Exposures & Health of Farm Worker Children in California

University of California at Berkeley

Exposures and Health of Farm Worker Children in California
Brenda Eskenazi, Ph.D.
eskenazi@uclink4.berkeley.edu
http://ehs.sph.berkeley.edu/chamacos/

Project Description

The Center for Children's Environmental Health Research at the University of California, Berkeley has successfully created a fully coordinated research program that addresses the unique environmental health needs of primarily Latino farmworker children living in an agricultural community. The investigators have focused their research on pesticide exposures, their potential health consequences, and community-based exposure prevention strategies. A strong community partnership and infrastructure has been developed with extensive outreach to constituent groups, service providers, and policy makers, and the investigators have received awards from both the University and the community. In addition, the investigators have leveraged Center resources to obtain additional funding for numerous other community and scientific projects. The core of the Center has been the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) project, conducted in collaboration with a coalition of community health care providers and agencies. CHAMACOS, which means 'small child' in Mexican Spanish, is a longitudinal birth cohort study of pregnant women and children living in the agricultural community of the Salinas Valley, Monterey County, California. The CHAMACOS cohort includes primarily low-income Mexican immigrant farmworkers and their families, and thus, provides a unique opportunity to examine prospectively the influence of prenatal and early childhood exposures encountered in an agricultural environment, such as to pesticides and bioaerosols, on the health of children. The investigators are following the CHAMACOS cohort into the school years to determine whether prenatal and childhood exposure are impacting their neurodevelopment, respiratory health, and somatic growth. Moreover, they are expanding the scope of the Center in three related and complementary directions: first, laboratory investigations are being conducted to understand the mechanisms of immuno- and neuro-toxicity of pesticides; second, exposure-related studies are being conducted to better understand the routes and pathways of pesticide exposure to children; and third, outreach is being extended to constituent groups within the immediate Salinas community and to similar populations in Monterey County, the state of California, and throughout the nation. These activities are accomplishing the Center's ultimate goal: to translate research findings into sustainable strategies to reduce pesticide and other environmental exposures to children, and thus reduce the incidence of environmentally related childhood disease.

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Project Highlights

Differences in susceptibility to pesticides

Center investigators recently published two papers (Furlong et al 2006; Holland et al 2006) on differences in susceptibility to pesticides based on age and PON1 genotype.  Center investigators found that some newborns may be 26 to 50 times more susceptible to exposure to certain organophosphate pesticides than other newborns, and 65 to 130 times more sensitive than some adults.  These findings are directly related to EPA rulemaking under the Food Quality Protection Act (FQPA) for organophosphate pesticides.  The Center has received two additional R01 level grants to extend PON1 genotyping and activity assessments for the entire cohort and newborns and examine the interaction of genotype and exposure on child neurodevelopment.

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Association of OP pesticides and neurodevelopment

Center investigators have found an association between maternal OP pesticide exposure during pregnancy and adverse neurodevelopment of her child.  Center investigators have published one paper (Young et al 2005) that demonstrates an association between in utero OP exposure and increased risk of abnormal reflexes in neonates.  Center investigators have also found that children who experienced higher OP exposure in utero also have poorer mental development at age 24 months, as assessed by the Bayley Scales of Infant Development.  These findings have been submitted for publication.  Center investigator findings on association of organophosphate pesticide exposure and neurodevelopment in children will directly relate to EPA rulemaking under FQPA for organophosphate pesticides.

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Association of DDT and neurodevelopment

Center investigator finding that maternal DDT levels during pregnancy are associated with poorer mental development of the child at age 24 months has had considerable impact (Eskenazi et al 2006).  This paper was published in June and coincided with announcements by international agencies (ie USAID, WHO) that they were changing global policies to encourage DDT use for malaria control in countries where the disease is endemic.  Dr. Eskenazi has spoken to WHO officials about these findings and was interviewed extensively in the press.  No previous studies had examined the relationship of neurodevelopment with DDT exposure. These results have since been replicated by other researchers in a different population (Ribas-Fito et al, submitted), indicating that further exposure and epidemiologic research is needed to monitor the balance of  risks and benefits of DDT use in malaria control.  Center investigators have a new RO1 grant pending that will extend DDT/DDE and PBDE measurements to 5 year old CHAMACOS children and allow us to examine the long-term effects and possible interaction of these exposures on neurodevelopment.

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