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Li X, Zhang R, Tripathee L, Yu F, Guo J, Yang W, Guo J, Kang S, Cao J. Characteristics, sources, and health risk assessment of atmospheric particulate mercury in Guanzhong Basin. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123071. [PMID: 38070642 DOI: 10.1016/j.envpol.2023.123071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 11/25/2023] [Accepted: 11/28/2023] [Indexed: 01/26/2024]
Abstract
Mercury (Hg) has received increasing public attention owing to its high toxicity and global distribution capability via long-range atmospheric transportation. Guanzhong Basin (GB) is vital for the industrial and economic development of Shaanxi Province. To determine the concentration, spatial distribution, seasonal variation, sources, and health risks of particulate-bound mercury (PBM), PM2.5 samples were collected at three sampling sites representing urban, rural, and remote areas during winter and summer in GB. The three sampling sites were in Xi'an (XN), Taibai (TB), and the Qinling Mountains (QL). The mean PBM concentrations in XN, TB, and QL in winter were 130 ± 115 pg m-3, 57.5 ± 47.3 pg m-3, and 53.6 ± 38.5 pg m-3, respectively, higher than in summer (13.7 ± 7.11 pg m-3, 8.01 ± 2.86 pg m-3, and 7.75 ± 2.85 pg m-3, respectively). PBM concentrations are affected by precipitation, meteorological conditions (temperature and mixed boundary layer), emission sources, and atmospheric transport. During the sampling period, the PBM dry deposition in XN, TB, and QL was 1.90 μg m-2 (2 months), 0.835 μg m-2 (2 months), and 0.787 μg m-2 (2 months), respectively, lower than the range reported in national megacities. According to backward trajectory and potential source contribution factor (PSCF) analysis, mercury pollution in XN is mainly affected by local pollution source emissions, whereas the polluted air mass in TB and QL originates from local anthropogenic emissions and long-distance atmospheric transmission. The non-carcinogenic health risk values of PBM in XN, TB, and QL in winter and summer were less than 1, indicating that the risk of atmospheric PBM to the health of the residents was negligible.
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Affiliation(s)
- Xiaofei Li
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China; Key Laboratory of Aerosol Chemistry and Physics, State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China; National Observation and Research Station of Regional Ecological Environment Change and Comprehensive Management in the Guanzhong Plain, Shaanxi, Xi'an, 710061, China; State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Rui Zhang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Feng Yu
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Jingning Guo
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Wen Yang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junji Cao
- Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
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Wang YT, Lin NH, Chang CT, Huang JC, Lin TC. Fog and rain water chemistry in a tea plantation of northern Taiwan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:96474-96485. [PMID: 37567991 DOI: 10.1007/s11356-023-29263-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 08/06/2023] [Indexed: 08/13/2023]
Abstract
Tea plantations are expanding globally and many are in mountainous areas with frequent fog but few studies have examined fog chemistry in these areas. We examined chemical composition of fog and rain water at a tea plantation in northern Taiwan. Fog water was collected using a Kroneis passive cylindrical fog-water collector and rain water was collected using a 20-cm-diameter funnel. The most abundant ions were Cl- and Na+ in both fog and rain waters due to the proximity of the site to the coast. The order of abundance of other ions was NO3- > Mg2+ > SO42- > Ca2+ > NH4+ > K+ > H+ in fog water and SO42- > K+ > NO3- > NH4+ > Ca2+ > Mg2+ > H+ in rain water. The concentration enrichment ratio (fog to rain) ranged between 2.2 (K+) and 22 (Mg2+) lying between sites near major emission sources and sites in remote areas, possibly because the immediate surrounding landscape is covered with secondary forests although it is near large cities. Factor analysis highlights the influences of sea-salt aerosols on the variation of fog and rain water chemistry. Sea-salt corrections using Na+ as the sea salt tracer led to negative concentrations of Cl- and Mg2+ suggesting that assumptions involved in sea-salt corrections were not satisfied. Agriculture influence is identified as a unique factor for explaining variance of K+, NH4+, and dissolved organic nitrogen (DON) concentrations in fog water but not rain water. Ion concentrations in fog and rain water were generally higher in the weekly samples associated with air trajectories passing through the continental East Asia than those associated with oceanic trajectories pointing to the role of regional pollution sources in affecting local fog and rain water chemistry. Our study highlights greater effects of tea agriculture on fog than rain water chemistry.
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Affiliation(s)
- Yi-Tzu Wang
- Department of Life Science, National Taiwan Normal University, Taipei, 11677, Taiwan
| | - Neng-Huei Lin
- Department of Atmospheric Sciences, National Central University, Taoyuan, 32001, Taiwan
- Center for Environmental Monitoring Technology, National Central University, Taoyuan, 32001, Taiwan
| | - Chung-Te Chang
- Taiwan International Graduate Program (TIGP)-Ph.D. Program on Biodiversity, Tunghai University, Taichung, 407224, Taiwan
- Department of Life Science, Tunghai University, Taichung, 407224, Taiwan
| | - Jr-Chuan Huang
- Department of Geography, National Taiwan University, Taipei, 10617, Taiwan
| | - Teng-Chiu Lin
- Department of Life Science, National Taiwan Normal University, Taipei, 11677, Taiwan.
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Hussain N, Ahmad M, Sipra H, Ali S, Syed JH, Hussain K, Hassan SW. First insight into seasonal variability of urban air quality of northern Pakistan: An emerging issue associated with health risks in Karakoram-Hindukush-Himalaya region. CHEMOSPHERE 2023; 316:137878. [PMID: 36646179 DOI: 10.1016/j.chemosphere.2023.137878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/30/2022] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
There is a dire need of air quality monitoring in the high-mountain areas of Karakoram-Hindu Kush-Himalaya (HKH) region, particularly related to the recent activities undergoing the China-Pakistan Economic Corridor (CPEC). This study presents the first baseline monitoring and evaluation findings from Gilgit city, Gilgit-Baltistan. Hourly data collection for air quality parameters (PM2.5, NO, NO2, SO2, O3 and CO) were measured using air-pointer (recordum, Austria) from 1 Jan 2018 to 31 Mar 2018 (winter) and 1 Jun 2018 to 31 Aug 2018 (summer). Our findings depict PM2.5 health limits were crossed in the winter season, while NO, NO2 and SO2 remained below their health limits. O3 and CO showed a rising trend in summer months, crossing the 8-h health limits during the season. Seasonal correlation in meteorology found an inverse relationship between most parameters and temperatures; reverse was true for O3 and CO. In parallel, thermal optical carbon analysis filter-based sampling characterized air quality into mass concentrations of PM2.5, organic carbon (OC), elemental carbon (EC) and various heavy metals. Filter-based PM2.5 correlated well with analyzer-based PM2.5 for all months that were studied, except February and March 2018. PM2.5, OC and EC were higher in summer as compared to winter, whereas higher heavy metal contributions were measured predominantly during summer. Health impacts were found to be above health limits for Ni in children only. Furthermore, principal component analysis-multiple linear regression (PCA-MLR) technique was applied to determine source apportionment, confirming the role of biomass burning in winters, and vehicular emissions in summers, highlighting the need for flexible monitoring of technologies/approaches, and communications among the various public, private agencies, and all relevant stakeholders.
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Affiliation(s)
- Nasir Hussain
- Department of Environmental Sciences, Karakorum International University, Gilgit, Pakistan; Gilgit-Baltistan Environmental Protection Agency (GB-EPA), Gilgit, Pakistan
| | - Masroor Ahmad
- Department of Environmental Sciences, Karakorum International University, Gilgit, Pakistan
| | - Hassaan Sipra
- Centre for Climate Research and Development, COMSATS University Islamabad, Park Road Tarlai Kalan, 45550, Islamabad, Pakistan
| | - Shuakat Ali
- Department of Environmental Sciences, Karakorum International University, Gilgit, Pakistan
| | - Jabir Hussain Syed
- Department of Meteorology, COMSATS University Islamabad, Park Road Tarlai Kalan, 45550, Islamabad, Pakistan; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, 11 Yuk Choi Rd, Hung Hom, Hong Kong.
| | - Khadim Hussain
- Gilgit-Baltistan Environmental Protection Agency (GB-EPA), Gilgit, Pakistan
| | - Syed Waqar Hassan
- Gilgit-Baltistan Environmental Protection Agency (GB-EPA), Gilgit, Pakistan
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Xu Y, Li Q, Xie S, Zhang C, Yan F, Liu Y, Kang S, Gao S, Li C. Composition and sources of heavy metals in aerosol at a remote site of Southeast Tibetan Plateau, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 845:157308. [PMID: 35839894 DOI: 10.1016/j.scitotenv.2022.157308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 07/04/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Knowledge of the elemental composition of aerosols at remote sites is important for evaluating the influence of anthropogenic activities. In this study, the elemental composition and sources of total suspended particles (TSP) at Yaze, a remote site in the southeastern Tibetan Plateau (TP), were investigated. The results showed that the mean elemental concentrations at Yaze were relatively low compared with those in other areas of the TP. Seasonal variations in the studied elements was characterized by low and high concentrations during the monsoon and non-monsoon periods, respectively. The enrichment factors (EFs) for some heavy metals at Yaze were slightly higher than those at Nam Co station (inland TP) but much lower than those at Mt. Yulong (southeastern TP) and in the Indian megacity of Delhi, indicating fewer anthropogenic influences at the study site relative to sites close to severely polluted regions. For the studied elements, three major sources were identified: crustal origins (e.g., Al and Fe), anthropogenic origins (e.g., Zn and Cd) and mixed origins (e.g., As and Bi). Further analysis by potential source contribution functions showed that the local TP was the primary source for elements of crustal origins. Correspondingly, the typical heavy metals were mainly attributed to pollution emitted from anthropogenic activities and transported over long-range from both South and Southeast Asia. This work demonstrates the transport of heavy metals from external sources to remote sites in the southeastern TP. These results are also useful for interpreting the historical profiles of heavy metals in the ice cores of the TP.
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Affiliation(s)
- Yinbo Xu
- School of Geographical Sciences, Southwest University, Chongqing 400045, China; State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Qing Li
- School of Geographical Sciences, Southwest University, Chongqing 400045, China
| | - Shiyou Xie
- School of Geographical Sciences, Southwest University, Chongqing 400045, China
| | - Chao Zhang
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fangping Yan
- State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yixi Liu
- State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shaopeng Gao
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Chaoliu Li
- State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Chen P, Kang S, Zhang L, Abdullaev SF, Wan X, Zheng H, Maslov VA, Abdyzhapar Uulu S, Safarov MS, Tripathee L, Li C. Organic aerosol compositions and source estimation by molecular tracers in Dushanbe, Tajikistan. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 302:119055. [PMID: 35227849 DOI: 10.1016/j.envpol.2022.119055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/20/2022] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
To elucidate the molecular composition and sources of organic aerosols in Central Asia, carbonaceous compounds, major ions, and 15 organic molecular tracers of total suspended particulates (TSP) were analyzed from September 2018 to August 2019 in Dushanbe, Tajikistan. Extremely high TSP concentrations (annual mean ± std: 211 ± 131 μg m-3) were observed, particularly during summer (seasonal mean ± std: 333 ± 183 μg m-3). Organic carbon (OC: 11.9 ± 7.0 μg m-3) and elemental carbon (EC: 5.1 ± 2.2 μg m-3) exhibited distinct seasonal variations from TSP, with the highest values occurring in winter. A high concentration of Ca2+ was observed (11.9 ± 9.2 μg m-3), accounting for 50.8% of the total ions and reflecting the considerable influence of dust on aerosols. Among the measured organic molecular tracers, levoglucosan was the predominant compound (632 ± 770 ng m-3), and its concentration correlated significantly with OC and EC during the study period. These findings highlight biomass burning (BB) as an important contributor to the particulate air pollution in Dushanbe. High ratios of levoglucosan to mannosan, and syringic acid to vanillic acid suggest that mixed hardwood and herbaceous plants were the main burning materials in the area, with softwood being a minor one. According to the diagnostic tracer ratio, OC derived from BB constituted a large fraction of the primary OC (POC) in ambient aerosols, accounting for an annual mean of nearly 30% and reaching 63% in winter. The annual contribution of fungal spores to POC was 10%, with a maximum of 16% in spring. Measurements of plant debris, accounting for 3% of POC, divulged that these have the same variation as fungal spores.
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Affiliation(s)
- Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Lanxin Zhang
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Sabur F Abdullaev
- S.U.Umarov Physical Technical Institute of the National Academy of Sciences of Tajikistan, Dushanbe, 734063, Tajikistan
| | - Xin Wan
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100085, China
| | - Huijun Zheng
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Vladimir A Maslov
- S.U.Umarov Physical Technical Institute of the National Academy of Sciences of Tajikistan, Dushanbe, 734063, Tajikistan
| | - Salamat Abdyzhapar Uulu
- Research Center for Ecology and Environment of Central Asia (Bishkek), 720001, Kyrgyzstan; Geography Department, Geology Institute, National Academy of Sciences, 720001, Kyrgyzstan
| | - Mustafo S Safarov
- Research Center for Ecology and Environment of Central Asia (Dushanbe), 734063, Tajikistan
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Chaoliu Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China
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Bhattarai H, Tripathee L, Kang S, Chen P, Sharma CM, Ram K, Guo J, Rupakheti M. Nitrogenous and carbonaceous aerosols in PM 2.5 and TSP during pre-monsoon: Characteristics and sources in the highly polluted mountain valley. J Environ Sci (China) 2022; 115:10-24. [PMID: 34969440 DOI: 10.1016/j.jes.2021.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 06/09/2021] [Accepted: 06/20/2021] [Indexed: 06/14/2023]
Abstract
This study reports for the first time a comprehensive analysis of nitrogenous and carbonaceous aerosols in simultaneously collected PM2.5 and TSP during pre-monsoon (March-May 2018) from a highly polluted urban Kathmandu Valley (KV) of the Himalayan foothills. The mean mass concentration of PM2.5 (129.8 µg/m3) was only ~25% of TSP mass (558.7 µg/ m3) indicating the dominance of coarser mode aerosols. However, the mean concentration as well as fractional contributions of water-soluble total nitrogen (WSTN) and carbonaceous species reveal their predominance in find-mode aerosols. The mean mass concentration of WSTN was 17.43±4.70 µg/m3 (14%) in PM2.5 and 24.64±8.07 µg/m3 (5%) in TSP. Moreover, the fractional contribution of total carbonaceous aerosols (TCA) is much higher in PM2.5 (~34%) than that in TSP (~20%). The relatively low OC/EC ratio in PM2.5 (3.03 ± 1.47) and TSP (4.64 ± 1.73) suggests fossil fuel combustion as the major sources of carbonaceous aerosols with contributions from secondary organic aerosols. Five-day air mass back trajectories simulated with the HYSPLIT model, together with MODIS fire counts indicate the influence of local emissions as well as transported pollutants from the Indo-Gangetic Plain region to the south of the Himalayan foothills. Principal component analysis (PCA) also suggests a mixed contribution from other local anthropogenic, biomass burning, and crustal sources. Our results highlight that it is necessary to control local emissions as well as regional transport while designing mitigation measures to reduce the KV's air pollution.
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Affiliation(s)
- Hemraj Bhattarai
- Earth System Science Programme and Graduate Division of Earth and Atmospheric Sciences, The Chinese University of Hong Kong, Hong Kong, China; Himalayan Environment Research Institute (HERI), Kathmandu 44602, Nepal
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu 44602, Nepal.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Chhatra Mani Sharma
- Himalayan Environment Research Institute (HERI), Kathmandu 44602, Nepal; Central Department of Environmental Sciences, Tribhuvan University, Kathmandu 44613, Nepal
| | - Kirpa Ram
- Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221005, India
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
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Maharjan L, Kang S, Tripathee L, Gul C, Zheng H, Li Q, Chen P, Rai M, Santos E. Atmospheric particle-bound polycyclic aromatic compounds over two distinct sites in Pakistan: Characteristics, sources and health risk assessment. J Environ Sci (China) 2022; 112:1-15. [PMID: 34955192 DOI: 10.1016/j.jes.2021.04.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 06/14/2023]
Abstract
Much attention is drawn to polycyclic aromatic hydrocarbons (PAHs) as an air pollutant due to their toxic, mutagenic and carcinogenic properties. Therefore, to understand the levels, seasonality, sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan, total suspended particle (TSP) samples were collected for over one year period. The average total PAH concentrations were 31.5 ± 24.4 and 199 ± 229 ng/m3 in Karachi and Mardan, respectively. The significantly lower concentration in Karachi was attributed to diffusion and dilution of the PAHs by the influence of clean air mass from the Arabian sea and high temperature, enhancing the volatilization of the particle phase PAHs to the gas phase. Conversely, the higher concentration (~6 times) in Mardan was due to large influence from local and regional emission sources. A clear seasonality was observed at both the sites, with the higher values in winter and post-monsoon due to higher emissions and less scavenging, and lower values during monsoon season due to the dilution effect. Diagnostic ratios and principal component analysis indicated that PAHs in both sites originated from traffic and mixed combustion sources (fossil fuels and biomass). The average total BaP equivalent concentrations (BaPeq) in Karachi and Mardan were 3.26 and 34 ng/m3, respectively, which were much higher than the WHO guideline of 1 ng/m3. The average estimates of incremental lifetime cancer risk from exposure to airborne BaPeq via inhalation indicated a risk to human health from atmospheric PAHs at both sites.
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Affiliation(s)
- Linda Maharjan
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China; Chinese Academy of Sciences (CAS) Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Himalayan Environment Research Institute, Kathmandu 44600, Nepal.
| | - Chaman Gul
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Reading Academy, Nanjing University of Information Science & Technology, Nanjing, Jiangsu 210044, China
| | - Huijun Zheng
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Quanlian Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Mukesh Rai
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ewerton Santos
- Departamento de Química, Universidade Federal de Sergipe, São Cristóvão, Sergipe SE 49100-000, Brazil
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Guo J, Sharma CM, Tripathee L, Kang S, Fu X, Huang J, Shrestha KL, Chen P. Source identification of atmospheric particle-bound mercury in the Himalayan foothills through non-isotopic and isotope analyses. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117317. [PMID: 33990047 DOI: 10.1016/j.envpol.2021.117317] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
This study reports on the sources of atmospheric particle-bound mercury (HgP) in less studied regions of Nepal based on the analysis of stable mercury (Hg) isotopes in aerosol samples from two neighboring areas with high and low anthropogenic emissions (Kathmandu and Dhulikhel, respectively) during 2018. Although the Indian monsoon and westerlies are generally regarded as the primary carriers of pollutants to this region via the heavily industrialized Indo-Gangetic Plain, the concentrations of total suspended particles (TSP) and HgP in Kathmandu were higher than those in Dhulikhel, thus suggesting a substantial contribution from local sources. Both isotopic (δ200Hg and Δ199Hg) and non-isotopic evidence indicated that dust, waste burning, and industrial byproducts (without Hg amalgamation) were the major sources of Hg in Kathmandu during the study period. Mercury may have been transported via air masses from Kathmandu to Dhulikhel, as indicated by the similar organic carbon/elemental carbon ratios and seasonal trends of TSP and HgP in these two locations. Local anthropogenic sources were found to contribute significantly to atmospheric Hg pollution through dust resuspension. Therefore, dust resuspension should be considered when evaluating the long-range transport of air pollutants such as Hg, particularly in anthropogenically stressed areas.
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Affiliation(s)
- Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Chhatra Mani Sharma
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China; Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuewu Fu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 99 Lincheng West Road, Guiyang, 550081, China
| | - Jie Huang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese, Academy of Sciences, Beijing, 100101, China
| | - Kundan Lal Shrestha
- Department of Environmental Science and Engineering, Kathmandu University, Dhulikhel, Nepal
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
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Chemical Composition and Source Apportionment of Total Suspended Particulate in the Central Himalayan Region. ATMOSPHERE 2021. [DOI: 10.3390/atmos12091228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The present study analyzes data from total suspended particulate (TSP) samples collected during 3 years (2005–2008) at Nainital, central Himalayas, India and analyzed for carbonaceous aerosols (organic carbon (OC) and elemental carbon (EC)) and inorganic species, focusing on the assessment of primary and secondary organic carbon contributions (POC, SOC, respectively) and on source apportionment by positive matrix factorization (PMF). An average TSP concentration of 69.6 ± 51.8 µg m−3 was found, exhibiting a pre-monsoon (March–May) maximum (92.9 ± 48.5 µg m−3) due to dust transport and forest fires and a monsoon (June–August) minimum due to atmospheric washout, while carbonaceous aerosols and inorganic species expressed a similar seasonality. The mean OC/EC ratio (8.0 ± 3.3) and the good correlations between OC, EC, and nss-K+ suggested that biomass burning (BB) was one of the major contributing factors to aerosols in Nainital. Using the EC tracer method, along with several approaches for the determination of the (OC/EC)pri ratio, the estimated SOC component accounted for ~25% (19.3–29.7%). Furthermore, TSP source apportionment via PMF allowed for a better understanding of the aerosol sources in the Central Himalayan region. The key aerosol sources over Nainital were BB (27%), secondary sulfate (20%), secondary nitrate (9%), mineral dust (34%), and long-range transported mixed marine aerosol (10%). The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) analyses were also used to identify the probable regional source areas of resolved aerosol sources. The main source regions for aerosols in Nainital were the plains in northwest India and Pakistan, polluted cities like Delhi, the Thar Desert, and the Arabian Sea area. The outcomes of the present study are expected to elucidate the atmospheric chemistry, emission source origins, and transport pathways of aerosols over the central Himalayan region.
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Izhar S, Gupta T, Qadri AM, Panday AK. Wintertime chemical characteristics of aerosol and their role in light extinction during clear and polluted days in rural Indo Gangetic plain. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 282:117034. [PMID: 33839614 DOI: 10.1016/j.envpol.2021.117034] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/23/2021] [Accepted: 03/27/2021] [Indexed: 06/12/2023]
Abstract
This paper reports the chemical and light extinction characteristics of fine aerosol (PM2.5) during the winter period (2017-18) at Lumbini, Nepal, a rural site on the Indo Gangetic Plains. A modified IMPROVE algorithm was employed to reconstruct light extinction by chemical constituents of aerosol. The fine aerosol levels impacted visibility adversely during daytime, but during nighttime visibility was controlled by fog droplets rather than by aerosols. The PM2.5 chemical constituents showed varying characteristics during clear and polluted days. The average NO3-/SO42- concentration ratio was 0.57 during clear and 1.36 and polluted days, signifying a change in secondary inorganics and formation processes mainly due to decreasing photochemical production and due to increased partitioning of nitrate particles at a lower temperature. The increased secondary organics contribution and the higher OM/OC ratio (2.2) during polluted days showed the vital role of aqueous processing and biomass burning emissions in determining the concentration of organics. Total light extinction was 2.3 times higher on polluted days compared to clear days, while the PM2.5 mass concentration was 1.5 times higher. This variation in mass and extinction order signifies that various chemical components in fine particles have a more considerable impact on light extinction. On clear days we found that carbonaceous particles (OM and EC) made a major contribution to light extinction. In contrast, the extinction contribution by secondary inorganic (especially NH4NO3) increased significantly during polluted days, with hygroscopic growth and enhanced scattering efficiency at higher RH conditions playing a major role. The comparison between clear and polluted days altogether suggests that regulating the nitrate sources can help significantly in improving the visibility levels and restrict fog haze development during wintertime in rural IGP.
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Affiliation(s)
- Saifi Izhar
- Department of Civil Engineering, Indian Institute of Technology Kanpur, India; International Centre for Integrated Mountain Development (ICIMOD), Khumaltar, Lalitpur, Nepal.
| | - Tarun Gupta
- Department of Civil Engineering, Indian Institute of Technology Kanpur, India; Centre of Environmental Science and Engineering, Indian Institute of Technology Kanpur, India
| | - Adnan Mateen Qadri
- Department of Civil Engineering, Indian Institute of Technology Kanpur, India
| | - Arnico K Panday
- Ullens Education Foundation, Lalitpur, Nepal; International Centre for Integrated Mountain Development (ICIMOD), Khumaltar, Lalitpur, Nepal
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Bhattarai H, Tripathee L, Kang S, Sharma CM, Chen P, Guo J, Ghimire PS. Concentration, sources and wet deposition of dissolved nitrogen and organic carbon in the Northern Indo-Gangetic Plain during monsoon. J Environ Sci (China) 2021; 102:37-52. [PMID: 33637262 DOI: 10.1016/j.jes.2020.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/21/2020] [Accepted: 09/04/2020] [Indexed: 06/12/2023]
Abstract
Precipitation represents an important phenomenon for carbon and nitrogen deposition. Here, the concentrations and fluxes of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) with their potential sources were analyzed in wet precipitation during summer monsoon from the Northern Indo-Gangetic Plain (IGP), important but neglected area. The volume-weighted mean (VWM) concentration of DOC and TDN were 687.04 and 1210.23 µg/L, respectively. Similarly, the VWM concentration of major ions were in a sequence of NH4+ > Ca2+ > SO42- > Na+ > K+ > NO3- > Cl- > Mg2+ > F- > NO2-, suggesting NH4+ and Ca2+ from agricultural activities and crustal dust played a vital role in precipitation chemistry. Moreover, the wet deposition flux of DOC and TDN were 9.95 and 17.06 kg/(ha⋅year), respectively. The wet deposition flux of inorganic nitrogen species such as NH4+-N and NO3--N were 14.31 and 0.47 kg/(ha⋅year), respectively, demonstrating the strong influence of emission sources and precipitation volume. Source attribution from different analysis suggested the influence of biomass burning on DOC and anthropogenic activities (agriculture, animal husbandry) on nitrogenous species. The air-mass back trajectory analysis indicated the influence of air masses originating from the Bay of Bengal, which possibly carried marine and anthropogenic pollutants along with the biomass burning emissions to the sampling site. This study bridges the data gap in the less studied part of the northern IGP region and provides new information for policy makers to deal with pollution control.
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Affiliation(s)
- Hemraj Bhattarai
- Earth System Science Programme and Graduate Division of Earth and Atmospheric Sciences, The Chinese University of Hong Kong, Hong Kong, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal; Kathmandu Center for Research and Education (KCRE), Kathmandu, Nepal
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100101, China; Chinese Academy of Sciences (CAS) Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | | | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Prakriti Sharma Ghimire
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
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Investigation of Aerosol Climatology and Long-Range Transport of Aerosols over Pokhara, Nepal. ATMOSPHERE 2020. [DOI: 10.3390/atmos11080874] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study presents the spectral monthly and seasonal variation of aerosol optical depth (τAOD), single scattering albedo (SSA), and aerosol absorption optical depth (AAOD) between 2010 and 2018 obtained from the Aerosol Robotic Network (AERONET) over Pokhara, Nepal. The analysis of these column-integrated aerosol optical data suggests significant monthly and seasonal variability of aerosol physical and optical properties. The pre-monsoon season (March to May) has the highest observed τAOD(0.75 ± 0.15), followed by winter (December to February, 0.47 ± 0.12), post-monsoon (October and November, 0.39 ± 0.08), and monsoon seasons (June to September, 0.27 ± 0.13), indicating seasonal aerosol loading over Pokhara. The variability of Ångström parameters, α, and β, were computed from the linear fit line in the logarithmic scale of spectral τAOD, and used to analyze the aerosol physical characteristics such as particle size and aerosol loading. The curvature of spectral τAOD, α’, computed from the second-order polynomial fit, reveals the domination by fine mode aerosol particles in the post-monsoon and winter seasons, with coarse mode dominating in monsoon, and both modes contributing in the pre-monsoon. Analysis of air mass back trajectories and observation of fire spots along with aerosol optical data and aerosol size spectra suggest the presence of mixed types of transboundary aerosols, such as biomass, urban-industrial, and dust aerosols in the atmospheric column over Pokhara.
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Zheng H, Kang S, Chen P, Li Q, Tripathee L, Maharjan L, Guo J, Zhang Q, Santos E. Sources and spatio-temporal distribution of aerosol polycyclic aromatic hydrocarbons throughout the Tibetan Plateau. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114144. [PMID: 32062463 DOI: 10.1016/j.envpol.2020.114144] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/26/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
With the recent rapid development of urbanization, atmospheric pollutants such as polycyclic aromatic hydrocarbons (PAHs) have attracted wide attention, particularly in remote regions. The Tibetan Plateau (TP), known as the third pole is adjacent to areas with heavy atmospheric pollution, such as South and East Asia. However, the spatial distribution and sources of PAHs on the TP remain unclear. Thus, we investigated the sources and spatio-temporal distributions of PAHs on the TP by combining aerosol sample data from six sites, including Ngari (NG), Laohugou (LHG), Beiluhe (BLH), Nam Co (NMC), Everest (EV), and Yulong (YL), in 2014 and 2016. The average concentrations of 15 PAHs at the six sites ranged from 3.4 to 15.2 ng m-3, with a decreasing trend from the marginal to inner areas of the plateau. The highest concentration was that in YL in the southeastern part of the TP, with an average of 15.2 ng m-3. The PAH concentrations in NG, NMC, and YL were higher in autumn and winter and lower in summer. High molecular weight PAHs usually exists in the particulate phase whereas tricyclic PAHs can change from particulate to gaseous phase, therefore it can indicate long-range transport. Tricyclic PAHs were the dominant PAHs on the TP (44%-58%), indicating long-range atmospheric transport as the major source of PAHs. Principal component analysis (PCA) and diagnostic ratio analysis showed that biomass and coal combustion were the major sources of PAHs in inland areas of the TP; however, marginal plateau areas were affected by fossil fuel emissions. Compared with levels in Beijing and other urban sites, the toxic equivalent quantity (TEQ) was low (0.36-1.06 ng m-3), suggesting a low risk to human and ecosystem health.
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Affiliation(s)
- Huijun Zheng
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Quanlian Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Linda Maharjan
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Qianggong Zhang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ewerton Santos
- Departamento de Química, Universidade Federal de Sergipe, São Cristóvão, Sergipe, 49100-000, Brazil
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Chen P, Kang S, Tripathee L, Ram K, Rupakheti M, Panday AK, Zhang Q, Guo J, Wang X, Pu T, Li C. Light absorption properties of elemental carbon (EC) and water-soluble brown carbon (WS-BrC) in the Kathmandu Valley, Nepal: A 5-year study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114239. [PMID: 32114124 DOI: 10.1016/j.envpol.2020.114239] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/22/2019] [Accepted: 02/18/2020] [Indexed: 05/21/2023]
Abstract
This study presents a comprehensive analysis of organic carbon (OC), elemental carbon (EC), and particularly the light absorption characteristics of EC and water-soluble brown carbon (WS-BrC) in total suspended particles in the Kathmandu Valley from April 2013 to January 2018. The mean OC, EC, and water-soluble organic carbon (WSOC) concentrations were 34.8 ± 27.1, 9.9 ± 5.8, and 17.4 ± 12.5 μg m-3, respectively. A clear seasonal variation was observed for all carbonaceous components with higher concentrations occurring during colder months and lower concentrations in the monsoon season. The relatively low OC/EC ratio (3.6 ± 2.0) indicates fossil fuel combustion as the primary source of carbonaceous components. The optical attenuation (ATN) at 632 nm was significantly connected with EC loading (ECS) below 15 μg cm-2 but ceased as ECS increased, reflecting the increased influence of the shadowing effect. The derived average mass absorption cross-section of EC (MACEC) (7.0 ± 4.2 m2 g-1) is comparable to that of freshly emitted EC particles, further attesting that EC was mainly produced from local sources with minimal atmospheric aging processes. Relatively intensive coating with organic aerosols and/or salts (e.g., sulfate, nitrate) was probably the reason for the slightly higher MACEC during the monsoon season, whereas increased biomass burning was a major factor leading to lower MACEC in other seasons. The average MACWS-BrC at 365 nm was 1.4 ± 0.3 m2 g-1 with minimal seasonal variations. In contrast to MACEC, biomass burning was the main reason for a higher MACWS-BrC in the non-monsoon season. The relative light absorption contribution of WS-BrC to EC was 9.9% over the 300-700 nm wavelength range, with a slightly higher ratio (13.6%) in the pre-monsoon season. Therefore, both EC and WS-BrC should be considered in the study of optical properties and radiative forcing of carbonaceous aerosols in this region.
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Affiliation(s)
- Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China.
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Kirpa Ram
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China; Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, 221005, India
| | | | - Arnico K Panday
- International Centre for Integrated Mountain Development, 44700, Kathmandu, Nepal
| | - Qianggong Zhang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Xiaoxiang Wang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Tao Pu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Chaoliu Li
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China
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Microbial Community Composition Analysis in Spring Aerosols at Urban and Remote Sites over the Tibetan Plateau. ATMOSPHERE 2020. [DOI: 10.3390/atmos11050527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This study presents features of airborne culturable bacteria and fungi from three different sites (Lanzhou; LZ; 1520 m ASL, Lhasa; LS; 3640 m ASL and Qomolangma; ZF; 4276 m ASL) representing urban (LZ and LS) and remote sites (ZF) over the Tibetan Plateau (TP). Total suspended particle (TSP) samples were collected with an air sampler (Laoying 2030, China) on a quartz filter. Community structures of bacteria and fungi were studied and compared among three different locations. The average levels of bacterial load in the outdoor air ranged from approximately 8.03 × 101 to 3.25 × 102 CFU m–3 (Colony forming unit per m3). However, the average levels of fungal loads ranged from approximately 3.88 × 100 to 1.55 × 101 CFU m−3. Bacterial load was one magnitude higher at urban sites LZ (2.06 × 102–3.25 × 102 CFU m−3) and LS (1.96 × 102–3.23 × 102 CFU m−3) compared to remote sites ZF (8.03 × 101–9.54 × 101 CFU m−3). Similarly, the maximum fungal load was observed in LZ (1.02 × 101–1.55 × 101 CFU m−3) followed by LS (1.03 × 101–1.49 × 101 CFU m−3) and ZF (3.88 × 100–6.26 × 100 CFU m−3). However, the maximum microbial concentration was observed on the same day of the month, corresponding to a high dust storm in Lanzhou during the sampling period. The reported isolates were identified by phylogenetic analysis of 16S rRNA genes for bacteria and ITS sequences for fungi amplified from directly extracted DNA. Bacterial isolates were mostly associated with Proteobacteria, Eurotiomycetes and Bacillus, whereas fungal isolates were mostly Aspergillus and Alternaria. Overall, this is a pioneer study that provides information about the airborne microbial concentration and composition of three sites over the TP region depending on environmental parameters. This study provided preliminary insight to carry out more advanced and targeted analyses of bioaerosol in the sites presented in the study.
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Chen P, Kang S, Gul C, Tripathee L, Wang X, Hu Z, Li C, Pu T. Seasonality of carbonaceous aerosol composition and light absorption properties in Karachi, Pakistan. J Environ Sci (China) 2020; 90:286-296. [PMID: 32081324 DOI: 10.1016/j.jes.2019.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/21/2019] [Accepted: 12/12/2019] [Indexed: 05/21/2023]
Abstract
Characteristics of carbonaceous aerosol (CA) and its light absorption properties are limited in Karachi, which is one of the most polluted metropolitan cities in South Asia. This study presents a comprehensive measurement of seasonality of CA compositions and mass absorption cross-section (MAC) of elemental carbon (EC) and water-soluble organic carbon (WSOC) in total suspended particles (TSP) collected from February 2015 to March 2017 in the southwest part of Karachi. The average TSP, organic carbon (OC), and EC concentrations were extremely high with values as 391.0 ± 217.0, 37.2 ± 28.0, and 8.53 ± 6.97 μg/m3, respectively. These components showed clear seasonal variations with high concentrations occurring during fall and winter followed by spring and summer. SO42-, NO3-, K+, and NH4+ showed similar variations with CA, implying the significant influence on atmospheric pollutants from anthropogenic activities. Relatively lower OC/EC ratio (4.20 ± 2.50) compared with remote regions further indicates fossil fuel combustion as a primary source of CA. Meanwhile, sea salt and soil dust are important contribution sources for TSP. The average MAC of EC (632 nm) and WSOC (365 nm) were 6.56 ± 2.70 and 0.97 ± 0.37 m2/g, respectively. MACEC is comparable to that in urban areas but lower than that in remote regions, indicating the significant influence of local emissions. MACWSOC showed opposite distribution with EC, further suggesting that OC was significantly affected by local fossil fuel combustion. In addition, dust might be an important factor increasing MACWSOC particularly during spring and summer.
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Affiliation(s)
- Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100101, China.
| | - Chaman Gul
- Reading Academy, Nanjing University of Information Science and Technology, Nanjing, Jiangsu, 210044, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Xiaoxiang Wang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Zhaofu Hu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Chaoliu Li
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing 100101, China
| | - Tao Pu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
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Chen P, Kang S, Tripathee L, Panday AK, Rupakheti M, Rupakheti D, Zhang Q, Guo J, Li C, Pu T. Severe air pollution and characteristics of light-absorbing particles in a typical rural area of the Indo-Gangetic Plain. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:10617-10628. [PMID: 31940147 DOI: 10.1007/s11356-020-07618-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Total suspended particles (TSP) were collected in Lumbini from April 2013 to March 2016 to better understand the characteristics of carbonaceous aerosol (CA) concentrations, compositions and sources and their light absorption properties in rural region of severe polluted Indo-Gangetic Plain (IGP). Extremely high TSP (203.9 ± 109.6 μg m-3), organic carbon (OC 32.1 ± 21.7 μg m-3), elemental carbon (EC 6.44 ± 3.17 μg m-3) concentrations were observed in Lumbini particularly during winter and post-monsoon seasons, reflecting the combined influences of emission sources and weather conditions. SO42- (7.34 ± 4.39 μg m-3) and Ca2+ (5.46 ± 5.20 μg m-3) were the most dominant anion and cation in TSP. These components were comparable to those observed in urban areas in South and East Asia but significantly higher than those in remote regions over the Himalayas and Tibetan Plateau, suggesting severe air pollution in the study region. Various combustion activities including industry, vehicle emission, and biomass burning are the main reasons for high pollutant concentrations. The variation of OC/EC ratio further suggested that biomass such as agro-residue burning contributed a lot for CA, particularly during the non-monsoon season. The average mass absorption cross-section of EC (MACEC) and water-soluble organic carbon (MACWSOC) were 7.58 ± 3.39 and 1.52 ± 0.41 m2 g-1, respectively, indicating that CA in Lumbini was mainly affected by local emissions. Increased biomass burning decreased MACEC; whereas, it could result in high MACWSOC during the non-monsoon season. Furthermore, dust is one important factor causing higher MACWSOC during the pre-monsoon season.
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Affiliation(s)
- Pengfei Chen
- State Key Laboratory of Cryospheric Science, Chinese Academy of Sciences (CAS), Northwest Institute of Eco-Environment and Resources, CAS, DongGangXi Road, Chengguan District, Lanzhou, 730000, People's Republic of China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Chinese Academy of Sciences (CAS), Northwest Institute of Eco-Environment and Resources, CAS, DongGangXi Road, Chengguan District, Lanzhou, 730000, People's Republic of China.
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China.
- University of CAS, Beijing, 100049, China.
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Chinese Academy of Sciences (CAS), Northwest Institute of Eco-Environment and Resources, CAS, DongGangXi Road, Chengguan District, Lanzhou, 730000, People's Republic of China
| | - Arnico K Panday
- International Centre for Integrated Mountain Development, Kathmandu, 44700, Nepal
| | | | - Dipesh Rupakheti
- State Key Laboratory of Cryospheric Science, Chinese Academy of Sciences (CAS), Northwest Institute of Eco-Environment and Resources, CAS, DongGangXi Road, Chengguan District, Lanzhou, 730000, People's Republic of China
| | - Qianggong Zhang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Chinese Academy of Sciences (CAS), Northwest Institute of Eco-Environment and Resources, CAS, DongGangXi Road, Chengguan District, Lanzhou, 730000, People's Republic of China
| | - Chaoliu Li
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China
| | - Tao Pu
- State Key Laboratory of Cryospheric Science, Chinese Academy of Sciences (CAS), Northwest Institute of Eco-Environment and Resources, CAS, DongGangXi Road, Chengguan District, Lanzhou, 730000, People's Republic of China
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Sundriyal S, Shukla T, Tripathee L, Dobhal DP. Natural versus anthropogenic influence on trace elemental concentration in precipitation at Dokriani Glacier, central Himalaya, India. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:3462-3472. [PMID: 31845255 DOI: 10.1007/s11356-019-07102-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
Atmospheric pollutant transport and deposition at the Himalaya affects the climate, cryosphere, and monsoon patterns and impose an adverse impact over the Himalayan ecosystem. At present, the data on trace elements (TEs) concentrations and dynamics over the high-altitude Himalayan region are scarce and has received less attention. Therefore, in the present study, we investigated the TEs concentration and depositional pattern at Dokriani Glacier, central Himalaya to understand their levels, dynamics, and potential effects. A total of 39 samples were collected from two snowpit stratigraphies, deposited during non-monsoon period and monsoonal precipitation between 4530 to 4630 m a.s.l. altitude in the year 2017. The results of analyzed trace metals (Al, Cr, Mn, Fe, Sr, Co, Ni, Cu, Zn, Cd, As, and Pb) showed high enrichment values for Zn, Cr, Co, Ni and Mn compared to other parts of the Himalayan region, suggesting the influence of anthropogenic emissions (e.g., fossil fuel, metal production, and industrial processes) from urbanized areas of South Asia. Our results also revealed the possible health effects related to the enrichment of Zn and Cd, which may be responsible for skin-related diseases in Uttarakhand region. We attribute increasing anthropogenic activities in the environment to have a significant impact on the ecosystem health of the central Himalayan region. This study provides the baseline information on TEs concentration and sources in the Himalayas, which needs wide dissemination to scientific community as well as policymakers. Therefore, systematic observations, management, and preparing action plan to overcome the health effects from TEs pollution are urgently needed over the remote, pristine Himalayan region.
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Affiliation(s)
- Shipika Sundriyal
- Environmental and Hydrology Division, National Institute of Hydrology, Roorkee, 247667, India.
| | - Tanuj Shukla
- Indian Institute of Technology, Kalyanpur, Kanpur, 208016, India
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, Gansu, China
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Gaonkar CV, Kumar A, Matta VM, Kurian S. Assessment of crustal element and trace metal concentrations in atmospheric particulate matter over a coastal city in the Eastern Arabian Sea. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2020; 70:78-92. [PMID: 31613714 DOI: 10.1080/10962247.2019.1680458] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 06/10/2023]
Abstract
Major/crustal elements (Al, Ca, Mg, K, and Fe) and trace metals (Mn, Cr, Cu, Pb, Zn, and Ni) in atmospheric particulate matter at three sites in Goa (a coastal city in the Eastern Arabian Sea) were assessed during winter (December) and summer (March-May) months of 2015. A significant spatial and temporal variability was observed in PM10 mass concentration, crustal element, and trace metal composition at the sampling area (pristine, urban, and industrial locations). Using a diagnostic crustal element ratio (Fe/Al, Ca/Al, and Mg/Al), mineral dust components were characterized and found to show large spatial and temporal variability. The concentration levels of trace metals were further assessed for enrichment factor (EF) analysis, wherein reported elements were classified into two major groups. The first group consists of Cr, Cu, and Pb with 10< EF < 100 compared to continental crustal values (w.r.t. Al), suggesting a dominant contribution from anthropogenic sources with minor contribution from natural sources; the second group consists of Zn and Ni showing very high EF (>100)-these are solely derived from anthropogenic sources. Source identification for trace metals was further assessed based on principle component analysis (PCA). PCA highlights that the major contribution of trace metals is from anthropogenic emissions at all three locations. However, contributions from mineral dust were observed at pristine and urban locations during winter months. The reported data of trace metal concentrations in aerosols give baseline information on the atmospheric supply of micronutrients to the Arabian Sea, which has implications for the various surface ocean biogeochemical processes.Implications: This paper reports on crustal and trace metal composition and concentration level in atmospheric aerosols over a coastal city located on the Eastern Arabian Sea. This study highlights the role of various factors (meteorology and emission sources) controlling the abundance of metals over a coastal site. The contribution from various sources (anthropogenic vis-à-vis natural) has also been identified using enrichment factor analysis as well as principle component analysis. This study has implications for the supply of micronutrients to the coastal Arabian Sea, which can significantly impact various surface ocean biogeochemical processes.
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Affiliation(s)
- Cynthia V Gaonkar
- The School of Earth, Ocean and Atmospheric Sciences, Goa University, Taleigao, India
| | - Ashwini Kumar
- CSIR-National Institute of Oceanography, Doan Paula, India
| | - Vishnu Murty Matta
- The School of Earth, Ocean and Atmospheric Sciences, Goa University, Taleigao, India
| | - Siby Kurian
- CSIR-National Institute of Oceanography, Doan Paula, India
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Chen P, Kang S, Li C, Zhang Q, Guo J, Tripathee L, Zhang Y, Li G, Gul C, Cong Z, Wan X, Niu H, Panday AK, Rupakheti M, Ji Z. Carbonaceous aerosol characteristics on the Third Pole: A primary study based on the Atmospheric Pollution and Cryospheric Change (APCC) network. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:49-60. [PMID: 31302402 DOI: 10.1016/j.envpol.2019.06.112] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/20/2019] [Accepted: 06/27/2019] [Indexed: 06/10/2023]
Abstract
Carbonaceous aerosols (CAs) scatter and absorb incident solar radiation in the atmosphere, thereby influencing the regional climate and hydrological cycle, particularly in the Third Pole (TP). Here, we present the characteristics of CAs at 19 observation stations from the Atmospheric Pollution and Cryospheric Change network to obtain a deep understanding of pollutant status in the TP. The organic carbon (OC) and elemental carbon (EC) concentrations decreased noticeably inwards from outside to inland of the TP, consistent with their emission load and also affected by transport process and meteorological condition. Urban areas, such as Kathmandu, Karachi, and Mardan, exhibited extremely high OC and EC concentrations, with low and high values occurring in the monsoon and non-monsoon seasons, respectively. However, remote regions inland the TP (e.g., Nam Co and Ngari) demonstrated much lower OC and EC concentrations. Different seasonal variations were observed between the southern and northern parts of the TP, suggesting differences in the patterns of pollutant sources and in distance from the sources between the two regions. In addition to the influence of long-range transported pollutants from the Indo-Gangetic Plain (IGP), the TP was affected by local emissions (e.g., biomass burning). The OC/EC ratio also suggested that biomass burning was prevalent in the center TP, whereas the marginal sites (e.g., Jomsom, Dhunche, and Laohugou) were affected by fossil fuel combustion from the up-wind regions. The mass absorption cross-section of EC (MACEC) at 632 nm ranged from 6.56 to 14.7 m2 g-1, with an increasing trend from outside to inland of the TP. Urban areas had low MACEC values because such regions were mainly affected by local fresh emissions. In addition, large amount of brown carbon can decrease the MACEC values in cities of South Asia. Remote sites had high MACEC values because of the coating enhancement of aerosols. Influenced by emission, transport process, and weather condition, the CA concentrations and MACEC presented decreasing and increasing trends, respectively, from outside to inland of the TP.
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Affiliation(s)
- Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Chaoliu Li
- Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qianggong Zhang
- Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Yulan Zhang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Gang Li
- Arid Meteorological Research Institute, Lanzhou Meteorological Bureau, Lanzhou, Gansu, 730000, China
| | - Chaman Gul
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Zhiyuan Cong
- Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xin Wan
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hewen Niu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Arnico K Panday
- International Centre for Integrated Mountain Development, 44700, Kathmandu, Nepal
| | | | - Zhenming Ji
- School of Atmospheric Sciences, and Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, 510275, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai, 519000, China
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Paudyal R, Kang S, Tripathee L, Guo J, Sharma CM, Huang J, Niu H, Sun S, Pu T. Concentration, spatiotemporal distribution, and sources of mercury in Mt. Yulong, a remote site in southeastern Tibetan Plateau. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:16457-16469. [PMID: 30980371 DOI: 10.1007/s11356-019-05005-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 03/26/2019] [Indexed: 06/09/2023]
Abstract
The unique geographic location of Mt. Yulong in the Tibetan Plateau (TP) makes it a favorable site for mercury (Hg) study. Various snow samples, such as surface snow, snow pit, and snowmelt water were collected from Mt. Yulong in the southeastern TP. The average concentration of Hg was found to be 37 ± 26 ng L-1 (mean ± SD), comparable to Hg concentration from other parts of TP in the same year, though it was comparatively higher than those from previous years, suggesting a possible increase of Hg concentration over the TP. The concentration of Hg was higher in the lower elevation of the glaciers possibly due to the surface melting concentration of particulates. Higher concentration of Hg was observed in the fresh snow, suggesting the possibility of long-range transportation. The average concentration of Hg from the snow pit was 1.49 ± 0.78 ng L-1, and the concentration of Hg in the vertical profile of the snow pit co-varied with calcium ion (Ca2+) supporting the fact that the portion of Hg is from the crustal origin. In addition, the principal component analysis (PCA) confirmed that the source of Hg is from the crustal origin; however, the presence of anthropogenic source in the Mt. Yulong was also observed. In surface water around Mt. Yulong, the concentration of HgT was found in the order of Lashihai Lake > Reservoirs > Rivers > Swamps > Luguhu Lake. In lake water, the concentration of HgT showed an increasing trend with depth. Overall, the increased concentration of Hg in recent years from the TP can be of concern and may have an adverse impact on the downstream ecosystem, wildlife, and human health.
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Affiliation(s)
- Rukumesh Paudyal
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China.
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
- Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
| | - Chhatra Mani Sharma
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
- Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
- Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
| | - Jie Huang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hewen Niu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
- Yulong Snow Mountain Glacier and Environmental Observation Research Station, State Key Laboratory of Cryospheric Science, Lanzhou, 730000, China
| | - Shiwei Sun
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Pu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Donggang West Rd. 320, Lanzhou, 730000, China
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Tripathee L, Guo J, Kang S, Paudyal R, Huang J, Sharma CM, Zhang Q, Chen P, Ghimire PS, Sigdel M. Spatial and temporal distribution of total mercury in atmospheric wet precipitation at four sites from the Nepal-Himalayas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 655:1207-1217. [PMID: 30577113 DOI: 10.1016/j.scitotenv.2018.11.338] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/22/2018] [Accepted: 11/23/2018] [Indexed: 06/09/2023]
Abstract
The studies on global pollutant mercury (Hg), which is of public concern due to its high toxicity and capacity to long-range transport via atmospheric circulation, is poorly characterized in wet deposition over the Nepal-Himalayas region. Therefore, in order to understand the concentration levels, spatial distribution and seasonal variation of total Hg, 333 precipitation samples were collected from south to north: Kathmandu (1314 m a.s.l.), Dhunche (2065 m a.s.l.), Dimsa (3078 m a.s.l.) and Gosainkunda (4417 m a.s.l.) characterized as urban, rural, remote forest and remote alpine sites, respectively, for over one-year period. The highest Hg concentration was found in Kathmandu comparable to the urban sites worldwide, and significantly lower concentrations at other three sites demonstrated similar levels as in rural and remote alpine sites worldwide. Higher wet deposition fluxes of 34.91 and 15.89 μg m-2 year-1 were found in Kathmandu and Dhunche respectively, due to higher precipitation amount. Clear and distinct seasonal differences were observed with higher concentrations in non-monsoon and lower values in monsoon periods due to less scavenging and high pollutant concentration loadings during the dry period. The positive correlation of Hg flux and precipitation amount with Hg concentration suggested that both precipitation amount and Hg concentration plays a vital role in Hg deposition in the central Himalayan region. Enrichment factor (EFHg) indicated that the anthropogenic emission sources play a significant role for Hg enrichment and a high ratio of EFmonsoon to EFnon-monsoon (>2.18) suggested that the anthropogenic atmospheric mercury could likely be long-range transported from south Asian regions to the Himalayas during the monsoon season. In addition, our results showed that the major ionic compositions (e.g., SO42-, NO3-, NH4+, K+, Ca2+) could influence Hg concentration in wet precipitation. The anthropogenic sources of Hg such as biomass and fossil fuel combustion, crustal aerosols may contribute to the Hg concentration in wet precipitation over the central Himalayas.
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Affiliation(s)
- Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China.
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rukumesh Paudyal
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Huang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Chhatra Mani Sharma
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal; Central Department of Environmental Science, Tribhuvan University, Kathmandu, Nepal
| | - Qianggong Zhang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China
| | - Prakriti Sharma Ghimire
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou 730000, China; Himalayan Environment Research Institute (HERI), Kathmandu, Nepal
| | - Madan Sigdel
- Central Department of Hydrology and Meteorology, Tribhuvan University, Kathmandu, Nepal
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Characterizing Emissions from Agricultural Diesel Pumps in the Terai Region of Nepal. ATMOSPHERE 2019. [DOI: 10.3390/atmos10020056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Diesel irrigation pumps are a source of air pollution in the Indo-Gangetic Plain (IGP). The environmental implications of these pumps are often overlooked and very rarely addressed in the IGP. Few studies in the past have estimated the amount of diesel consumed by irrigation pumps in the IGP or other proxy variables to estimate the amount of emissions. A considerable amount of uncertainty remains in calculating emission factors (EF) using real-time measurements. We measured pollutants from nine diesel irrigation pumps in the southern ‘Terai’ belt of Nepal. Fuel-based EF were then estimated using the carbon mass balance method. The average EF for fine particulate matter (PM2.5), CO2, CO and black carbon (BC) were found to be 22.11 ± 3.71, 2218.10 ± 26.8, 275 ± 17.18 and 2.54 ± 0.71 g/L, respectively. Depending upon the pump characteristics (age, design, make, hours used, etc.) and fuel mixtures, the EF of PM2.5, BC and CO had larger inter-variability. This study provides estimates for an under-represented source of ambient air pollution which will assist in the development of better emission inventories and informed policy making.
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Yang J, Kang S, Ji Z, Yang S, Li C, Tripathee L. Vital contribution of residential emissions to atmospheric fine particles (PM 2.5) during the severe wintertime pollution episodes in Western China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 245:519-530. [PMID: 30466071 DOI: 10.1016/j.envpol.2018.11.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/15/2018] [Accepted: 11/08/2018] [Indexed: 06/09/2023]
Abstract
To mitigate severe wintertime pollution events in Western China, identifying the source of atmospheric fine particles with an aerodynamic diameter of ≤2.5 μm (PM2.5) is a crucial step. In this study, we first analyzed the meteorological and emission factors that caused a considerable increase in the PM2.5 concentration in December 2016. This severe pollution episode was found to be related with unfavorable meteorological conditions and increased residential emissions. The WRF-Chem simulations were used to calculate the residential contribution to PM2.5 through a hybrid source apportionment method. From the validation that used grid data and in situ observations in terms of meteorological elements, PM2.5 and its compounds, the simulated results indicated that the residential sector was the largest single contributor to the PM2.5 concentration (60.2%), because of its predominant contributions to black carbon (BC, 62.1%) and primary organic aerosol (POA, 86.5%), with these two primary components accounting for 70.7% of the PM2.5 mass. Compared with the remote background (RB) region covering the central part of the Tibetan Plateau, the residential sector contributed 11.3% more to PM2.5 in the highly populated mega-city (HM) region, including the Sichuan and Guanzhong Basins, due to greater contribution to the concentrations of primary PM2.5 components. As the main emission source of sulfur dioxide (SO2), nitrogen oxides (NOx), and secondary organic aerosol (SOA), the industrial sector was the second largest contributor to the PM2.5 concentration in the HM region. However, in the RB region, the dominating emissions of NOx, SOA, and BC were from the transport sector; thus, it was the next largest contributor to total PM2.5. An evaluation of the emission control experiment suggested that mitigation strategies that reduce emissions from residential sources can effectively reduce the PM2.5 concentration during heavy pollution periods.
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Affiliation(s)
- Junhua Yang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 73000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 73000, China.
| | - Zhenming Ji
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Sixiao Yang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, 510275, China
| | - ChaoLiu Li
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 73000, China
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Rehman Qaisar FU, Zhang F, Pant RR, Wang G, Khan S, Zeng C. Spatial variation, source identification, and quality assessment of surface water geochemical composition in the Indus River Basin, Pakistan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:12749-12763. [PMID: 29470753 DOI: 10.1007/s11356-018-1519-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/08/2018] [Indexed: 05/12/2023]
Abstract
The Indus River Basin (IRB) with an area of 139,202 km2 is the lifeline river basin of Pakistan. An intensive study was conducted in six subcatchments of the IRB with five in the Upper Indus Basin (UIB) and one of the Lower Indus Basin (LIB; between Tarbela Dam and Panjand), i.e., the Gilgit River Basin (UIB-I), Hunza River Basin (UIB-II), UIB-III, UIB-IV and UIB-V, and LIB. A total of 84 surface water samples were collected from main stream and tributaries from June to August, 2016. The pH, electric conductivity (EC), and total dissolved solids (TDS) were measured in situ, whereas major ions (Ca2+, Mg2+, K+, Na+, Cl-, SO42-, and NO3-) and Si were analyzed in the laboratory. The results exhibited alkaline pH (8.55 ± 0.20) with diverse TDS (114.69 ± 77.65 mg L-1) and ion concentrations that were characterized primarily by the Ca-Mg-HCO3 type in the whole basin. The average TDS in the UIB and LIB were 93.99 ± 39.73 and 181.67 ± 167.82 mg L-1, respectively, under the influence of the arid to semi-arid climatic conditions and relatively higher anthropogenic interference in LIB compared to the UIB. The order of dominant major cations was different in the UIB and LIB, reflecting the diverse nature of geological formation. Gibbs plot, mixing diagrams, and ionic ratios were used to identify the controlling mechanism of river geochemistry in the IRB as carbonate weathering in general with different degrees of silicate weathering and minor contribution by evaporite dissolution. In addition, principal component/factor analysis also indicated that the major sources of dissolved loads in the basin are carbonates followed by silicates. Significant influences of silicate minerals were observed in the LIB, and there was a large contribution of evaporites in the UIB-II, UIB-III, and LIB. The suitability assessment showed that the river water fits the WHO permissible limits for drinking purposes from the perspective of major ions, whereas for irrigation purposes, most of the samples exhibited excellent and good levels except for a couple of permissible and doubtful levels from the Sawan and Deratang tributaries in the LIB, which may deteriorate the quality of soil and degrade the water quality downstream.
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Affiliation(s)
- Faizan Ur Rehman Qaisar
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Department of Earth Sciences COMSATS Institute of Information Technology, Abbottabad, Pakistan
| | - Fan Zhang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China.
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Ramesh Raj Pant
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Central Department of Environmental Science, Tribhuvan University, Kirtipur, Nepal
| | - Guanxing Wang
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sardar Khan
- Department of Environmental Sciences, University of Peshawar, Peshawar, Pakistan
| | - Chen Zeng
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
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