Division of Pediatric Pulmonary, Department of Pediatrics, Columbia University, Vagelos College of Physicians and Surgeons , 3959 Broadway CHC 7-750, New York, NY 10032, United States.
Columbia University, Vagelos College of Physicians and Sugeons, 630 W. 168th Stree, New York, NY 10032, United States.
Environ Pollut. 2023 Feb 15;319:120991. doi: 10.1016/j.envpol.2022.120991. Epub 2022 Dec 31.
Although real-time personal exposure monitoring devices have the ability to capture a wealth of data regarding fluctuations in pollutant levels, only a few studies have defined 'peaks' in black carbon (BC) exposure utilizing high-resolution data. Furthermore, studies to assess and characterize various features of peak exposure are very limited especially among children. A better understanding of characteristics of BC peak exposure would improve our understanding of health risks associated with BC. By capturing personal BC exposure at 5-min intervals using a real-time monitor during 24-hr monitoring periods among children in New York City (NYC), we defined 'peak characteristics' in 4 different ways across three major microenvironments (school vs. commute vs. home): 1) mean concentrations of BC across the 3 microenvironments, 2) 'peak duration' or time spent above the peak threshold (i.e., ≥1.5 μg/m), 3) 'peak intensity' or the rate of exposure, defined as time spent above the threshold within each microenvironment divided by the total time spent in the microenvironment and 4) a novel metric of 'peak variability', defined as frequency of peaks (i.e., data points with +50% and -50% changes compared to the preceding and the subsequent data points), divided by the total time spent in the microenvironment. While peak duration was greatest at home, the intensity of peak exposure was greatest during commute hours, despite the short time spent in commute (p < 0.05). Peak variability was highest during commute, yet lowest in home environments (p < 0.05), particularly during non-sleeping hours. Children residing in a high-density urban setting spent on average, 5.4 hr per day above our peak threshold (≥1.5 μg/m) in their everyday environments. Policies that limit children's exposure during high traffic periods and improved efforts to increase the number of vehicles using clean air technology could reduce the intensity of peaks and peak variability in children's BC exposure.
尽管实时个人暴露监测设备有能力捕捉大量有关污染物水平波动的数据，但只有少数研究利用高分辨率数据定义了黑碳 (BC) 暴露的“峰值”。此外，评估和描述峰值暴露的各种特征的研究非常有限，尤其是在儿童中。更好地了解 BC 峰值暴露的特征将有助于我们了解与 BC 相关的健康风险。通过在纽约市 (NYC) 的儿童 24 小时监测期间使用实时监测器以 5 分钟的间隔捕获个人 BC 暴露情况，我们在三个主要微环境（学校、通勤和家庭）中以 4 种不同方式定义了“峰值特征”：1) 3 个微环境中 BC 的平均浓度，2)“峰值持续时间”或高于峰值阈值（即≥1.5μg/m）的时间，3)“峰值强度”或暴露率，定义为在每个微环境中高于阈值的时间除以在微环境中花费的总时间，以及 4)一个新的“峰值可变性”指标，定义为峰的频率（即与前一个和后一个数据点相比数据点变化为+50%和-50%）除以在微环境中花费的总时间。尽管在家中时峰值持续时间最长，但在通勤时间内峰值暴露强度最大，尽管通勤时间很短 (p < 0.05)。峰值可变性在通勤时最高，但在家中环境中最低 (p < 0.05)，尤其是在非睡眠时间。居住在高密度城市环境中的儿童平均每天有 5.4 小时以上处于我们的峰值阈值（≥1.5μg/m）以上，处于日常环境中。限制儿童在交通高峰期暴露的政策以及增加使用清洁空气技术的车辆数量的努力可以降低儿童 BC 暴露的峰值强度和峰值可变性。
