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Evaluation of new methods for estimating exposure to traffic-related pollution and early health effects for large population epidemiological studies.

机译：对大量人群流行病学研究中估计与交通有关的污染和早期健康影响的估计新方法的评估。

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摘要

Objective: There is emerging evidence that local traffic-related pollution (TRP) has adverse health effects that are independent of regional pollution effects. Current methods to assess TRP exposure have limitations that may account for uncertainty and inconsistency in the observed traffic-related health effects. New methods are needed to assess TRP exposure in different microenvironments and to assess early biological effects of these exposures in population based studies of air pollution. I evaluated new tools that can be used to assess time and activity and also evaluated the impact on novel biological markers of exposure to TRP and biomarkers of early biological effects.;Specifically the objectives of my research were: 1) to evaluate the accuracy of a time-resolved step counter in children and the duration of consecutive zero step count minutes that indicated non-wear time periods 2) evaluate the ability of a GPS data logger to assess location of children during usual activity and 3) to assess feasibility of collecting urine samples at school and to evaluate urinary biomarkers of exposure and early effect of traffic-related air pollution. The overall goal of my research was to identify methods that could greatly improve exposure assessments of TRP by providing an integrated metric of dose that could be used to strengthen studies investigating the relationship between TRP exposure and health affects.;Methods: To evaluate these tools, I conducted two studies. In the first study, a new time-resolved step counter, the SportBrain, was evaluated for accuracy. Seventeen children walked or ran on a treadmill at 2, 3, 4 and 5 miles/hour and walked around a track while wearing the SportBrain and Digiwalker SW-701 pedometers. We compared percent error in step counts for the two pedometers relative to observer counts. A sub-sample wore an accelerometer and SportBrain pedometer during up to 5 days of usual activity. In the second study, up to five urine samples per child were collected before and after a school field trip with bus travel on a busy highway from fifteen 9-10 year olds recruited from two classrooms in a low pollution region of Los Angeles. Samples were analyzed for biomarkers of exposure (ten polycyclic aromatic hydrocarbon metabolites and 1-aminopyrene) and of effect (Clara cell protein 16 and 8-iso-PGF2alpha, a major F2-isoprostane). Four days of data from 17 children wearing GPS loggers recording every 15 seconds were evaluated for completeness by time of day during weekend and weekdays and for accuracy during nighttime at home. Percentage of possible GPS recorded points and of 5-minute intervals with at least one recorded location were examined.;Results: The SportBrain pedometer performed with acceptable accuracy at all evaluated treadmill speeds and during self-paced walking, recording steps within an average of 4% of observed step counts. During normal wear only 1% of zero count periods were less than 60 minutes. 60% of participants collected all five urine samples. There was no statistically significant difference between the pre- and post-trip measurements of any biomarker. There was a high proportion of missing GPS location data. Mean percentage of total possible 15-second interval locations recorded daily was less than 30%. Across participants, the GPS loggers recorded 1% to 47% of total possible location points on weekends and 1% to 55% on weekdays. More complete data were measured during travel to school (average 90%). During nighttime (12am-6am), on average, location was recorded for less than 25% of 5-minute intervals and accuracy was poor. Urine collection was feasible in a school setting. 60% of participants collected all urine five samples. However, there was no statistically significant difference between the pre- and post-trip measurements of any biomarker.;Conclusion: The SportBrain iStep X1 pedometer provides a valid measure of step counts in short averaging times useful for assessing patterns of physical activity in population studies and periods of non-wear. Collecting urine samples from children at school was feasible, but traffic effects were not detected after exposure in this small population sample. The large proportion of missing data, which varied by location, limits the usefulness of GPS logging instruments for population studies. They have potential utility for assessing on-road travel time and route.
机译：目的：越来越多的证据表明，与交通相关的局部污染（TRP）对健康的不利影响与区域污染的影响无关。当前评估TRP暴露的方法存在局限性，可能会限制观察到的与交通有关的健康影响的不确定性和不一致性。需要新的方法来评估不同微环境中的TRP暴露，并在基于人群的空气污染研究中评估这些暴露的早期生物学效应。我评估了可用于评估时间和活动的新工具，还评估了暴露于TRP的新型生物标志物和早期生物效应对生物标志物的影响。具体来说，我的研究目标是：1）评估a的准确性儿童时间分辨的步数计数器以及连续零步计数分钟的持续时间，表示无穿戴时间段2）评估GPS数据记录器评估正常活动期间儿童位置的能力，以及3）评估收集尿液的可行性在学校取样并评估尿液生物标志物的暴露和与交通有关的空气污染的早期影响。我研究的总体目标是通过提供可用于加强研究TRP暴露与健康影响之间关系的剂量的综合指标，确定可大大改善TRP暴露评估的方法。方法：要评估这些工具，我进行了两项研究。在第一个研究中，评估了一个新的时间分辨步数计数器SportBrain的准确性。十七名儿童戴着SportBrain和Digiwalker SW-701计步器，以每小时2、3、4和5英里的速度在跑步机上行走或奔跑，并在跑道上行走。我们比较了两个计步器相对于观察者计数的步数误差百分比。子样本在长达5天的日常活动中都佩戴了加速度计和SportBrain计步器。在第二项研究中，在一次学校实地考察之前和之后，在洛杉矶一个低污染地区的两个教室招募的15名9-10岁的年轻人在繁忙的高速公路上乘坐公共汽车旅行，每个孩子最多收集了五个尿液样本。分析样品的生物标志物的暴露（十种多环芳烃代谢物和1-氨基py）和效果（Clara细胞蛋白16和8-iso-PGF2alpha，一种主要的F2-异前列腺素）。来自17个戴着GPS记录器的儿童每15秒记录一次的四天数据在周末和工作日的一天中的时间进行完整性评估，并在家中夜间进行准确性评估。检查了可能的GPS记录点的百分比以及至少有一个记录位置的5分钟间隔的百分比。结果：SportBrain计步器在所有评估的跑步机速度和自定速度的步行过程中均以可接受的精度执行，平均记录了4步观察到的步数的百分比。在正常穿着期间，零计数期间中只有1％的时间少于60分钟。 60％的参与者收集了所有五个尿液样本。在任何生物标记物的旅行前和旅行后测量之间没有统计学上的显着差异。丢失GPS定位数据的比例很高。每天记录的可能的15秒间隔位置的平均百分比小于30％。在参与者中，GPS记录器在周末记录了可能的总位置点的1％至47％，在工作日记录了1％至55％的位置。在上学期间测量了更完整的数据（平均90％）。在夜间（上午12点至凌晨6点），平均而言，记录不到5分钟间隔的25％的位置，并且准确性很差。在学校环境中收集尿液是可行的。 60％的参与者收集了全部五个尿样。但是，任何生物标志物的出行前和出行后测量之间没有统计学上的显着差异。结论：SportBrain iStep X1计步器可在较短的平均时间内提供有效的步数测量，可用于评估人群研究中的身体活动模式和不穿衣服的时期。从学校儿童收集尿液样本是可行的，但在这个小人群样本中暴露后未检测到交通影响。丢失数据的很大一部分（随位置而异）限制了GPS测井仪器在人口研究中的实用性。它们对于评估公路旅行时间和路线具有潜在的实用性。

著录项

  • 作者

    Dueker, Donna Carmel.;

  • 作者单位

    University of Southern California.;

  • 授予单位 University of Southern California.;
  • 学科 Health Sciences Epidemiology.;Health Sciences Public Health.;Atmospheric Sciences.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 143 p.
  • 总页数 143
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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