The figures, published today, show 58 of 152 NSW councils had banned smoking in areas such as playgrounds, swimming pools and alfresco-dining areas by May, up from 28 councils in 2007.

The implementation of smoke-free outdoor areas has been higher in metropolitan municipalities, with 65 per cent of 43 councils introducing the bans, compared with 28 per cent of 109 regional councils.

Warringah, Wollongong City, Camden, Hurstville and Port Stephens are the latest councils to approve a smoke-free policy in council-owned outdoor areas.

The Heart Foundation says there is emerging evidence that secondhand smoke in outdoor areas where people tend to congregate, including alfresco-dining areas, sports stadiums and concert venues, can present a health risk to the public and staff.

A recent study of cigarette smoke levels in a variety of outdoor locations showed that a person sitting near a smoker in an outdoor area could be exposed to levels of cigarette smoke similar to those experienced by someone sitting in an indoor pub or club.

There is also evidence to suggest that smoke-free areas support smokers who are trying to quit as well as reduce their overall cigarette consumption.

The chief executive of the Heart Foundation, Tony Thirlwell, said there had been some resistance to the idea in some councils, but complacency was the largest factor in more NSW councils failing to follow suit.

"In the councils which have implemented the policy, there's largely been a particular councillor that's felt strongly about the issue and been an advocate for it," he said.

Of the 58 councils with smoke-free policies, 95 per cent cover playgrounds, making this the most common smoke-free area. Sporting fields (78 per cent), pools (26 per cent), beaches (17 per cent) and alfresco-dining areas (16 per cent) were included to various degrees.

"While there are fines for breaching the policy, we're not into policing, such as getting council rangers to hunt out smokers," Mr Thirlwell said.

"But we do hope it raises awareness in the community, so that people walk away from others if they want to smoke."