pollutant concentration

例句：

1. 1.The city's air quality has improvedsignificantly since the implementation of stricter pollutioncontrol measures.
   自从实施更严格的污染控制措施以来，城市的空气质量已经显著改善。
2. 2. Thestudy found that high levels of pollutants in the water can have serious healtheffects on humans.
   研究发现，水中高浓度的污染物对人类健康有严重的影响。
3. 3. The governmentis working to reduce the concentration of pollutants in the environment.
   政府正在努力减少环境中污染物的浓度。