Identifying Hot Spots of Air Pollution Through Precipitation Chemistry Measurements in South Asia
U.C. Kulshrestha1, *, C. Di Marco2, E. Nemitz2, S.P. Nissanka3, Z. Ahmed4, A. Shaira4, R. Ramesh5, R. Purvaja5, D. Ganguly5, S. K. Sharma6, M. Rahman7, D. Tshering8, A. Lakhani9, M. Naza10, B.R. Gurjar11, N. Nigam12, and M. A. Sutton2
Emissions from rapidly increasing industrial and urban activities are the major cause of air pollution. Recently, nitrogen air pollution and its influence on precipitation chemistry, human health and environment have been the subjects of concerns of researchers. Ammonium aerosols, which mostly exist in fine mode, are scavenged by rain affecting air quality, rain chemistry, as well as soils, vegetation and buildings following their wet deposition onto surfaces. This study has been a part of UKRI GCRF South Asian Nitrogen Hub and reports pH and rain chemistry at a number of sites across South Asia, viz. DTG, Peradeniya (Sri Lanka), MAP (Maldives), KU, Dhulikhel (Nepal), BSMRAU, Dhaka (Bangladesh) and BRRI, Rangpur (Bangladesh), SC, Kanglung (Bhutan) and NCSCM, Chennai, LP Lakshadweep, DEI Agra, ARIES Nainital, IIT Roorkee, IMD New Delhi (India). The samples of rainwater were collected on event basis during 2022-23 using a manual wet collector. Samples were preserved with thymol for avoiding any biological decay. Chemical analysis for ionic components was carried out by using an ion chromatograph. Data selection and analysis were performed by using standard QA/QC practices. pH showed a large variation ranging from 2.94 at BSMRAU Dhaka to 9.40 at IMD New Delhi indicating a wide range of sources of influence in the region. Similarly, a large variation was noticed for Cl-, NO3-, nss-SO42-, NH4+, Na+, nss K+, nss Ca2+ and nss Mg2+. Detailed results will be discussed during the conference.
1 School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
2 UK Centre for Ecology & Hydrology, Edinburgh, UK
3 University of Peradeniya, Sri Lanka
4 Research Development Office, Maldives National University, Male, Maldives
5 National Centre for Sustainable Coastal Management, Chennai, India
6 Aquatic Ecology Center, Kathmandu University, Dhulikhel, Nepal
7 Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh
8 Sherubtse College, Royal University of Bhutan, Kanglung, Bhutan
9 Dayalbagh Educational Institute, Agra, India
10 Aryabhatta Research Institute of Observational Sciences, Nainital, India
11 Indian Institute of Technology, Roorkee, India
12 Indian Meteorological Department, New Delhi, India
* Corresponding Author: umeshkulshrestha@gmail.com