Cleanest cities in the world revealed... as pollution-hit London does not make it into top 50

London has failed to make a list of the top 50 cleanest cities in the world.

The data on the most hygienic cities in the world was release as part of the annual Mercer Quality of Life survey – which ranked London in 41st place for overall satisfaction.

But, in separate findings which took into account a city’s sanitation for the first time, the UK capital slipped further down the list and was ranked joint 67th along with Chicago and Paris.

The Mercer survey said a city’s sanitation ranking was based on analysis of air pollution as well as waste removal and sewage infrastructure, levels of infectious disease, and water availability and quality.

It said all were considered “important aspects of a city’s attractiveness for both talent and businesses”.

London’s sanitation performance was in line with the fact that the city’s overall ranking had slipped for the third year running due to “persistent air pollution and traffic congestion”.

Kate Fitzpatrick, Mercer's Global Mobility Practice Leader for the UK and Ireland, said: "London - the highest ranked UK city - scores top marks in areas like access to public transport, and the variety and quality of theatres and restaurants, but has lower scores for air pollution and traffic congestion."

The survey added that London was further down the rankings than other European cities like Vienna, Munich, Stockholm, Olso and Lisbon because of “persistent issues with traffic congestion and air pollution.”

Honolulu topped the City Sanitation ranking, followed by Helsinki and Ottawa in joint second.

The bottom places were filled by Dhaka, the capital of Bangladesh, and Port au Prince, the capital of Haiti, which were ranked at 230 and 231 respectively.

Vienna in Austria was crowned the world’s best city for quality of life by the survey for the ninth year running with Mercer citing “high security, well-structured public transport and a variety of cultural and recreation facilities.”