Urban areas are major consumers of environmental resources and thus often place unsustainable demands on natural resources. As half of the world’s population (55%) lives in urban areas, the environmental degradation produced by cities threatens the health and quality of life of a fair share of the world’s population. For these reasons, progress towards sustainable urban development must be monitored and measured through suitable indicators. With reference to the assessment of air quality as a specific dimension of environmental quality in urban areas, existing studies have introduced various methodologies that mostly focus on objective measures (typically, exposure to outdoor air pollutants) while neglecting measures based on individual perceptions. Our goal is to contribute to filling this gap. To this end, we explore the relationship between objective and subjective measures of urban air quality in European countries. While the objective indicator is based on concentrations of PM2.5, our subjective indicator is reconstructed from individual perceptions collected through the European Union Statistics on Income and Living Conditions (EU-SILC) sample survey. Finally, through a cluster analysis, we classify the countries into homogeneous groups based on the values of these indicators. Our analysis reveals several differences in the country rankings according to the two indicators. For one group of countries, both approaches converge, thus leading to more definitive conclusions. For other countries, the mismatch between the two indicators suggests that either approach alone is not able to capture the full picture on air quality in urban environments.

城市地区是环境资源的主要消费者，因此经常对自然资源提出不可持续的需求。世界人口的一半（55％）居住在城市地区，城市造成的环境恶化威胁着相当一部分世界人口的健康和生活质量。由于这些原因，必须通过适当的指标监测和衡量城市可持续发展的进展。关于将空气质量作为城市环境质量的一个特定维度进行评估，现有研究引入了各种方法，这些方法主要侧重于客观措施（通常是暴露于室外空气污染物），而忽略了基于个人看法的措施。我们的目标是为填补这一空白做出贡献。为此，我们探索了欧洲国家城市空气质量的客观和主观衡量之间的关系。虽然客观指标是基于PM2.5的浓度，但我们的主观指标是根据通过欧盟收入和生活状况统计（EU-SILC）抽样调查收集的个人看法重构的。最后，通过聚类分析，我们根据这些指标的值将国家分为同类。我们的分析根据这两个指标揭示了国家排名的一些差异。对于一组国家，这两种方法趋于一致，从而得出更明确的结论。对于其他国家，这两个指标之间的不匹配表明仅靠这两种方法都无法全面了解城市环境中的空气质量。