Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills

Lumbini, in southern Nepal, is a UNESCO world heritage site of universal value as the birthplace of Buddha. Poor air quality in Lumbini and surrounding regions is a great concern for public health as well as for preservation, protection and promotion of Buddhist heritage and culture. We present...

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Main Authors: D. Rupakheti, B. Adhikary, P. S. Praveen, M. Rupakheti, S. Kang, K. S. Mahata, M. Naja, Q. Zhang, A. K. Panday, M. G. Lawrence
Format: Article
Language:English
Published: Copernicus Publications 2017-09-01
Series:Atmospheric Chemistry and Physics
Online Access:https://www.atmos-chem-phys.net/17/11041/2017/acp-17-11041-2017.pdf
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author D. Rupakheti
D. Rupakheti
B. Adhikary
P. S. Praveen
M. Rupakheti
M. Rupakheti
S. Kang
S. Kang
S. Kang
K. S. Mahata
M. Naja
Q. Zhang
Q. Zhang
A. K. Panday
M. G. Lawrence
author_facet D. Rupakheti
D. Rupakheti
B. Adhikary
P. S. Praveen
M. Rupakheti
M. Rupakheti
S. Kang
S. Kang
S. Kang
K. S. Mahata
M. Naja
Q. Zhang
Q. Zhang
A. K. Panday
M. G. Lawrence
author_sort D. Rupakheti
collection DOAJ
description Lumbini, in southern Nepal, is a UNESCO world heritage site of universal value as the birthplace of Buddha. Poor air quality in Lumbini and surrounding regions is a great concern for public health as well as for preservation, protection and promotion of Buddhist heritage and culture. We present here results from measurements of ambient concentrations of key air pollutants (PM, BC, CO, O<sub>3</sub>) in Lumbini, first of its kind for Lumbini, conducted during an intensive measurement period of 3 months (April–June 2013) in the pre-monsoon season. The measurements were carried out as a part of the international air pollution measurement campaign; SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley – Atmospheric Brown Clouds). The main objective of this work is to understand and document the level of air pollution, diurnal characteristics and influence of open burning on air quality in Lumbini. The hourly average concentrations during the entire measurement campaign ranged as follows: BC was 0.3–30.0 µg m<sup>−3</sup>, PM<sub>1</sub> was 3.6–197.6 µg m<sup>−3</sup>, PM<sub>2. 5</sub> was 6.1–272.2 µg m<sup>−3</sup>, PM<sub>10</sub> was 10.5–604.0 µg m<sup>−3</sup>, O<sub>3</sub> was 1.0–118.1 ppbv and CO was 125.0–1430.0 ppbv. These levels are comparable to other very heavily polluted sites in South Asia. Higher fraction of coarse-mode PM was found as compared to other nearby sites in the Indo-Gangetic Plain region. The ΔBC ∕ ΔCO ratio obtained in Lumbini indicated considerable contributions of emissions from both residential and transportation sectors. The 24 h average PM<sub>2. 5</sub> and PM<sub>10</sub> concentrations exceeded the WHO guideline very frequently (94 and 85 % of the sampled period, respectively), which implies significant health risks for the residents and visitors in the region. These air pollutants exhibited clear diurnal cycles with high values in the morning and evening. During the study period, the worst air pollution episodes were mainly due to agro-residue burning and regional forest fires combined with meteorological conditions conducive of pollution transport to Lumbini. Fossil fuel combustion also contributed significantly, accounting for more than half of the ambient BC concentration according to aerosol spectral light absorption coefficients obtained in Lumbini. WRF-STEM, a regional chemical transport model, was used to simulate the meteorology and the concentrations of pollutants to understand the pollutant transport pathways. The model estimated values were ∼ 1. 5 to 5 times lower than the observed concentrations for CO and PM<sub>10</sub>, respectively. Model-simulated regionally tagged CO tracers showed that the majority of CO came from the upwind region of Ganges Valley. Model performance needs significant improvement in simulating aerosols in the region. Given the high air pollution level, there is a clear and urgent need for setting up a network of long-term air quality monitoring stations in the greater Lumbini region.
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spelling doaj.art-5d4c58134f6249eb9de32db9186ca64c2022-12-22T02:47:25ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-09-0117110411106310.5194/acp-17-11041-2017Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothillsD. Rupakheti0D. Rupakheti1B. Adhikary2P. S. Praveen3M. Rupakheti4M. Rupakheti5S. Kang6S. Kang7S. Kang8K. S. Mahata9M. Naja10Q. Zhang11Q. Zhang12A. K. Panday13M. G. Lawrence14Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaInternational Centre for Integrated Mountain Development (ICIMOD), Kathmandu, NepalInternational Centre for Integrated Mountain Development (ICIMOD), Kathmandu, NepalInstitute for Advanced Sustainability Studies (IASS), Potsdam 14467, GermanyHimalayan Sustainability Institute (HIMSI), Kathmandu, NepalUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaState Key Laboratory of Cryospheric Science, Cold and Arid Regions Environmental and Engineering Research Institute (CAREERI), Lanzhou 730000, ChinaCenter for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaInstitute for Advanced Sustainability Studies (IASS), Potsdam 14467, GermanyAryabhatta Research Institute of Observational Sciences (ARIES), Nainital, IndiaKey Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, ChinaCenter for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaInternational Centre for Integrated Mountain Development (ICIMOD), Kathmandu, NepalInstitute for Advanced Sustainability Studies (IASS), Potsdam 14467, GermanyLumbini, in southern Nepal, is a UNESCO world heritage site of universal value as the birthplace of Buddha. Poor air quality in Lumbini and surrounding regions is a great concern for public health as well as for preservation, protection and promotion of Buddhist heritage and culture. We present here results from measurements of ambient concentrations of key air pollutants (PM, BC, CO, O<sub>3</sub>) in Lumbini, first of its kind for Lumbini, conducted during an intensive measurement period of 3 months (April–June 2013) in the pre-monsoon season. The measurements were carried out as a part of the international air pollution measurement campaign; SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley – Atmospheric Brown Clouds). The main objective of this work is to understand and document the level of air pollution, diurnal characteristics and influence of open burning on air quality in Lumbini. The hourly average concentrations during the entire measurement campaign ranged as follows: BC was 0.3–30.0 µg m<sup>−3</sup>, PM<sub>1</sub> was 3.6–197.6 µg m<sup>−3</sup>, PM<sub>2. 5</sub> was 6.1–272.2 µg m<sup>−3</sup>, PM<sub>10</sub> was 10.5–604.0 µg m<sup>−3</sup>, O<sub>3</sub> was 1.0–118.1 ppbv and CO was 125.0–1430.0 ppbv. These levels are comparable to other very heavily polluted sites in South Asia. Higher fraction of coarse-mode PM was found as compared to other nearby sites in the Indo-Gangetic Plain region. The ΔBC ∕ ΔCO ratio obtained in Lumbini indicated considerable contributions of emissions from both residential and transportation sectors. The 24 h average PM<sub>2. 5</sub> and PM<sub>10</sub> concentrations exceeded the WHO guideline very frequently (94 and 85 % of the sampled period, respectively), which implies significant health risks for the residents and visitors in the region. These air pollutants exhibited clear diurnal cycles with high values in the morning and evening. During the study period, the worst air pollution episodes were mainly due to agro-residue burning and regional forest fires combined with meteorological conditions conducive of pollution transport to Lumbini. Fossil fuel combustion also contributed significantly, accounting for more than half of the ambient BC concentration according to aerosol spectral light absorption coefficients obtained in Lumbini. WRF-STEM, a regional chemical transport model, was used to simulate the meteorology and the concentrations of pollutants to understand the pollutant transport pathways. The model estimated values were ∼ 1. 5 to 5 times lower than the observed concentrations for CO and PM<sub>10</sub>, respectively. Model-simulated regionally tagged CO tracers showed that the majority of CO came from the upwind region of Ganges Valley. Model performance needs significant improvement in simulating aerosols in the region. Given the high air pollution level, there is a clear and urgent need for setting up a network of long-term air quality monitoring stations in the greater Lumbini region.https://www.atmos-chem-phys.net/17/11041/2017/acp-17-11041-2017.pdf
spellingShingle D. Rupakheti
D. Rupakheti
B. Adhikary
P. S. Praveen
M. Rupakheti
M. Rupakheti
S. Kang
S. Kang
S. Kang
K. S. Mahata
M. Naja
Q. Zhang
Q. Zhang
A. K. Panday
M. G. Lawrence
Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills
Atmospheric Chemistry and Physics
title Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills
title_full Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills
title_fullStr Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills
title_full_unstemmed Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills
title_short Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills
title_sort pre monsoon air quality over lumbini a world heritage site along the himalayan foothills
url https://www.atmos-chem-phys.net/17/11041/2017/acp-17-11041-2017.pdf
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