世界卫生组织称它是“欧洲大陆最大的环境健康风险 ” ， 据估计90%的欧洲公民暴露在超出世卫组织空气质量指导标准的室外污染中。
The World Health Organization has called it the continent’s “single largest environmental health risk,” estimating that 90% of Europe’s citizens are exposed to outdoor pollution that exceeds WHO air-quality guidelines.