10 Cleanest Countries In The World In 2023

Page 6 of 10

5. Switzerland 

Composite Ranking: 5

Air Quality PM2.5 concentration (μg/m³): 9

Waste Management Score: 76.4% 

Wastewater Treatment Score: 97% 

In 2023, Switzerland stands as one of the cleanest nations in the world because of its exceptional air and water quality metrics. The country’s average PM2.5 concentration is 9 μg/m³, while its wastewater management infrastructure has resulted in a remarkable treatment efficacy of 97%.

Page 6 of 10