Effect of Biomass Burning, Diwali Fireworks, and Polluted Fog Events on the Oxidative Potential of Fine Ambient Particulate Matter in Delhi, India

Abstract

We investigated the influence of biomass burning (BURN), Diwali fireworks, and fog events on the ambient fine particulate matter (PM 2.5 ) oxidative potential (OP) during the postmonsoon (PMON) and winter season in Delhi, India. The real-time hourly averaged OP (based on a dithiothreitol assay) and PM 2.5 chemical composition were measured intermittently from October 2019 to January 2020. The peak extrinsic OP (OP v : normalized by the volume of air) was observed during the winter fog (WFOG) (5.23 ± 4.6 nmol•min −1 •m −3 ), whereas the intrinsic OP (OP m ; normalized by the PM 2.5 mass) was the highest during the Diwali fireworkinfluenced period (29.4 ± 18.48 pmol•min −1 •μg −1 ). Source apportionment analysis using positive matrix factorization revealed that traffic + resuspended dust-related emissions (39%) and secondary sulfate + oxidized organic aerosols (38%) were driving the OP v during the PMON period, whereas BURN aerosols dominated (37%) the OP v during the WFOG period. Firework-related emissions became a significant contributor (∼32%) to the OP v during the Diwali period (4 day period from October 26 to 29), and its contribution peaked (72%) on the night of Diwali. Discerning the influence of seasonal and episodic sources on health-relevant properties of PM 2.5 , such as OP, could help better understand the causal relationships between PM 2.5 and health effects in India.

Measurement report: Oxidation potential of water-soluble aerosol components in the southern and northern of Beijing

“…Figure 2 shows the comparison of DTTv and DTTm values measured in this study with those measured in other regions of Asia during similar periods. It can be seen that the DTTv values measured in Beijing (Campbell et al, 2021;Oh et al, 2023;this study) were lower than that in Jinzhou, Tianjin, Yantai, and Shanghai in China, Lahore and Peshawar in Pakistan, and Delhi in India (Liu et al, 2018;Ahmad et al, 2021;Puthussery et al, 2022;Wu et al, 2022a), higher than that in Xi'an, Nanjing, Hangzhou, Guangzhou, and Shenzhen in China, and Gwangju in Korea (Wang et al, 2019;Wang et al, 2020b;Ma et al, 2021;Yu et al, 2022c;Oh et al, 2023;Xing et al, 2023), and comparable with that in Ningbo, China (Chen et al, 2022). Different from DTTv, the DTTm value measured in NCNT in Beijing was similar with that in Jinzhou, Tianjin, Yantai, Shanghai and Ningbo in China (Liu et al, 2018;Chen et al, 2022;Wu et al, 2022a), and higher than that in other regions.…”

Outdoor Health Risk of Atmospheric Particulate Matter at Night in Xi’an, Northwestern China

“…The oxidative potential (OP) of particulate matter manifests its capacity to utilize surrogates or antioxidants in acellular assays and is standardized by the volume of air (DTTv, nmol/min/m 3 ). , As shown in Figure a, the DTT activity of PM 10 and PM 2.5 was graded as follows: winter PM 10 was 1.30 nmol/min/m 3 (ranging 0.50–2.27 nmol/min/m 3 ) and PM 2.5 was 1.22 nmol/min/m 3 (ranging 0.41–2.26 nmol/min/m 3 ) and spring PM 10 was 0.72 nmol/min/m 3 (ranging 0.24–6.02 nmol/min/m 3 ) and PM 2.5 was 0.56 nmol/min/m 3 (ranging 0.23–1.02 nmol/min/m 3 ). During the seasonal comparison, the DTT activities were higher in winter than in spring owing to adverse winter weather conditions (meteorological conditions), increased primary emissions, and oxidative toxicity, e.g., coal burning for heating systems and increased splitting of semivolatile organic compounds (SVOCs) in the particulate phase. ,, Interestingly, it was likewise worth mentioning that the observed average DTTv activity of PM during 2021 in Xi’an (1.30 and 1.22 nmol/min/m 3 ) was significantly greater than in other places, such as Shanghai, China: 0.13; Beijing, China: 0.19; Atlanta, USA: 0.31, Hongkong: 0.56; however, remarkably lower than Delhi, India: 3.65; Lahore, Pakistan: 1.5; and Tianjin, China: 3.4 . The regional variations of DTTv activity in concerning locations are mainly associated to varied PM components by several accrued sources, leading to changes in the OP value (Figure S10).…”

Resolving Organic Aerosol Components Contributing to the Oxidative Potential of PM2.5 in the North China Plain

“…Both OP v and OP m have been used to discuss the redox capability of PM in the literature (Campbell et al, 2021;Puthussery et al, 2022;Q. Yu et al, 2022).…”