LONDON (Bloomberg) - Instability and fears over terrorism have made life more challenging in many of the world's leading cities over the past year, according to analysis by the Economist Intelligence Unit.

Conditions in 29 major cities have deteriorated, the EIU said in its Global Liveability Index published Thursday (Aug 18), with Western European and US rankings hit by terrorist attacks and social tensions. Thirty factors across health care, safety, education, environment, culture and infrastructure were analysed using data and surveys.

Paris and Athens were two of the fastest-falling cities, though the least tolerable by far of the 140 cities listed remained Damascus, blighted at the epicentre of the civil war in Syria.

"Social unrest" was cited in the decline of several US cities, including Chicago, New York and, lowest of all, Detroit, ranked 57th. The report highlighted regular mass shootings and conflict between black communities and police as key factors.

'Greater Instability' "The latest rankings paint a very bomber picture," the report's editor, Jon Copestake, said in an e-mailed statement. "The global trend for declining livability has become depressingly familiar in recent years as acts of terror in major cities are becoming an increasingly common occurrence. But even discounting terrorism, we are seeing greater instability around the world including unrest in the US, political disruption in Turkey and Thailand and geopolitical disputes in Eastern Europe and Asia."

Teheran's living conditions were among the world's most improved this year. The city jumped four places as a result of the lifting of sanctions on Iran, taking it up to 126th.

Australian and Canadian dominance of the top 10 continued, with Melbourne topping the list for the sixth year in a row. Vancouver was placed 3rd, Toronto 4th, Adelaide and Calgary joint 5th and Perth 7th. With Auckland in 8th place, Vienna, Helsinki and Hamburg were the only non-English-speaking cities to make the top 10. London was unchanged at 53rd.