Barnaba Francesca, Alvan Romero Nancy, Bolignano Andrea, Basart Sara, Renzi Matteo, Stafoggia Massimo
National Research Council, Institute of Atmospheric Sciences and Climate (CNR-ISAC), Rome, Italy.
National Research Council, Institute of Atmospheric Sciences and Climate (CNR-ISAC), Rome, Italy; University of Rome 'La Sapienza', Department of Information Engineering, Electronics and Telecommunications (DIET), Rome, Italy(1).
Environ Int. 2022 May;163:107204. doi: 10.1016/j.envint.2022.107204. Epub 2022 Mar 30.
Desert dust storms pose real threats to air quality and health of millions of people in source regions, with associated impacts extending to downwind areas. Europe (EU) is frequently affected by atmospheric transport of desert dust from the Northern Africa and Middle East drylands. This investigation aims at quantifying the role of desert dust transport events on air quality (AQ) over Italy, which is among the EU countries most impacted by this phenomenon. We focus on the particulate matter (PM) metrics regulated by the EU AQ Directive. In particular, we use multiannual (2006-2012) PM10 records collected in hundreds monitoring sites within the national AQ network to quantify daily and annual contributions of dust during transport episodes. The methodology followed was built on specific European Commission guidelines released to evaluate the natural contributions to the measured PM-levels, and was partially modified, tested and adapted to the Italian case in a previous study. Overall, we show that impact of dust on the yearly average PM10 has a clear latitudinal gradient (from less than 1 to greater than 10 µg/m going from north to south Italy), this feature being mainly driven by an increased number of dust episodes per year with decreasing latitude. Conversely, the daily-average dust-PM10 (≅12 µg/m) is more homogenous over the country and shown to be mainly influenced by the site type, with enhanced values in more urbanized locations. This study also combines the PM10 measurements-approach with geostatistical modelling. In particular, exploiting the dust-PM10 dataset obtained at site- and daily-resolution over Italy, a geostatistical, random-forest model was set up to derive a daily, spatially-continuous field of desert-dust PM10 at high (1-km) resolution. This finely resolved information represent the basis for a follow up investigation of both acute and chronic health effects of desert dust over Italy, stemming from daily and annual exposures, respectively.
沙漠沙尘暴对源区的空气质量和数百万人的健康构成了切实威胁，其相关影响还会延伸至下风地区。欧洲（欧盟）经常受到来自北非和中东旱地的沙漠沙尘大气传输的影响。本调查旨在量化沙漠沙尘传输事件对意大利空气质量（AQ）的作用，意大利是欧盟国家中受这一现象影响最为严重的国家之一。我们关注欧盟空气质量指令所规定的颗粒物（PM）指标。具体而言，我们使用在国家空气质量监测网络内数百个监测站点收集的多年（2006 - 2012年）PM10记录，来量化沙尘传输事件期间每日和每年的沙尘贡献。所采用的方法基于欧盟委员会发布的用于评估对实测PM水平自然贡献的特定指南，并在先前的一项研究中针对意大利情况进行了部分修改、测试和调整。总体而言，我们表明沙尘对年平均PM10的影响具有明显的纬度梯度（从意大利北部的小于1微克/立方米到南部的大于10微克/立方米），这一特征主要是由每年沙尘事件数量随纬度降低而增加所驱动的。相反，每日平均沙尘 - PM10（约为12微克/立方米）在全国更为均匀，且显示主要受站点类型影响，在城市化程度较高的地区数值更高。本研究还将PM10测量方法与地统计建模相结合。特别是，利用在意大利以站点和每日分辨率获得的沙尘 - PM10数据集，建立了一个地统计随机森林模型，以高分辨率（1公里）得出每日空间连续的沙漠沙尘PM10场。这些精细解析的信息分别代表了对意大利沙漠沙尘每日和每年暴露所产生的急性和慢性健康影响进行后续调查的基础。
