particulate matter

Particulate matter from vehicle emissions is a major contributor to urban air pollution and respiratory disease.来自车辆尾气的颗粒物是城市空气污染和呼吸系统疾病的主要成因。

Standards limiting particulate matter concentrations in ambient air have been tightened in many countries.许多国家已经收紧了限制环境空气中颗粒物浓度的标准。