Financial Tribune- Tehran has been ranked as the sixth most stressful city among 150 cities studied in relation to traffic levels, public transport, green spaces, financial status of residents including debt levels, physical and mental health, and the hours of sunlight the city gets per year.

The study by UK-based Zipjet Company was conducted by studying 500 locations based on data relating to 17 categories covering infrastructure, pollution levels, finance and people�s wellbeing. This determined the ranking of 150 cities with available data on all factors relating to the study.

A low score indicates a low level of stress, with each increasing number indicating a higher level of stress for the factor. A score of 1 represents the least amount of stress possible and 10 indicates the most.

Of the 150 cities ranked, four out of the top ten most stress-free cities are in Germany. The southern city of Stuttgart comes out on top, with Hanover in third place, Munich is fifth and Hamburg in joint ninth place with Graz, Austria.

The tiny yet wealthy country of Luxembourg, home to fewer than 600,000 people, has the second-lowest stress levels. Bern, Switzerland is fourth, while Bordeaux, France (No. 6) and Edinburgh, UK (No. 7) also make it to the top of the charts.

The city ranked the most stressful overall is Baghdad, Iraq -- with a total score of 10 compared with Stuttgart�s one -- followed by Kabul, Afghanistan.

Tehran is the only Iranian city mentioned in the list and is ranked 145 among the 150 cities listed with the total score of 9.1.

According to Zipjet website, anxiety and stress have been pinpointed as key factors contributing to the deterioration of mental health and quality of life, so it conducted this study to find out how the most stressful cities around the world can benefit from the example of those cities least affected by stress.

�Mental health problems are on the rise worldwide, with stress being a trigger and contributing factor towards this increase. We hope that by pinpointing how the least stressful cities are managing this issue, those cities struggling with a stressed out population can overcome it,� says the managing director of Zipjet, Florian Farber.

In the factors assessed by the Zipjet, Tehran has received a score of 8.67 in population density (population per square kilometer), 9.21 in green spaces (percentage of public green spaces inside the city limits), 6.62 in satisfaction with public transport, 8.55 in traffic congestion levels, 9.4 in perception of security (weighted average rate of theft and murders ), 3.66 in average percentage of sunshine hours per year, 8.25 in annual mean air pollution, 4.5 in noise pollution, 6.98 in light pollution, 8.55 in unemployment rate, 7.52 in debt per capita, 1.30 in social security, 7.77 in family purchasing power, 6.07 in mental health, 7.95 in physical health, 9.76 in gender equality, and 9.1 in race equality.