The Ag Center's interdisciplinary team of UC Davis researchers collaborates on studying challenging aspects of agriculture affecting health and safety. Currents areas of research and outreach include:

Farm Worker Family Health Cohort Study.
Principal Investigator: Marc B. Schenker, Department of Public Health Sciences, University of California, Davis, CA

Hired farm workers provide the majority of the workforce for California's labor-intensive agricultural sector, and they also suffer the greatest health burden. California's hired farm workers face increased risks of morbidity and mortality from respiratory disease, musculoskeletal problems, infectious diseases, stress-related mental health disorders and lifestyle-related diseases such as obesity. There has been very little research into the etiology of the poor health outcomes that occur disproportionately in this population. The overall goal of this proposed project is to continue with a longitudinal follow-up of a cohort of hired farm worker families in California that was established through funding from NIOSH and The California Endowment. We propose to conduct two follow-up assessments of the MICASA study cohort in Mendota, California to assess the incidence and prevalence of diseases in this population. These follow-up assessments will be conducted on the 420 families comprising our farm worker cohort in Mendota. Interviews will be conducted with all MICASA study participants (both the head of household and spouse) twice during the five-year study period. We will also conduct pulmonary function testing, measure vital signs and take anthropometric measurements at two time periods in the population.. Finally, the exposure assessment component will collect quantitative data on particulate exposure in thesis population. The specific aims of the study are to: 1) measure the incidence of respiratory symptoms and agricultural injuries and assess the independent association of agricultural exposures and lifestyle factors to respiratory symptoms, agricultural injuries, and musculoskeletal problems; 2) examine the prevalence and determinants of atopy, asthma and asthma symptoms; 3) determine levels of particulate matter exposures for tasks and crops commonly conducted by agricultural workers in our population; 4) examine incident respiratory symptoms and changes in pulmonary function over time and assess the relationship between predictors such as occupational factors with incident symptoms and changes in pulmonary function.. This approach allows us to address a wide range of factors affecting health including work, home environment, and personal health behaviors. This cohort is being established to improve understanding of important health risks and to provide a basis for the de sing of effective public health and clinical interventions, and ultimately to improve the health of this undeserved population.

Respiratory Health Exposures on Large California Dairies.
Principal Investigators: Deborah H. Bennett, Department of Public Health Sciences, and Frank M. Mitloehner, Department of Animal Science, University of California, Davis, CA

California ranks first in the USA for milk production. In the San Joaquin Valley, herd size is dramatically increasing (> 800 lactating cows/dairy). Indoor confinement barns are not used, but the dry, hot climate allows outdoor housing of cows in open sided free stalls or open dirt-floored corrals. The large operational size of the dairies and some management practices may pose a respiratory health hazard for workers. This cross-sectional study aims to define the concentrations of airborne pollutants highly associated with respiratory problems and study the respiratory health of the dairy workers compared to a control group of creamery employees and also to dairy workers under different management practices in a collaborator's study in Colorado. The main hypotheses are 1) exposure to elevated concentrations of airborne pollutants will result in increases respiratory symptoms and changes in pulmonary function over the work shift; 2) specific dairy tasks will be associated with different pollutant concentrations and 3) long-term exposure to elevated pollutants will result in increased prevalence of respiratory symptoms, reduced lung function, and more respiratory problems in dairies than in creamery workers.

California Dairy Environmental Health Research Initiative (Cal-Dehri) website:
http://cal-dehri.ucdavis.edu

Health Effects of Ambient Airborne Particles from the Sacramento/San Joaquin Valley.
Principal Investigator: Kent Pinkerton, Department of Anatomy, Physiology & Cell Biology, University of California, Davis, CA

The unique working environment of Californian farmers places them at increased risk for exposure to airborne particles. Dry farming techniques used in the Central Valley of California result in high levels of airborne particles produced by a variety of operation, including field preparation (plowing), rice stubble burning, and harvesting crops of tomatoes, grapes, and citrus fruits. Dairy operations in California also subject workers to a wide range of airborne particles arising from a diverse number of sources, both organic and inorganic. The size, composition, and distribution of particles generated by each of these activities are sufficiently different that they could produce unique health outcomes following inhalation. We will test this hypotheses by performing animal inhalation experiments at sites dominated by different types of agricultural particles. The primary objectives for Project 3 will be to (1) determine how variation in particle concentration, size, and composition in agricultural settings affect health outcomes in laboratory rats, (2) identify sources of fine and ultrafine particulate matter in farming and dairy settings in the Sacramento and San Joaquin Valleys and test their health effects through direct exposure studies using laboratory animals, and (3) examine the importance of season in each agricultural setting where particle size and composition are likely to be different due to level of activity and weather.

Rapid Assays for Human and Environmental Exposure Assessment.
Principal Investigators: Bruce Hammock, Department of Entomology and Cancer Research Center and Shirley Gee, Department of Entomology and Cancer Research Center, University of California, Davis, CA

The overall aim of this project is to provide rapid, sensitive and cost effective immunoassays that will provide high quality analytical data for use in exposure assessment, model development and mechanistic research. Developing technologies to improve the speed, sensitivity and robustness of existing immunoassays for biomarkers, particularly of pesticide exposure, comprises the first objective. By adapting assays to smaller volumes and to various existing automated platforms the throughput of the samples will be increased. Miniaturizing assays will mean that much less sample will need to be taken. For example, instead of milliliters of blood, assays may be conducted on blood obtained from a finger-prick, a technique more likely to be acceptable to future study participants. Sensitivity and robustness will be increases by applying labels that are detected more sensitively, such as lanthanide fluorophores and chemiluminescent reagents and by applying novel binding reagents such as phage displayed peptides. The second objective is to develop immunoassays for new analytes of both exposure and effect that have been identified as useful to other WCAHS investigators. We are studying the metabolites of the insecticides imidacloprid, thiomethoxam and fipronil as indicators of exposure to pesticides and they oxylipins leukotoxin and leukotoxin diol as indicators of an inflammatory effect. The third objective is to provide analytical support to other WCAHS investigators with existing pesticide immunoassays. In particular, we will determine the relative contribution from food, home environment or occupational environment to the total exposure to pyrethroid insecticides. We anticipate that the major impact of this research on public health will be the development of sensitive, rapid, cost effective analysis tools for biomarkers of the pesticides, permethrin, imidacloprid, thiomethoxam and fipronil and a more general marker of inflammation. These tools will be used in the studies in this Center to understand the contribution of various routes of pesticide exposure to farmworkers and their families and to study mechanisms of inflammation following exposure to air pollution from the Central Valley of California.

PILOT PROJECTS:

Health Implications of Airborne Agricultural Particles in the Central Nervous System.
Principal Investigator: Mai Ngo, Center for Health and the Environment, University of California, Davis, CA

The dry farming practices of California's Central Valley subject agricultural workers to high concentrations of airborne particles during field preparation, harvesting and packing of fruits and vegetables. The ability of inhaled ambient particles to induce inflammation in the central nervous system is of profound importance considering the role of inflammation in a number of neurological conditions including Parkinson's disease. Although Parkinson's disease is manifested late in life, initiation of pathogenic processes may be detected relatively shortly after exposure. This study proposes to resourcefully utilize archived brain tissue from studies previously conducted to assess the pulmonary effects of inhaled concentrated ambient particles from the agriculture setting to assess the ability of agricultural particles to alter neurological parameters reminiscent of Parkinson's disease.

Child Feeding Practices in Mexican-Americans: an early start in obesity prevention.
Principal Investigator: Lucia Kaiser, Department of Nutrition, University of California, Davis, CA

Among Mexican children aged 6-11 years old, 17 percent of girls and 26 percent of boys are overweight, and these numbers increase through adolescence and adulthood. Although dietary factors, low physical activity levels and genetic predisposition have been implicated as plausible contributors to the higher prevalence of overweight Mexican-American children, little is known about the development of eating habits. Strategies to combat the obesity epidemic will undoubtedly require attention to those risk factors that are modifiable and timely. The purpose of this study is to investigate the relationships between child-feeding practices, dietary intake and toddler growth in a Mexican population using a 6-month longitudinal design to capture child-feeding practices during an important dietary transition phase in toddlers. This original research will provide antecedent findings to further our understanding of childhood obesity in Mexican-American children as well as providing strategies for early prevention in a high-risk group.

Building a Foundation for Participatory Action Research with Agricultural Worker Communities; An Environmental Justice Perspective.
Principal Investigator: Jonathan London, Department of Human and Community Development, University of California, Davis, CA

Central Valley communities where agricultural workers and their families predominate are threatened by multiple sources of environmental pollution, including pesticide contamination of air and water, asthma-causing particulate matter, and leachate from hazardous waste facilities and disposal sites. Despite this concentration of risk, agricultural workers are rarely represented in public decision-making on the policies and practices that affect their lives. This proposed project seeks to address environmental injustices in the Central Valley by (1) conducting an inventory of existing research on the environmental health conditions of agricultural workers communities and of additional questions that members of these communities and their advocates want to research to answer, and (2) analyzing an innovative policy experiment underway through the California Department of Pesticide Regulation to engage agricultural worker communities and their advocates in developing an environmental justice action plan.

Collaborative Community Outreach Project in Parlier, CA.
Principal Investigator: Joyce Gutstein, Public Service Research Program, University of California, Davis, CA

The Collaborative Community Outreach Project focuses on air quality and agricultural health issues in Parlier, CA. The project links UC Davis entities (the JMIE Community Liaison Program, the Center for Health and Environment, and the Western Center for Agricultural Health and Safety) providing more effective community outreach. The project's purpose is to benefit agricultural workers and their families through the sharing of university research knowledge on air quality and its potential impact on human health. Investigators will collaborate with members of the community of Parlier and relevant partners in designing solutions to improve environmental, community and personal health. This approach offers a model for translational science for agricultural health and other topics, which goes beyond research and outreach to ensure community interest, learning and involvement.

Conference Support - Immigration Reform: Implications for Farm Worker Health and Safety.
Principal Investigator: Philip Martin, Department of Agriculture and Resource Economics, University of California, Davis, CA

Immigration reform may be the most significant policy change to affect farm workers health and safety in 2007, affecting the number, characteristics, employment and earnings, and health and health care benefits of farm workers. This conference aims to evaluate immigration reforms, bringing together policy makers with researchers and community leaders; we will work with the WCAHS to identify appropriate health researchers. The project's intended outcome is the development of a research agenda for the commissions charged with evaluating the effects of legalization, guest workers, as well as new interior enforcement efforts.

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