TY - JOUR
T1 - Real-Time Measurements of PM2.5Oxidative Potential Using a Dithiothreitol Assay in Delhi, India
AU - Puthussery, Joseph V.
AU - Singh, Atinderpal
AU - Rai, Pragati
AU - Bhattu, Deepika
AU - Kumar, Varun
AU - Vats, Pawan
AU - Furger, Markus
AU - Rastogi, Neeraj
AU - Slowik, Jay G.
AU - Ganguly, Dilip
AU - Prevot, Andre S.H.
AU - Tripathi, Sachchida Nand
AU - Verma, Vishal
N1 - Funding Information:
This work was supported by SNSF Grants 200021-169787 SAOPSOAG, 200021-162448, and IZLCZ2-169986 HAZECHINA. JVP and ROS sampling was supported by V.V.'s startup fund by the Department of Civil and Environmental Engineering of the University of Illinois at Urbana-Champaign. S.N.T. was financially supported by the Department of Biotechnology (DBT), Government of India, under Grant BT/IN/UK/APHH/41/KB/2016-17 and by the Central Pollution Control Board (CPCB), Government of India under Grant AQM/Source apportionment EPC Project/2017. S.N.T. gratefully acknowledges their support that has helped in the conducting of this research. Additionally, the authors also thank Jay Dave (Physical Research Laboratory) for his contribution in the data collection during the field campaign.
Funding Information:
This work was supported by SNSF Grants 200021_169787 SAOPSOAG, 200021_162448, and IZLCZ2_169986 HAZECHINA. JVP and ROS sampling was supported by V.V.’s startup fund by the Department of Civil and Environmental Engineering of the University of Illinois at Urbana-Champaign. S.N.T. was financially supported by the Department of Biotechnology (DBT), Government of India, under Grant BT/IN/UK/APHH/41/KB/2016-17 and by the Central Pollution Control Board (CPCB), Government of India, under Grant AQM/Source apportionment EPC Project/2017. S.N.T. gratefully acknowledges their support that has helped in the conducting of this research. Additionally, the authors also thank Jay Dave (Physical Research Laboratory) for his contribution in the data collection during the field campaign.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/7/14
Y1 - 2020/7/14
N2 - The oxidative potential (OP) of ambient particulate matter (PM) is a metric commonly used to link the aerosol exposure to its adverse health effects. In this study, we report the first-ever real-time measurements of ambient PM2.5 OP based on a dithiothreitol (DTT) assay in Delhi, during a late winter season (February 2019). The chemical composition of PM was also measured using various collocated online instruments to identify the chemical components driving the PM2.5 OP. The hourly averaged OP during the entire campaign ranged from 0.49 to 3.60 nmol min-1 m-3, with an average value of 1.57 ± 0.7 nmol min-1 m-3. The secondary organic aerosols appear to be the major driver for the variation in the intrinsic OP of PM2.5. Although the average PM1 mass concentration at Delhi was 13 times the average PM2.5 mass concentration reported in Illinois, USA, in a similar study, it was not accompanied by a proportionate increase in the OP (the average volume-normalized DTT activity of PM2.5 was only 5 times that reported in Illinois). These findings reveal substantial spatial heterogeneity in the redox properties of PM and highlight the importance of determining the PM chemical composition along with its mass concentrations for predicting the overall health impacts associated with aerosol exposure.
AB - The oxidative potential (OP) of ambient particulate matter (PM) is a metric commonly used to link the aerosol exposure to its adverse health effects. In this study, we report the first-ever real-time measurements of ambient PM2.5 OP based on a dithiothreitol (DTT) assay in Delhi, during a late winter season (February 2019). The chemical composition of PM was also measured using various collocated online instruments to identify the chemical components driving the PM2.5 OP. The hourly averaged OP during the entire campaign ranged from 0.49 to 3.60 nmol min-1 m-3, with an average value of 1.57 ± 0.7 nmol min-1 m-3. The secondary organic aerosols appear to be the major driver for the variation in the intrinsic OP of PM2.5. Although the average PM1 mass concentration at Delhi was 13 times the average PM2.5 mass concentration reported in Illinois, USA, in a similar study, it was not accompanied by a proportionate increase in the OP (the average volume-normalized DTT activity of PM2.5 was only 5 times that reported in Illinois). These findings reveal substantial spatial heterogeneity in the redox properties of PM and highlight the importance of determining the PM chemical composition along with its mass concentrations for predicting the overall health impacts associated with aerosol exposure.
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U2 - 10.1021/acs.estlett.0c00342
DO - 10.1021/acs.estlett.0c00342
M3 - Article
AN - SCOPUS:85087398644
SN - 2328-8930
VL - 7
SP - 504
EP - 510
JO - Environmental Science and Technology Letters
JF - Environmental Science and Technology Letters
IS - 7
ER -