Validation of Indirect Pesticide Exposure Estimates

描述（由申请人提供）： 因为病因致癌暴露之间通常需要多年时间 以及随后癌症的发生，流行病学家经常必须使用 研究参与者历史暴露的间接估计值。早些时候 研究表明，有关作物和相关农药的历史数据 应用程序可以用来估计农业农药的概率 生活在田野附近的人的接触，但这项回顾性工作可以 无法确定附近的居民是否真的受到了辐射。但 一项前瞻性研究，收集环境和生物样本， 离农田不同距离的家庭将1）揭示 是否出现清晰的曝光梯度，作为与 字段，以及2）指示测量的 家庭成员农药暴露和基于记录的预测方法 暴露。如果随着距离的增加出现可预测的曝光梯度， 从现场，然后回顾性暴露估计可以进一步 来解释这个梯度。我们打算研究除草剂 阿特拉津作为玉米地附近居民农药暴露的标志 在伊利诺斯州，一些乡村住宅区靠近 玉米地，2）城镇和社区并列， 农业用地。为了确定具体地区和具体房屋，我们将 使用各种数据，包括：美国农业普查和 伊利诺伊州农业统计局，航空摄影和/或卫星 影像、GIS数据集、本地化普查数据（区块、区块组和普查 区域水平）和地形图。我们从50个家庭中的每一个家庭 报名时，我们将包括一名成人和一名4岁以下的儿童， 我们将获得尿液样本;我们还将获得房屋灰尘样本， 每个家庭的饮用水样本。调查问卷将收集信息 关于行为和住房特征可能会影响 参与者的农药剂量。这项研究将有助于揭示 基于记录的技术将有助于重建农药暴露 以及使用额外的与保险相关的变量是否会增加 暴露估计的精确度。

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.