Aim: We examined potential associations of “ever” asthma, and symptoms of wheeze (past 12 months), hay fever, eczema and bronchitis (cough with phlegm) among school children exposed to second-hand-smoke (SHS) in cars, using a modified Irish International Study of Asthma and Allergies in Childhood (ISAAC) protocol.

Methods: 2,809 children aged 13-14 years completed the 2007 ISAAC self-administered questionnaire selected randomly from post-primary schools throughout Ireland. Adjusted odds ratios [AOR] (adjusted for gender, active smoking status of children interviewed and their SHS exposure at home) were estimated for the associations studied, using multivariable logistic regression techniques.

Results: Overall 14.8% (13.9% in boys, 15.4% in girls) of Irish children aged 13-14 years were exposed to SHS in cars. Although there was a tendency towards increased likelihood of both respiratory and allergic symptoms with SHS exposure in cars, wheeze and hay fever symptoms were significantly higher (AOR with 95% CI: 1.35 [1.08-1.70] and 1.30 [1.01-1.67]), respectively, while bronchitis symptoms and asthma were not significant (1.33 [0.92-1.95] and 1.07 [0.81-1.42]), respectively.

Conclusions: Approximately one in seven Irish school children are exposed to SHS in cars and could have adverse respiratory health effects. Further studies are imperative to explore such associations across different population settings.