Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China

Traffic-related air pollutants (TRAPs) pose significant health risks in megacities, yet fixed monitoring sites often fail to capture their complexity. To characterize the TRAP concentrations which fixed sites cannot address, we employed a mobile platform to effectively capture real-time hyperlocal-s...

Full description

Bibliographic Details
Main Authors: Xiang, Sheng, Yu, Jiaojiao, Yu, Yu Ting, Zhao, Pengbo, Zheng, Tie, Yue, Jingsong, Yang, Yuanyuan, Liu, Haobing
Format: Article
Published: Multidisciplinary Digital Publishing Institute 2025
Online Access:https://hdl.handle.net/1721.1/158296
_version_ 1826192565103230976
author Xiang, Sheng
Yu, Jiaojiao
Yu, Yu Ting
Zhao, Pengbo
Zheng, Tie
Yue, Jingsong
Yang, Yuanyuan
Liu, Haobing
author_facet Xiang, Sheng
Yu, Jiaojiao
Yu, Yu Ting
Zhao, Pengbo
Zheng, Tie
Yue, Jingsong
Yang, Yuanyuan
Liu, Haobing
author_sort Xiang, Sheng
collection MIT
description Traffic-related air pollutants (TRAPs) pose significant health risks in megacities, yet fixed monitoring sites often fail to capture their complexity. To characterize the TRAP concentrations which fixed sites cannot address, we employed a mobile platform to effectively capture real-time hyperlocal-scale TRAP variations in Chengdu, China. A 17-day sampling campaign was conducted covering the National Holiday of China and collected ~1.2 × 105 1 Hz paired data. We measured particle number concentration (PNC), black carbon (BC), and nitrogen oxides (NOx) across urban and rural freeway environments to assess the impact of reduced heavy-duty diesel vehicles (HDDVs) during the holiday (i.e., holiday effect). No clear impact of wind direction on TRAP concentrations was found in this study. However, substantial differences (two times) were observed when comparing non-holiday to holiday campaigns. Spearman correlations (0.21–0.56) between TRAPs persistently exceeded Pearson correlations (0.14–0.41), indicating non-linear relationships and suggesting the necessity for data transformations (e.g., logarithms) in TRAP analysis. The comparison of the background subtracted TRAPs concentrations between non-holiday and holidays, revealing approximately a 50% reduction in TRAPs across microenvironments. Among the TRAPs, NOx emerged as a reliable indicator of HDDV emissions. The study provides insights into vehicle fleet composition impacts, paving the way for enhanced exposure assessment strategies.
first_indexed 2025-03-10T07:49:06Z
format Article
id mit-1721.1/158296
institution Massachusetts Institute of Technology
last_indexed 2025-03-10T07:49:06Z
publishDate 2025
publisher Multidisciplinary Digital Publishing Institute
record_format dspace
spelling mit-1721.1/1582962025-03-04T17:44:13Z Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China Xiang, Sheng Yu, Jiaojiao Yu, Yu Ting Zhao, Pengbo Zheng, Tie Yue, Jingsong Yang, Yuanyuan Liu, Haobing Traffic-related air pollutants (TRAPs) pose significant health risks in megacities, yet fixed monitoring sites often fail to capture their complexity. To characterize the TRAP concentrations which fixed sites cannot address, we employed a mobile platform to effectively capture real-time hyperlocal-scale TRAP variations in Chengdu, China. A 17-day sampling campaign was conducted covering the National Holiday of China and collected ~1.2 × 105 1 Hz paired data. We measured particle number concentration (PNC), black carbon (BC), and nitrogen oxides (NOx) across urban and rural freeway environments to assess the impact of reduced heavy-duty diesel vehicles (HDDVs) during the holiday (i.e., holiday effect). No clear impact of wind direction on TRAP concentrations was found in this study. However, substantial differences (two times) were observed when comparing non-holiday to holiday campaigns. Spearman correlations (0.21–0.56) between TRAPs persistently exceeded Pearson correlations (0.14–0.41), indicating non-linear relationships and suggesting the necessity for data transformations (e.g., logarithms) in TRAP analysis. The comparison of the background subtracted TRAPs concentrations between non-holiday and holidays, revealing approximately a 50% reduction in TRAPs across microenvironments. Among the TRAPs, NOx emerged as a reliable indicator of HDDV emissions. The study provides insights into vehicle fleet composition impacts, paving the way for enhanced exposure assessment strategies. 2025-03-04T17:44:11Z 2025-03-04T17:44:11Z 2025-02-02 2025-02-25T13:04:49Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/158296 Xiang, S.; Yu, J.; Yu, Y.T.; Zhao, P.; Zheng, T.; Yue, J.; Yang, Y.; Liu, H. Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China. Atmosphere 2025, 16, 171. PUBLISHER_CC http://dx.doi.org/10.3390/atmos16020171 Atmosphere Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ application/pdf Multidisciplinary Digital Publishing Institute Multidisciplinary Digital Publishing Institute
spellingShingle Xiang, Sheng
Yu, Jiaojiao
Yu, Yu Ting
Zhao, Pengbo
Zheng, Tie
Yue, Jingsong
Yang, Yuanyuan
Liu, Haobing
Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China
title Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China
title_full Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China
title_fullStr Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China
title_full_unstemmed Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China
title_short Exploring the Holiday Effect on Elevated Traffic-Related Air Pollution with Hyperlocal Measurements in Chengdu, China
title_sort exploring the holiday effect on elevated traffic related air pollution with hyperlocal measurements in chengdu china
url https://hdl.handle.net/1721.1/158296
work_keys_str_mv AT xiangsheng exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT yujiaojiao exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT yuyuting exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT zhaopengbo exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT zhengtie exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT yuejingsong exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT yangyuanyuan exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina
AT liuhaobing exploringtheholidayeffectonelevatedtrafficrelatedairpollutionwithhyperlocalmeasurementsinchengduchina