The ecological situation in New York City served as the starting point, whose "cleanliness index" traditionally stands at 100 points.
According to NEWSru.co.il, first place in the ranking went to Baku (Azerbaijan), which was awarded an index of 27.6. Journalists note that the reason for the unfavorable environmental situation in the city was the oil extraction industry. Among other cities of the former Soviet Union, Almaty (9th place) and Moscow (14th place) also made it onto the list.
The cleanest city in the world was recognized as Calgary, a major industrial center in Canada. The cleanliness index of this city with a developed industrial industry was 131.7 points.