In order to investigate particulate matter characteristics in the urban area of Naples, South of Italy, PM10 and PM2.5 chemical composition and properties were determined; in particular, ionic composition (Na+, K+, NH4+, Mg2+, Ca2+, HCOO-, CH3COO−, Cl−, NO2−, NO3−, SO42−, C2O42−) and concentration of specific metals (Pb, Cd, Cu and Zn) were evaluated in association with an air masses trajectories study. Information on major ions was used to conduct the ionic balance and to evaluate sea salt and non-sea salt contributions; furthermore, the study on metals concentration allowed to distinguish the contribution of anthropic sources while their chemical behaviour (solubility and leachability) was considered in order to highlight the presence of different chemical forms. In the period of interest (June 2015), daily averages PM concentrations were below the limit of 25 μg/m3 for PM2.5 and 50 μg/m3for PM10; moreover, for both fractions, the most abundant ionic species was SO42−followed by NO3−. Ionic balance indicated that non-sea salt contribution accounted for the great part of Ca2+, SO42− and K+ while secondary inorganic aerosol accounted for about 5% of total ionic fraction. As expected, the most abundant metal was zinc (about 41 ng/m3 and 44 ng/m3in PM2.5 and PM10, respectively), while cadmium, copper and lead were at very low concentrations, in the range of 0.01–0.47 ng/m3; leachability reached values of 40% for copper in both PM fractions, in contrast with zinc that showed the lowest leachability, corresponding to 6% for PM2.5 fraction. The study on air masses trajectories indicated a change on ionic composition and chemical properties, varying from a condition with air masses coming from Eastern Europe, characterised also by higher concentrations of both PM2.5 and PM10, a prevalence of secondary aerosol and metals showing minor solubility and leachability, to a condition with air masses coming from North-west region, with characteristics opposed to the previous ones.

中文翻译：

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那不勒斯市区的PM2.5和PM10：气团起源的化学成分、化学性质和影响

为了调查意大利南部那不勒斯市区的颗粒物特征，确定了 PM10 和 PM2.5 的化学成分和特性；特别是离子组成（Na+、K+、NH4+、Mg2+、Ca2+、HCOO-、CH3COO-、Cl-、NO2-、NO3-、SO42-、C2O42-）和特定金属（Pb、Cd、Cu 和 Zn）的浓度) 结合气团轨迹研究进行了评估。主要离子的信息用于进行离子平衡并评估海盐和非海盐的贡献；此外，对金属浓度的研究可以区分人为来源的贡献，同时考虑它们的化学行为（溶解度和浸出性），以突出不同化学形式的存在。在利息期间（2015年6月），每日平均 PM 浓度低于 PM2.5 的 25 μg/m3 和 PM10 的 50 μg/m3 的限值；此外，对于这两个部分，最丰富的离子种类是 SO42-，其次是 NO3-。离子平衡表明非海盐贡献占Ca2+、SO42-和K+的大部分，而二次无机气溶胶约占总离子部分的5%。正如预期的那样，最丰富的金属是锌（在 PM2.5 和 PM10 中分别约为 41 ng/m3 和 44 ng/m3），而镉、铜和铅的浓度非常低，范围为 0.01-0.47 ng/m3立方米；两种 PM 组分中铜的可浸出性均达到 40%，而锌的可浸出性最低，对应 PM2.5 组分的 6%。对气团轨迹的研究表明离子组成和化学性质发生了变化，