Influence of Saharan dust outbreaks and carbon content on oxidative potential of water-soluble fractions of PM2.5 and PM10
Influence of Saharan dust outbreaks and carbon content on oxidative potential of water-soluble fractions of PM2.5 and PM10
复制标题
DOI：
10.1016/j.atmosenv.2017.05.021
复制
发表时间：
2017-08-01
影响因子：
5
通讯作者：
Contini, Daniele
中科院分区：
文献类型：
--
作者：
Chirizzi, Daniela;Cesari, Daniela;Contini, Daniele
暴露于大气颗粒物（PM）会对健康产生不利影响，尽管对确切的毒性机制仍知之甚少。一些研究表明，大量的PM健康影响可能是由于周围颗粒的氧化电位（OP）导致高浓度的活性氧（ROS）。已在几个地点调查了特定人为源（如道路交通、生物质燃烧和工业排放）对OP的贡献。然而，有关自然源OP的信息很少，并且没有有关地中海地区撒哈拉沙尘爆发（SDO）期间OP的数据。这项工作使用的α-细胞DTT（二硫苏糖醇）分析，以评估OP的水溶性部分的PM2.5和PM10收集在城市背景的网站在南部意大利。OP值在三组样本进行了比较：标准的特点是浓度类似于年平均值;高碳样品与燃烧源（主要是道路交通和生物质燃烧）和SDO事件。DTT活动归一化采样的空气体积（DTTv），代表个人暴露，和归一化收集的气溶胶质量（DTTM），代表源的具体特征，进行了研究。对于高PM浓度，DTTv较大。DTTv与次生有机碳浓度有很好的相关性。与粗粒级PM2.5-10相比，发现PM2.5的DTTv响应增加。高碳含量样品的DTTv较大，但在SDO事件期间与标准样品的DTTv在统计学上相当。与PM10相比，PM2，5的DTTM更大，并且在SDO事件期间两个尺寸级分之间的相对差异最大化。这表明，撒哈拉沙尘平流是一个自然的颗粒源，具有较低的特定OP相对于其他来源作用于该地区（水溶性部分）。在流行病学研究中应考虑OP，以评估受撒哈拉沙尘平流造成的高污染事件影响的地区与ROS相关的潜在健康风险。(C)2017爱思唯尔有限公司版权所有
Exposure to atmospheric particulate matter (PM) leads to adverse health effects although the exact mechanisms of toxicity are still poorly understood. Several studies suggested that a large number of PM health effects could be due to the oxidative potential (OP) of ambient particles leading to high concentrations of reactive oxygen species (ROS). The contribution to OP of specific anthropogenic sources like road traffic, biomass burning, and industrial emissions has been investigated in several sites. However, information about the OP of natural sources are scarce and no data is available regarding the OP during Saharan dust outbreaks (SDO) in Mediterranean regions. This work uses the a-cellular DTT (dithiothreitol) assay to evaluate OP of the water-soluble fraction of PM2.5 and PM10 collected at an urban background site in Southern Italy. OP values in three groups of samples were compared: standard characterised by concentrations similar to the yearly averages; high carbon samples associated to combustion sources (mainly road traffic and biomass burning) and SDO events. DTT activity normalised by sampled air volume (DTTv), representative of personal exposure, and normalised by collected aerosol mass (DTTM), representing source-specific characteristics, were investigated. The DTTv is larger for high PM concentrations. DTTv is well correlated with secondary organic carbon concentration. An increased DTTv response was found for PM2.5 compared to the coarse fraction PM2.5-10. DTTv is larger for high carbon content samples but during SDO events is statistically comparable with that of standard samples. DTTM is larger for PM2,5 compared to PM10 and the relative difference between the two size fractions is maximised during SDO events. This indicates that Saharan dust advection is a natural source of particles having a lower specific OP with respect to the other sources acting on the area (for water-soluble fraction). OP should be taken into account in epidemiological studies to evaluate the potential health risks associated to ROS in regions affected by high pollution events due to Saharan dust advection. (C) 2017 Elsevier Ltd. All rights reserved.