Abstract
In the U.S., there are currently 22.7 million people living with asthma with a large cost to society estimated
at $89 billion. Environmental exposures have been identified as playing a role in asthma etiology and lung
function growth and the relationship with air pollution exposure is well established in more urban areas. Pesticide
exposure has also been related to asthma and decline in lung function in workers. In the Center for the Health
Assessment of Mothers And Children Of Salinas (CHAMACOS) Study, a longitudinal study of Latino farmworker
families in Salinas California, we observed that early life exposure to several pesticides, as measured by
biomarkers or residential proximity to agricultural use, were associated with childhood asthma and poorer lung
function at age 7. It is unknown if these relationships persist into adulthood. Few studies have examined the
impact of exposure to mixtures of pollutants such as particulate matter and pesticides. Methylation of DNA from
nasal cells has been related to asthma and airway inflammation and there is evidence of differential methylation
with exposure to pollutants, suggesting a possible link between environmental exposures and respiratory health.
The long-term goal of our research is to identify modifiable factors related to respiratory health in a birth
cohort that has reached young adulthood. We will leverage the unique CHAMACOS prospective birth cohort
study to address these questions. Participants are currently 21 years of age and 500 participants still live near
the Salinas Valley, and 250 completed lung function testing at 7 years of age. Our objectives in this proposal are
to determine whether early life exposure to pesticides continue to impact their respiratory health in adulthood,
identify the relative importance of pesticide and air pollution exposures, periods of susceptibility (prenatal, early
life and childhood/adolescence), factors that modify these relationships and potential mechanisms involving the
methylation of nasal cells. We hypothesize that higher exposure to pesticides and air pollutants in early life will
result in poorer respiratory health and that DNA methylation will be a biomarker of these relationships. We will
conduct spirometry testing at 22y and estimate pesticide exposure using California’s unique Pesticide Use
Report data for the prenatal, early life (0-3y), childhood/adolescence (4-20y) and recent (previous year) periods.
We will estimate exposure to particulate matter air pollution by combining remote sensing and air monitoring
data. We will measure methylation in DNA collected from nasal swabs. We will assess whether associations
observed in the CHAMACOS cohort between pesticide exposure and respiratory health at 7y persist into early
adulthood and determine associations of exposure to a mixture of pesticides and particulate matter with
respiratory symptoms, asthma, allergy, and lung function. We will characterize associations of DNA methylation
with environmental exposures and respiratory health. In this study, we expect to identify the most important
exposures and periods of exposure related to adverse respiratory health. Our findings will help inform future
policies related to pesticide use and air quality designed to protect respiratory health.
