The assessment of near-surface air pollutants has been done at an urban site, Varanasi, in the central Indo-Gangetic Basin (IGB) during July 2014 to June 2018. The various pollutants, such as particulate matters of diameter less than 2.5 μm (PM_2.5) and less than 10 μm (PM₁₀), sulphur dioxide (SO₂), nitrogen dioxide (NO₂) and ozone (O₃) were obtained from the Central Pollution Control Board (CPCB). The annual mean mass concentrations of PM₁₀, PM_2.5, SO₂, NO₂ and O₃ were 239 ± 128, 123 ± 89, 17.5 ± 9.6, 52 ± 35 and 30 ± 14 μg m⁻³, respectively. The concentrations of PM₁₀, PM_2.5 and NO₂ were found to be higher than their National Ambient Air Quality Standards (NAAQS) by a factor of 4, 3.1 and 1.3, respectively; however, SO₂ and O₃ were always well within their standard limits. Seasonally, all the pollutants, except ozone were found to be the highest during the postmonsoon and winter seasons. The sources of pollutants have been widely characterized at this site and in general over the IGB. Further, an attempt has been made, for the first time, to elucidate the possible transport pathways of the measured pollutants, especially PM_2.5 to downwind of the station using concentration weight trajectory (CWT) analyses with the forward air mass trajectories. The results show significant potential for transport of PM_2.5 (~ 65%) from the IGB to downwind over the northern Bay of Bengal region, with more pronounced during the winter season (~ 95%). These results underline the importance of IGB pollution outflow towards downwind continental and marine regions, which can have significant climatic impacts.

2014年7月至2018年6月，已在印度中部恒河盆地中部（IGB）的瓦拉纳西市区进行了近地表空气污染物的评估。各种污染物，例如直径小于2.5μm的颗粒物（从中央污染控制委员会（CPCB）获得了PM _2.5）和小于10μm（PM ₁₀）的二氧化硫（SO ₂），二氧化氮（NO ₂）和臭氧（O ₃）。PM ₁₀，PM _2.5，SO ₂，NO ₂和O ₃的年平均质量浓度为239±128、123±89、17.5±9.6、52±35和30±14μgm ^-3， 分别。发现PM ₁₀，PM _2.5和NO ₂的浓度分别比其国家环境空气质量标准（NAAQS）高4倍，3.1倍和1.3倍。但是，SO ₂和O ₃始终在其标准范围内。在季节上，除臭氧外，所有污染物在季风季节和冬季均最高。污染物的来源已在该地点和整个IGB上得到了广泛表征。此外，首次尝试阐明被测污染物尤其是PM _2.5的可能的传输途径。使用集中重量轨迹（CWT）分析和向前的空气质量轨迹来对站点进行顺风。结果表明，PM _2.5（〜65％）从IGB到孟加拉湾北部湾的顺风运输的潜力很大，在冬季尤为明显（〜95％）。这些结果强调了IGB污染流向顺风的大陆和海洋地区的重要性，这可能会对气候产生重大影响。