Air pollution in Delhi, India: It’s status and association with respiratory diseases

Abstract

The policymakers need research studies indicating the role of different pollutants with morbidity for polluted cities to install a strategic air quality management system. This study critically assessed the air pollution of Delhi for 2016–18 to found out the role of air pollutants in respiratory morbidity under the ICD-10, J00-J99. The critical assessment of Delhi air pollution was done using various approaches. The mean PM2.5 and PM10 concentrations during the measurement period exceeded both national and international standards by a wide margin. Time series charts indicated the interdependence of PM2.5 and PM10 and connection with hospital visits due to respiratory diseases. Violin plots showed that daily respiratory disease hospital visits increased during the winter and autumn seasons. The winter season was the worst from the city’s air pollution point of view, as revealed by frequency analyses. The single and multi-pollutant GAM models indicated that short-term exposure to PM10 and SO2 led to increased hospital visits due to respiratory diseases. Per 10 units increase in concentrations of PM10 brought the highest increase in hospital visits of 0.21% (RR: 1.00, 95% CI: 1.001, 1.002) at lag0-6 days. This study found the robust effect of SO2 persisted in Delhi from lag0 to lag4 days and lag01 to lag06 days for single and cumulative lag day effects, respectively. While every 10 μg m-3 increase of SO2 concentrations on the same day (lag0) led to 32.59% (RR: 1.33, 95% CI: 1.09, 1.61) rise of hospital visits, the cumulative concentration of lag0-1 led to 37.21% (RR: 1.37, 95% CI:1.11, 1.70) rise in hospital visits which further increased to even 83.33% (RR: 1.83, 95% CI:1.35, 2.49) rise at a lag0-6 cumulative concentration in Delhi. The role of SO2 in inducing respiratory diseases is worrying as India is now the largest anthropogenic SO2 emitter in the world.

Towards practical metal–oxygen batteries: general discussion

“…As a proof of concept if a physical quencher of singlet oxygen is present in the electrolyte, carbonate should not be formed. 3 Have you any experimental evidence in this direction? Xiangwen Gao responded: Thank you for this insightful comment.…”

“…The multiple oxidation state features also enhance the electric conductivity of the perovskites. The electric conduction relies on the B-O-B bonds and the B n+ /B (n+1)+ redox couple, according to the Zerner double exchange regime: 3 We did not measure the thickness of the discharge product. During the discharge product accumulation process, it will cover the active site gradually and thus leads to a discharge potential drop.…”

“…In cities, these can be sustainably higher due to pollution, considering the worst polluted cities as reported by the World Health Organisation: 2 NO x -175 ppb, PM 2.5 160 ppb, PM 10 450 ppb. For examples, Delhi has a SO 2 concentration of 15 ppb, 3 and indoor general volatile organic compound content in Chinese cities is at worst 960 ppb. 4 With a less polluted city (London) having values of NO x -29 ppb, PM 2.5 -9 ppb, PM 10 -18 ppb, SO 2 less than 1 ppb.…”

An empirical analysis of Delhi's air quality throughout different COVID-19 pandemic waves

“…The first wave (P1) of COVID-19 began in Delhi on March 4, 2020, with the discovery of the first COVID-19 infected patient, and reached its peak on November 11, 2020, with 8,593 daily infection cases. During the first wave of the COVID-19 pandemic, Lockdown procedures enhanced Delhi's and other Indian cities' air quality, but with its enormous population, India could not give up on the goal of rapid economic progress (Dutta and Jinsart, 2021c;Dutta and Jinsart, 2021d;Dutta and Jinsart, 2022). Following that, new infection cases fell precipitously, and by December 31, just 574 new infected COVID-19 cases had been recorded, signalling the end of the first wave.…”

Geographic information system-based mapping of air pollution & emergency room visits of patients for acute respiratory symptoms in Delhi, India (March 2018-February 2019)

“…The national capital of India, Delhi, is amongst one of the most-polluted cities of the world 1 , 2 and is facing major environmental challenge 3 . In Delhi, per 10 unit increase in the concentration of sulphur dioxide and particulate matter (PM) 10 increases respiratory disease-related hospital visits by 83 and 0.21 per cent, respectively, at a previous lag of 0-6 days 4 , 5 . Ambient air pollutant levels of PM 2.5 PM 10 , sulphur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), ozone (O 3 ) and carbon monoxide (CO) in Delhi have been reported to exceed Indian National Ambient Air Quality Standards 6 .…”