High sulfur emissions in the Central Andes have in the past been attributed to active volcanoes and numerous copper smelting facilities in the region. This study evaluates the contribution of these sources on Arequipa, Peru through an evaluation of aerosol sulfate δ³⁴S values and water-soluble ions (WSI). The anthropogenic and natural sources of particulate pollution were determined by aerosol filter sampling from four different locations (urban, suburban, industrial, and rural) providing a view of the spatial variability of aerosols within the city. Sulfate (avg. 2.97 μm/m³) is the most abundant ion species in the aerosols sampled contributing on average 20% of the molar mass. Ion composition profiles between sampling sites are very similar indicating common sources and high contributions of mobilized local surface salt to the aerosols in this desert region. The regional atmospheric chemistry model (RACM) 0-D run for the area confirms that emissions from fuel combustion sources alone cannot account for the high concentrations of sulfate observed. A combination of the RACM results, WSI data, and a Bayesian δ³⁴S isotope mixing model determined that the majority of aerosol sulfates in the area are from mineral dust adding to fossil fuel combustion sources. Mineral dust entrainment in the region is likely elevated by the close proximity of open-pit mining and unpaved roads near the city. Marine organic aerosols and smelting located along the Pacific contribute little to Arequipa’s aerosol sulfate concentration. While the influence of volcanic sulfate (9% on average) is low, overall natural sulfate (dust, volcanic, and DMS) accounts for 43% of the aerosol sulfate. Therefore, even though the local environment creates high sulfate background levels, a reduction of sulfate aerosol pollution would be possible if fossil fuel emissions were reduced.

过去，安第斯中部地区的高硫排放归因于该地区活跃的火山和众多的铜冶炼设施。本研究评估对秘鲁阿雷基帕这些源通过气雾剂硫酸盐δ的评估的贡献^34个的价值观和水溶性离子（WSI）。颗粒物污染的人为和自然来源是通过从四个不同地点（城市，郊区，工业和农村）进行气溶胶过滤器采样确定的，从而了解了城市中气溶胶的空间变异性。硫酸盐（平均2.97μm/ m ³）是采样的气溶胶中最丰富的离子种类，平均贡献了20％的摩尔质量。采样点之间的离子组成特征非常相似，表明该沙漠地区的常见来源和动员的局部表面盐对气溶胶的高度贡献。在该地区运行的区域大气化学模型（RACM）0-D证实，仅来自燃料燃烧源的排放不能解释所观测到的高浓度硫酸盐。所述RACM结果的组合，WSI数据，以及贝叶斯δ ³⁴同位素混合模型确定该地区的大部分气溶胶硫酸盐来自矿物粉尘，并添加到化石燃料燃烧源中。该地区附近露天矿和未铺砌道路的靠近可能会增加该地区的矿物粉尘夹带。太平洋沿岸的海洋有机气溶胶和冶炼对阿雷基帕的气溶胶硫酸盐浓度影响不大。尽管火山硫酸盐（平均为9％）的影响较小，但总的天然硫酸盐（粉尘，火山灰和DMS）占硫酸盐气溶胶的43％。因此，即使当地环境产生了很高的硫酸盐本底水平，但如果减少化石燃料的排放，也有可能减少硫酸盐气溶胶的污染。