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.

中文翻译：

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在印度恒河平原的典型农村地区，严重的空气污染和光吸收颗粒的特征。

2013年4月至2016年3月在蓝毗尼收集了总悬浮颗粒（TSP），以更好地了解严重污染的印度-恒河平原（IGP）农村地区的碳质气溶胶（CA）浓度，组成和来源及其吸光特性。在蓝毗尼特别是在冬季和季风后期间，观察到极高的TSP（203.9±109.6μgm-3），有机碳（OC 32.1±21.7μgm-3），元素碳（EC 6.44±3.17μgm-3）浓度。季节，反映了排放源和天气条件的综合影响。在TSP中，SO42-（7.34±4.39μgm-3）和Ca2 +（5.46±5.20μgm-3）是最主要的阴离子和阳离子。这些成分与在南亚和东亚市区观察到的成分相当，但明显高于喜马拉雅山和青藏高原偏远地区的成分，表明研究区域的空气污染严重。包括工业，车辆排放和生物质燃烧在内的各种燃烧活动是造成高污染物浓度的主要原因。OC / EC比率的变化进一步表明，农残燃烧等生物量对CA的贡献很大，尤其是在非季风季节。EC（MACEC）和水溶性有机碳（MACWSOC）的平均质量吸收截面分别为7.58±3.39和1.52±0.41 m2 g-1，这表明蓝毗尼的CA主要受局部排放的影响。生物质燃烧增加，MACEC减少；而，在非季风季节可能会导致MACWSOC升高。此外，粉尘是导致季风前季节MACWSOC升高的重要因素。