Does NHANES underestimate true population-based exposures to pesticides? Exploring bias in NHANES human biomonitoring data.

摘要/摘要 人体生物监测(HBM)-对化学物质、其反应产物或代谢产物的测量 生物样本--是一种暴露评估技术，通常被认为是暴露的“黄金标准” 评估。美国利用国家健康和营养检查调查(NHANES)作为一种工具 为其国家HBM计划收集样本。NHANES数据采集在移动考试中的应用 中心(MEC)，包含移动实验室的大型拖车。计划数据收集的站点位置 包括季节性天气模式和MEC单元运输困难等考虑因素。因为 MEC部队不能轻易通过冰雪补丁的困难道路，后勤需要抽样 在冬季天气经常恶劣的地区，出现在较温暖的月份(即春季和夏季)，而 更温和的地区可以在较凉爽的月份(即冬季和秋季)进行采样。有鉴于此，NHANES 可能随季节变化的数据可能会受到时间和空间偏差的影响。这种潜在的偏见可能会在 反过来，导致对人口暴露和健康数据的不准确解释。我们将评估任何偏见在 使用两个特定目标的NHANES季节性化学品的HBM数据。1)开展国家级和季节性工作 尿液化学标志物季节性和非季节性在NHANES循环中的分布评价 1999-2016年，使用NCHS研究数据中心，允许访问受限的地理编码和采样日期。 2)将NHANES国家水平的尿中农药代谢物数据与较小规模的生物监测研究进行比较 在美国不同的州，在不同的季节进行。这项研究可以提供信息，使 疾控中心重新考虑他们的抽样物流，以更好地代表季节性和地区性变化，或者将使我们能够 以量化NHANES低估美国人口暴露的程度。

SUMMARY/ABSTRACT Human biomonitoring (HBM) – the measurement of a chemical, its reaction product, or metabolite in biosamples – is an exposure assessment technique that is often considered the “gold standard” in exposure assessment. The US uses the National Health and Nutrition Examination Survey (NHANES) as a vehicle for sample collection for its national HBM program. NHANES data collection occurs in Mobile Examination Centers (MEC), large trailers containing a mobile laboratory. Scheduling site locations for data collection includes considerations such as seasonal weather patterns and difficulties with MEC unit transit. Because MEC units cannot easily traverse difficult roadways with snow and ice patching, logistics require that sampling in areas often hit with harsh winter weather occur during the warmer months (i.e., spring and summer) whereas more temperate locations can be sampled in cooler months (i.e., winter and autumn). Given this, NHANES data that may vary by season could be subject to both temporal and spatial bias. This potential bias could, in turn, lead to inaccurate interpretations of population exposure and health data. We will evaluate any bias in HBM data of seasonal chemicals from NHANES using two specific aims. 1) Conduct state-level and seasonal evaluations of distributions of seasonal and non-seasonal chemical urinary biomarkers in NHANES Cycles 1999-2016 using the NCHS Research Data Center allowing access to restricted geocodes and sampling dates. 2) Compare NHANES state-level urinary pesticide metabolite data to smaller-scale biomonitoring studies conducted in different US states during different seasons. This study could provide information that will enable CDC to reconsider their sampling logistics to better represent seasonal and regional variations or will enable us to quantify the extent to which NHANES underestimates US population exposures.