn exposure will be measured in boys' teeth. DDT, Mn, and PBDE concentrations at age 9 will be measured in boys' blood.

Expected Results:

We will assess the relationship of in utero (measured or extrapolated) and age 9 (measured) concentrations of DDT, Mn, and PBDEs with neurodevelopment (specifically general cognition, attention, memory, motor, executive function, and social cognition) and with the timing and tempo of their pubertal onset as assessed by clinical Tanner exams conducted every 9 months between age 9 and 13 years and hormone levels measured at 12 years. Thus, this proposal takes advantage of a rich dataset of Mexican-American children participating in the CHAMACOS longitudinal cohort study and proposes to expand this unique cohort and follow the children into early adolescence.

Publications and Presentations:

Publications have been submitted on this subproject: View all 44 publications for this subprojectView all 282 publications for this center

Journal Articles:

Journal Articles have been submitted on this subproject: View all 33 journal articles for this subprojectView all 60 journal articles for this center

Supplemental Keywords:

Exposure assessment, environmental, disease, toxin, health effects, child health, biomarkers, epigenetic, DNA methylation, reproductive health, neurobehavioral health, pubertal onset, metabolic syndrome, obesity, cognition, attention, memory, motor, executive function, social cognition, infants, children, latino, farmworker, agriculture, pesticide, fungicide, PBDE, DDT, Mn, California, CA, Salinas Valley, community-based, deciduous teeth, back-extrapolation, GIS, maternal,, RFA, Health, Scientific Discipline, INTERNATIONAL COOPERATION, Health Risk Assessment, Biochemistry, Children's Health, Environmental Policy, Biology, pesticide exposure, farmworkers, flame retardants, PBDE, children's vulnerablity, neurochemical effects, harmful environmental agents, biological markers, agricultural community

Progress and Final Reports:
2010 Progress Report
2011 Progress Report
2012 Progress Report
2013 Progress Report

Main Center Abstract and Reports:
R834513    Center for the Health Assessment of Mothers and Children of Salinas - UC Berkeley School of Public Health: CHAMACOS Office, Berkeley, CA

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R834513C001 CHAMACOS Cohort Project
R834513C002 Exposure Project
R834513C003 Epigenetics Project
R834513C004 Community Outreach and Translation Core

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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