Investigation of the impact of the smoke-free legislation in Northern Ireland on second hand smoke exposure of adult non-smokers living with smokers:

On 30th April 2007 legislation was introduced in Northern Ireland to prevent smoking in enclosed public places and workplaces. A baseline study was carried out in five geographical areas in Northern Ireland before the introduction of the legislation on second hand smoke exposure for adult non-smokers who live with at least one smoker. A follow-up survey was carried out 12 months after the baseline study. Information on exposure to second hand smoke at home and elsewhere, as well as information on attitudes towards smoking and the legislation and some minor health outcomes were collected through a telephone interview. In total, 604 participants took part in the baseline study, 496 (82%) of whom agreed to be contacted again for the follow-up study. These participants were first approached by letter to inform them that they would be contacted again. We subsequently aimed to complete the questionnaire by telephone interviews. Of the 496 participants in the baseline study, 255 participants took part in the follow-up survey, or 52% of eligible baseline study participants. Limited statistical analyses of the data were carried out. The phase 1 sub-population that participated in both phases was significantly older and consisted of significantly more females than the sub-population that only participated in the first survey. However, no significant differences in highest education level or employment status were observed between these two sub-populations. The results on attitudes towards the smoking and perceived health risks from inhaling second hand smoke appeared to be very similar to the baseline results. The self-reported duration of SHS exposure in the home during a day was reduced by more than 40%; similarly, the total self-reported duration of SHS over a day was reduced by more than 50% The results on attitudes towards the smoking and perceived health risks from inhaling second hand smoke were nearly identical for the two surveys. In contrast the results of the nicotine measurements indicate that residential airborne nicotine levels have remained the same or possibly even increased in phase 2 compared with phase 1 (van Tongeren et al., 2008b). Further research into residential exposure to SHS exposure are required to determine long-term trends in exposure.