One in eight teenagers in Dublin are exposed to second-hand smoke in cars, even though it is illegal, according to a study.
The research examined second-hand smoke in seven EU cities - Dublin; Tampere, Finland; Amersfoort, Netherlands; Hanover, Germany; Coimbra, Portugal; Namur, Belgium; and Latina, Italy.
Minors who are frequently exposed to second-hand smoke in vehicles have been found to be more likely to be diagnosed with asthma, persistent wheezing and decreased lung function.
The study showed passengers in a car are exposed to airborne toxins comparable to or higher than those in smoky bars.
The study found Dublin has the second-lowest level of exposure of the seven cities at 12pc.
Smoking in cars with children has been banned here since the start of 2016.
Tampere had the lowest rate at 6pc, while weekly second-hand smoke in cars was highest in Latina at 43pc and 36pc in Namur.
"In most of these seven cities, a considerable proportion of youths riding in cars, particularly those from disadvantaged and smoking-permissive backgrounds, are exposed to second-hand smoke in cars," the study said.
The research also found a migration background, with both parents having been born in another country, was linked to higher odds of being exposed than having parents without a migration background.
Low paternal and maternal educational levels was also associated with second-hand smoke exposure in cars in the study, which has just been published in Drug and Alcohol Dependence.
The research, headed by Dr Martin Mlinaric from Martin Luther University Halle-Wittenberg in Germany, was based on self-reported survey data on second-hand smoke exposure in cars during the past seven days from more than 10,000 adolescents aged 14 to 17.
The authors noted that cars were found to be a major source of harmful second-hand smoke exposure among youths in Canada and the US, but less is known about the magnitude of this public health problem in Europe.
They found the smoke exposure mostly takes place for one or two days in the week and said smoking bans in cars with children have usually decreased the exposure by at least 40pc.