Utility of outdoor central site monitoring in assessing exposure of school children to ultrafine particles.
Utility of outdoor central site monitoring in assessing exposure of school children to ultrafine particles.
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室外中心站点监测在评估学童超细颗粒暴露情况中的效用。
DOI：
10.1016/j.scitotenv.2022.160162
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
L. Morawska
中科院分区：
文献类型：
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作者：
Basant Pradhan;R. Jayaratne;Helen Thompson;G. Buonanno;M. Mazaheri;M. Nyarku;Wei Wei;M. Pereira;J. Cyrys;A. Peters;L. Morawska
调查每日颗粒物暴露与健康影响之间关系的流行病学研究通常基于位于城市背景中的单个监测点。在流行病学时间序列研究中使用中心点的做法是基于感兴趣区域内颗粒物空间变异性低的前提，因此中心点足以监测接触情况。对于通常受到监测和监管的较大颗粒物（PM2.5、PM10）来说，这在很大程度上是正确的。然而，超细颗粒物（UFP），在城市中主要来源于交通，分布是不均匀的。随着提高超微粒子流行病学的压力越来越大，一个重要的问题是，中央现场监测是否代表社区暴露于这种尺寸的颗粒物;解决这个问题是本文的目的。为了实现这一目标，我们测量了个人暴露于UFP，表示为粒子数浓度（PNC），使用飞利浦Aerasense Nanotracers（NT）进行的参与者的研究，和凝聚粒子计数器（CPC）或扫描流动粒子粒度仪（SMPS）在中央固定站点监测站。测量工作在布里斯班（澳大利亚）、卡西诺（意大利）和阿克拉（加纳）的三个地点进行。然后，我们使用配对测试来比较平均个人和平均固定站点PNC测量在相同的24小时，每小时，期间。我们发现，在所有三个地点，24小时平均固定地点PNC是没有什么不同的个人PNC，平均在研究期间和所有参与者。然而，相应的每小时平均值在一天中的某些时间有显著差异。这些时间通常是在通勤和在家做饭和吃饭时花费的。我们对在布里斯班获得的数据进行的分析表明，最大的个人暴露发生在家庭微环境中的早餐和晚餐时间。个人接触PNC的主要来源是家庭微环境。我们的结论是，24小时平均PNC从中心网站可以用来估计24小时平均个人暴露的社区。然而，中心站点的每小时平均PNC不能一致地用于估计每小时平均个人暴露，主要是因为它们受到非常不同的来源的影响。
Epidemiological studies investigating the association between daily particle exposure and health effects are frequently based on a single monitoring site located in an urban background. Using a central site in epidemiological time-series studies has been established based on the premises of low spatial variability of particles within the areas of interest and hence the adequacy of the central sites to monitor the exposure. This is true to a large extent in relation to larger particles (PM2.5, PM10) that are typically monitored and regulated. However, the distribution of ultrafine particles (UFP), which in cities predominantly originate from traffic, is heterogeneous. With increasing pressure to improve the epidemiology of UFP, an important question to ask is, whether central site monitoring is representative of community exposure to this size fraction of particulate matter; addressing this question is the aim of this paper. To achieve this aim, we measured personal exposure to UFP, expressed as particle number concentration (PNC), using Philips Aerasense Nanotracers (NT) carried by the participants of the study, and condensation particle counters (CPC) or scanning mobility particle sizers (SMPS) at central fixed-site monitoring stations. The measurements were conducted at three locations in Brisbane (Australia), Cassino (Italy) and Accra (Ghana). We then used pairedt-tests to compare the average personal and average fixed-site PNC measured over the same 24-h, and hourly, periods. We found that, at all three locations, the 24-h average fixed-site PNC was no different to the personal PNC, when averaged over the study period and all the participants. However, the corresponding hourly averages were significantly different at certain times of the day. These were generally times spent commuting and during cooking and eating at home. Our analysis of the data obtained in Brisbane, showed that maximum personal exposure occurred in the home microenvironment during morning breakfast and evening dinner time. The main source of PNC for personal exposure was from the home-microenvironment. We conclude that the 24-h average PNC from the central-site can be used to estimate the 24-h average personal exposure for a community. However, the hourly average PNC from the central site cannot consistently be used to estimate hourly average personal exposure, mainly because they are affected by very different sources.