Community-Based Participatory Research and Gene-Environment Interaction Methodologies Addressing Environmental...

The "From Mother to Child Project" is a molecular epidemiological study that employs a community- based participatory research (CBPR) approach and gene-environment interaction research to address environmental justice in migrant and seasonal farmworker (MSF) women and children of Mexican origin home-based in Baytown and La Joya, Texas. This paper presents the background and rationale for the study and describes the study design and methodology. Preliminary data showed that MSF women and children in Texas have measurable levels of pesticides in their blood and urine, some of which were banned in the United States decades ago and are possible human carcinogens. Polymorphisms in genes involved in chemical detoxification and DNA repair have been associated with susceptibility to genetic damage and cancer development in populations exposed to environmental toxins. The "From Mother to Child Project" is testing three hypotheses: (1) MSF women and children who are occupationally exposed to pesticides are at higher risk for DNA damage than are non-exposed women and children. (2) Both, the extent of pesticide exposure and type of polymorphisms in chemical detoxification and DNA repair genes contribute to the extent of DNA damage observed in study participants. (3) The mutagenic potency levels measured in the organic compounds extracted from the urine and serum of study participants will correlate with the total concentrations of pesticides and with the measured DNA damage in study participants. The study will enroll 800 participants: 200 MSF mother-child pairs; 200 children (one per family) whose parents have never worked in agriculture, matched with the MSF children by ethnicity, age ± 2 years, gender, and city of residence; and these children's mothers. Personal interviews with the mothers are used to gather data for both mothers and children on sociodemographic characteristics; pesticide exposure at work and home; medical and reproductive history; dietary assessment, and lifestyle factors. Blood and urine samples are collected from each participant and analyzed for (1) organochlorine and organophosphate pesticide levels, (2) genetic polymorphisms of chemical detoxification and DNA repair genes, (3) DNA damage (chromosomal aberrations), and (4) the mutagenic potential of pesticides in the serum and urine. Recruitment and data collection in Baytown is near completion, and over one third of the target population for the La Joya study site.