based on daily values

<div style='text-align: left; text-indent: -48px;'><p><font size='2'>          <span>The map shows annual mean concentrations of Particulate Matter (PM10) in Europe based on daily averages with at least 75% of valid measurements, in µg/m3 </span></font><br /><span style='overflow: auto;'><span><span style='overflow: auto;'><span><font size='2'>(source: EEA, AirBase v.8 &amp; AQ e-Reporting)</font></span></span></span></span></p><p><font size='2'>          </font><span style='overflow: auto;'><span><span style='overflow: auto;'><span><font size='2'></font></span></span></span></span><font size='2'>Thresholds used in the map for annual values [µg/m3]:</font></p></div><p></p> <p></p><p><font size='2'>≤ 20: (20 μg/m3, as set out in the WHO air quality guideline for PM10)</font></p><p><font size='2'>&gt; 20 ≤ 31: (31 μg/m3, a statistically derived level corresponding to the 24‑hour limit value, as set out in the Air Quality Directive, 2008/50/EC)</font></p><p><font size='2'>&gt; 31 ≤ 40: (40 μg/m3, limit value as set out in the Air Quality Directive, 2008/50/EC)</font></p><p><font size='2'>&gt; 40 ≤ 50<br /></font></p><p><font size='2'>&gt; 50</font></p><p><font size='2'>Source: </font><a href='http://www.eea.europa.eu/data-and-maps/data/airbase-the-european-air-quality-database-8' target='_blank' rel='nofollow ugc noopener noreferrer'>AirBase v.<span style='color: rgb(68, 68, 68);'><font size='2'>8</font></span></a><font size='2'> &amp; <a href='http://www.eea.europa.eu/data-and-maps/data/aqereporting' target='_blank' rel='nofollow ugc noopener noreferrer'>AQ e-Reporting</a></font></p><p><font size='2'>AirBase is the European air quality database maintained by the EEA through its European topic centre on Air pollution and Climate Change mitigation. It contains air quality monitoring data and information submitted by participating countries throughout Europe.<br /><br />The air quality database consists of a multi-annual time series of air quality measurement data and statistics for a number of air pollutants. It also contains meta-information on those monitoring networks involved, their stations and their measurements.<br /><br />The database covers geographically all EU Member States, the EEA member countries and some EEA collaborating countries. The EU Member States are bound under Decision 97/101/EC to engage in a reciprocal exchange of information (EoI) on ambient air quality. The EEA engages with its member and collaborating countries to collect the information foreseen by the EoI Decision because air pollution is a pan European issue and the EEA is the European body which produces assessments of air quality, covering the whole geographical area of Europe.</font></p>

本地图展示欧洲地区可吸入颗粒物（Particulate Matter, PM10）的年平均浓度，数据基于日均浓度计算，且有效观测占比不低于75%，单位为微克每立方米（µg/m³）
（数据来源：欧洲环境署（European Environment Agency, EEA）、AirBase v.8 及 AQ e-Reporting）

本地图所采用的年浓度阈值（单位：µg/m³）如下：

≤20：（20 µg/m³，符合世界卫生组织（World Health Organization, WHO）制定的PM10空气质量指南标准）
20<浓度≤31：（31 µg/m³，为基于统计推导得出的24小时限值，符合《2008/50/EC号空气质量指令》规定）
31<浓度≤40：（40 µg/m³，为《2008/50/EC号空气质量指令》规定的限值）
40<浓度≤50
浓度>50

数据来源：AirBase v.8 与 AQ e-Reporting

AirBase为欧洲环境署（EEA）依托其空气污染与气候变化减缓欧洲主题中心维护的欧洲空气质量数据库，收录了欧洲各国参与监测机构提交的空气质量监测数据与相关信息。
该空气质量数据库包含多种空气污染物的多年度监测时间序列数据与统计资料，同时收录了相关监测网络、监测站点及监测活动的元数据。
该数据库的覆盖范围涵盖所有欧盟成员国、EEA成员国及部分合作成员国。根据《97/101/EC号决定》，欧盟成员国需就环境空气质量开展信息互换（Exchange of Information, EoI）。鉴于空气污染是全欧洲共同面临的问题，且EEA是负责开展全欧洲范围空气质量评估的欧洲机构，因此EEA与其成员国及合作成员国协作，收集《信息互换决定》规定的相关数据。