Lumbini is a world heritage site located in the southern plains region of Nepal, and is regarded as a potential site for evaluating transboundary air pollution due to its proximity to the border with India. In this study, 82 aerosol samples were collected between April 2013 and July 2014 to investigate the levels of particulate-bound mercury (PBM) and the corresponding seasonality, sources, and influencing factors. The PBM concentration in total suspended particulate (TSP) matter ranged from 6.8 pg m⁻³ to 351.7 pg m⁻³ (mean of 99.7 ± 92.6 pg m⁻³), which exceeded the ranges reported for remote and rural sites worldwide. The Hg content (PBM/TSP) ranged from 68.2 ng g⁻¹ to 1744.8 ng g⁻¹ (mean of 446.9 ± 312.7 ng g⁻¹), indicating anthropogenic enrichment. The PBM levels were higher in the dry season (i.e., winter and the pre-monsoon period) than in the wet season (i.e., the monsoon period). In addition, the δ²⁰²Hg signature indicated that waste/coal burning and traffic were the major sources of Hg in Lumbini during the pre-monsoon period. Meanwhile, precipitation occurring during photochemical processes in the atmosphere may have been responsible for the observed Δ¹⁹⁹Hg values in the aerosol samples obtained during the monsoon period. The PBM concentration was influenced mostly by the resuspension of polluted dust during dry periods and crop residue burning during the post-monsoon period. The estimated PBM deposition flux at Lumbini was 15.7 μg m⁻² yr⁻¹. This study provides a reference dataset of atmospheric PBM over a year, which can be useful for understanding the geochemical cycling of Hg in this region of limited data.

蓝毗尼是位于尼泊尔南部平原地区的世界遗产，由于靠近印度边境，被视为评估跨界空气污染的潜在地点。本研究于 2013 年 4 月至 2014 年 7 月期间收集了 82 个气溶胶样本，以调查颗粒物结合汞 (PBM) 的水平以及相应的季节性、来源和影响因素。总悬浮颗粒物 (TSP) 物质中的 PBM 浓度范围为 6.8 pg m ^-3至 351.7 pg m ^-3（平均值为 99.7 ± 92.6 pg m ^-3），超出了全球偏远和农村地区报告的范围。汞含量 (PBM/TSP) 范围从 68.2 ng g ^-1到 1744.8 ng g ^-1（平均值为 446.9 ± 312.7 ng g ^-1），表明人为富集。旱季（即冬季和季风前期）的 PBM 水平高于雨季（即季风期）。此外，δ ²⁰² Hg 特征表明，在季风前时期，垃圾/煤炭燃烧和交通是蓝毗尼的主要汞来源。同时，大气光化学过程中发生的降水可能是观测到的 Δ ¹⁹⁹在季风期间获得的气溶胶样品中的 Hg 值。PBM 浓度主要受干旱期污染粉尘的再悬浮和后季风期作物残留物燃烧的影响。蓝毗尼的估计PBM 沉积通量为15.7 μg m ^-2 yr ^-1。本研究提供了一年多的大气 PBM 参考数据集，有助于了解该地区数据有限的汞地球化学循环。