Top ten cleanest countries in the world?

1. Switzerland

2. Denmark

3. Netherlands

4. Iceland

5. Sweden

6. Norway

7. Finland

8. New Zealand

9. Canada

10. Australia

Factors that contribute to cleanliness in these countries include effective waste management practices, robust environmental regulations, high levels of public awareness and participation in environmental protection, well-functioning public transportation systems that reduce air pollution, and strong commitment from government and businesses to sustainability.