Background:
Second hand smoke (SHS) is a danger to human health with no safe levels of exposure. With the recently enacted state-wide anti-smoking law, this study aimed to examine the self-reported exposure to SHS and assess the support for smoke-free policies among residents of Oriade Local Council Development Area, an urban district in Lagos.

Methods:
This cross sectional descriptive study was carried out among 355 respondents in July 2016, two years after the enactment of the state-wide anti-smoking law. Multistage sampling method was used to select the respondents. Data was collected using interviewer-administered questionnaires adapted from the Global Adult Tobacco Survey (GATS) and analysed using EPI-INFO 7 statistical software.

Results:
The mean age of the respondents was 33.9 ± 11.0 years. Majority of the respondents (62.0%) had good knowledge of the effects of SHS but 89.0% were unaware of the Lagos state anti-smoking law. Attitudes towards SHS were generally positive as 94.9% of respondents had little tolerance for SHS. Most (83.2%) disallow smoking in their homes and over ninety percent agree adults should not smoke around children. About two-thirds support a law that prohibits smoking in all public places, over half (55.5%) support a law prohibiting advertisements for tobacco products, and (73.3%) agree that there should be a total ban on the production of tobacco products. Majority of the respondents reported exposure to second hand smoke at work (47.3%), restaurants (54.7%), markets (59.4%), bars and clubs (58.6%), roadside (86.8%), bus stops (84.2%) and motor parks (85.6%). About seventy percent were non-smokers.

Conclusions:
Knowledge and attitude to second-hand smoke was good, while knowledge of the anti-smoking law was poor. Exposure to SHS was high which calls for enforcement of the anti-smoking law, awareness and education campaigns on the effects of SHS in Lagos.