Secondhand smoke exposure among nonsmoking adults in two Nigerian cities

Background: Tobacco control policy can only succeed if the burdens of smoking are known. The objective of this study was to determine the prevalence and correlates of secondhand smoke (SHS) exposure among nonsmoking adults in two Nigerian cities.
Materials and Methods: We carried out a cross-sectional study from October 2009 to April 2010 among adult population of two Nigerian cities: Enugu and Ilorin. A semi-structured questionnaire was administered by interviewers to obtain socio-demographic information; and information regarding pattern of SHS exposure, awareness of tobacco control policy and the harmful effects of SHS. SHS exposure was defined as regular exposure to tobacco smoke in the previous 30 days in a nonsmoking adult.
Results: Of the 585 nonsmoking adults that completed the study, 38.8% had regular exposure to SHS; mostly, in public places (24.4%). More men were exposed at public places when compared with women (27.0% vs. 19.5%). The strongest factor associated with exposure to SHS in women was having a smoking spouse [prevalence rate (PR) ratio-7.76; 95% confidence interval (CI), 3.08-9.42]; and in men, it was lack of home smoking restriction (PR ratio-6.35; 95% CI, 4.51-8.93). Among men, SHS exposure at any location was associated with lack of secondary school education, residing in slum apartment (house with many households), living with a smoking family member (non-spouse), lack of home smoking restriction, and alcohol intake. Among women, SHS exposure at any location was associated with having a smoking spouse, residing in slum apartment and lack of home smoking restriction. Seventy-two percent of respondents were aware of the harmful effects of SHS on their health. Lack of awareness of the harmful effects was significantly associated with increasing age (r= +0.45; P = <0.01), lack of secondary school education (r= −0.10; P = 0.04), residing in slum apartment (r =-0.12; P = 0.03) and being a widow/ widower (r= +0.24; P < 0.01). Only 17.4% of the employees reported availability of outdoor smoking area at their workplaces.
Conclusion: Our results show that prevalence of SHS exposure was the highest in public places. These findings underscore the need for enactment of comprehensive smoke-free legislation and implementation of educational strategies to reduce SHS exposure in homes.

Keywords
Environmental tobacco smoke, Nigeria, secondhand smoke, smoking ban, tobacco control