A new study reveals the nicotine levels to be found in smokers' cars are 'strikingly higher' compared to that of non-smokers', even exceeding the levels to be found in public / private indoor spaces where smoking is permitted.

Testing the air nicotine concentrations in vehicles belonging to smokers, researchers from the Johns Hopkins Bloomberg School of Public Health found them to be strong than the levels measured in public and-or private places by other studies, including up to 50% higher than that of restaurants and bars, where smoking was allowed.

Dr. Patrick Breysse, the senior author of the study says, they are interested in learning about the effects on a non-smoker exposed to second-hand smoke while travelling in a smokers' car, as it is the last environment people are beginning to think of, regarding the risk of exposure to second-hand smoke.

The confined space of a car represents a unique sub-environment for elevated exposures, and though the exposure is for a shorter period of time it is greater, posing a higher risk for children in particular.

The vehicles of 17-smokers and five non-smokers commuting to and from work for over half and hour were studied, after two passive airborne nicotine samplers were placed in their cars. One sampler was placed on the front passenger seat headrest, while the second was placed on the back seat behind the driver, for a 24-hour period, after which all 44-samplers were analysed.

Taking into account the size of the car and ventilation used, the results showed for every cigarette smoked in the car, the airborne nicotine concentration doubled. Rolling down windows half-way when smoking reduced the exposure, but not as low as researchers expected.

Previous research has also shown, passive smoke in a car can be 23-times more toxic than a home environment.

Published in the British Medical Association journal Tobacco Control, the researchers tested nicotine, finding it to be a good marker for the other chemicals that can be found in second-hand smoke.

A pivotal study, many countries have banned smoking in public places, but the legislation does not apply to smoking in cars, though in Canada, Nova Scotia and Ontario are two provinces that prohibit smoking in vehicles with children present.

Smaller lungs and faster breathing rate makes children especially at risk from the effects of second-hand smoke.

Earlier this year, Ash Ireland lobbied politicians to impose a ban on smoking in cars carrying children under-16, with Dr Angie Brown, chairman of Ash Ireland stating: 'Such a ban is in place in several Australian regions, in parts of Canada and the US, in Cyprus and is under consideration in the Netherlands, South Africa and elsewhere.'

'The high air nicotine concentrations measured in motor vehicles in this study support the urgent need for smoke-free education campaigns and legislative measures banning smoking in motor vehicles when passengers, especially children, are present,' the researchers conclude.