“The Future
of Longitudinal Studies:
What we know; What we don’t know; What we need to
know”
The Reciprocal
Relation Between Studies Of Health/Normality And Illness/Psychopathology
Chaired by Stephen Hinshaw, University of California, Berkeley
Friday, March 21, 2003
Brenda Eskenazi
"CHAMACOS: A Longitudinal Birth Cohort Study Of Children’s
Development: Lessons from the fields"
University of California, Berkeley
The Center at the University of California, Berkeley,
known as CHAMACOS (Center for the Health Assessment of Mothers and
Children of Salinas) is a community-university partnership studying
pesticide and allergen exposures to pregnant women and their children,
and the potential effects of these exposures on growth, neurodevelopment,
and respiratory disease. Although virtually nothing is known about
the effect of pesticide exposure on human development, such exposure
(organophosphate exposure) in animals has been linked to harmful
neurodevelopmental effects, including decreased balance, poorer
depth perception, and deficits in spatial memory.
A cohort of six hundred pregnant women from the Salinas area were
followed through the time their children were two years old (a high
percentage of the sample continues to be followed). Sample characteristics
included the following: mean age of mothers, 25 years old; 88% spoke
Spanish (mostly unilingual); 40% worked in agriculture during pregnancy;
74% had another agriculture worker in house; 85% were born in Mexico;
96% were living at or below the poverty line; 44% had a sixth grade
education or less; 50% endorsed symptoms of clinical depression
on the CES-D (when the child was 12 months); 46% reported having
0 or 1 close friends/relatives to talk to; 17% of fathers were not
living at home; 51% of families did not have blocks or stacking
toys (when the child was 12 months); and 46% had pesticide stored
in the home. Pesticide levels in this sample of women were higher
than in the general population.
Among the multitude of measures collected, neurodevelopment test
batteries were given to the neonate, and then again at age six months,
twelve months, and twenty-four months. (Data collection for this
study is underway, and results will be forthcoming at a later time.)
One of the problems encountered in doing this research was the fact
that few tests are available for very young children, and even fewer
tests have been standardized in Spanish. There also are few tests
for low literacy populations. Although the challenges of collecting
longitudinal data may be greatest in minority or impoverished communities,
these communities are most at risk and must be studied. This research
underscores the importance of studying factors in both the immediate
environment (e.g., genes, nutrition) and the larger environment
(e.g., violence, poverty, acculturation).
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