||5R21CA094717-03 Interpret this number
||Research Triangle Institute
||Validation of Indirect Pesticide Exposure Estimates
DESCRIPTION (provided by applicant):
Because many years typically elapse between etiologic carcinogenic exposures
and the subsequent occurrence of cancer, epidemiologists often must use
indirect estimates of historical exposures for study participants. Earlier
work suggests that historical data on crops and associated pesticide
applications can be used to estimate the probability of agricultural pesticide
exposures among persons living near fields, but this retrospective work could
not ascertain whether nearby residents actually were exposed. However, a
prospective study that collects environmental and biological samples from
households at different distances from agricultural fields would 1) reveal
whether a clear exposure gradient occurs as a function of distance from the
fields, and 2) indicate whether there is a correspondence between measured
exposures and a records-based method for predicting household member pesticide
exposures. If a predictable exposure gradient occurs with increasing distance
from the fields, then retrospective exposure estimates could be further
refined to account for this gradient. We propose to study the herbicide
atrazine as a marker of pesticide exposure in persons living near corn fields
in Illinois in areas with 1) pockets of rural housing located in proximity to
cornfields, and 2) towns and communities that lie in juxtaposition to
agricultural lands. To identify specific areas and specific houses, we will
use a variety of data including: the U.S. Census of Agriculture and the
Illinois Agricultural Statistics Service, aerial photography and/or satellite
imagery, GIS data sets, localized census data (block, block group and census
tract levels), and topographic maps. From each of the 50 households that we
enroll, we will include one adult and one child younger than 4 years from whom
we will obtain a urine sample; we will also obtain a house dust sample and
drinking water sample from each home. A questionnaire will capture information
about behaviors and housing characteristics that might influence the
participants' pesticide dose. The proposed study will help reveal whether
records-based techniques will be useful for reconstructing pesticide exposures
and whether the use of additional exposure-related variables increases the
precision of the exposure estimates.
A GIS-based method for household recruitment in a prospective pesticide exposure study.
, Curry R.J.
, Hanchette C.L.
, Phillips M.J.
, Wilcosky T.C.
International journal of health geographics, 2008-04-30; 7, p. 18.