LONDON - Public bicycle sharing schemes such as Barcelona's "Bicing" program or London's "Boris Bikes" save lives and reduce greenhouse gas emissions, according to a study on Friday.

 

Bike schemes are becoming increasingly popular in cities around the world, with more than 360 already running, but their main aim is usually to ease congestion rather than boost health.

 

Researchers at the Center for Research in Environmental Epidemiology in Barcelona found in a study, however, that around 9,000 tons of carbon dioxide pollution are averted and some 12 lives saved each year by Barcelona's scheme, which was introduced in March 2007.

 

"Active transport policies such as bike sharing systems promote physical activity among the population and are a good means to improve public health and also reduce expenses in public health services," said David Rojas-Rueda, whose study was published in the British Medical Journal.

 

Rojas-Rueda's team used a mathematical health impact model to integrate data from scientific studies and local travel information.

 

From this they estimated the number of deaths associated with traveling by bike compared with driving for three main factors — physical activity, road traffic incidents, and exposure to air pollution. They also estimated the reduction in carbon dioxide emissions.

 

Looking at the Barcelona "Bicing" scheme, they calculated an annual increase of 0.13 deaths from air pollution and 0.03 deaths from traffic accidents among cyclists compared with car users.

 

But as a result of high levels of physical activity, 12.46 deaths were avoided, making a total of 12.28 deaths avoided among cyclists every year, the researchers said. They also estimated a reduction in carbon emissions of over 9 million kg or 9,000 tons per year, the equivalent to flying 1,800 people to Sydney and back from London.

 

The World Health Organization (WHO) recommends adults should do at least 150 minutes of moderate exercise a week and says this could be done by walking for 30 minutes five times per week, or by cycling to work every day.

 

Barcelona's scheme was launched in March 2007 and by August 2009, more than 182,000 people had subscribed to it — 11 percent of the city's population. The average distance travelled by Bicing on a working day was 3.29 km (2.04 miles), taking an average of 14 minutes, according to the study's findings.

 

The researchers said this initial assessment suggested it was important "to encourage cities to change car use by cycling and stimulate the implementation of bike sharing systems in cities to improve the health of the population."

 

London Mayor Boris Johnson, who a year ago launched the bicycle scheme dubbed "Boris Bikes" by residents of the British capital, says Londoners have made more than 6 million journeys using the cycles since last July.

 

(Editing by Paul Casciato)