Background:
Secondhand smoke (SHS) exposure is a global public health concern, to which no safe limits exist. Exposure in outdoor public places poses great health risks. Smoking occurs illicitly in motor parks despite a national tobacco law in place. This study identified the prevalence of SHS exposure among non-smoking adults in Eti-Osa Local Government Area (LGA) and the relationship between knowledge of the tobacco law and perceived risks of SHS exposure.

Methods:
A cross-sectional study of 399 non-smoking adults (18yrs and over) was conducted by systematic sampling. Interviewer administered modified GATS questionnaire was used to obtain responses from drivers, conductors, traders and passengers on socio-demographics, SHS exposure, perceived risk of SHS exposure and knowledge of the national tobacco law. Data was analyzed using SPSS version 21. Bivariate and multivariate analyses were conducted with statistical significance at 95% confidence interval.

Results:
The prevalence of SHS exposure in motor parks was 54.6%, more in middle aged males with low level of education. Frequent use of the motor parks was associated with SHS exposure. The perceived risks of being SHS exposed was good (69.8%) and there was a positive relationship with level of education and health status. There was poor knowledge of the national tobacco law (44.2%) despite good perceived risk of SHS exposure. Following logistic regression, higher level of education was associated with good perceived risks of SHS exposure (OR=0.31; 95% CI = 0.12 - 0.79) and good knowledge was negatively associated with perceived risks (OR = 1.81; 95% CI = 1.17 - 2.79).

Conclusions:
More than half of the participants were exposed to SHS and despite good perceived risks of SHS exposure, knowledge of the national tobacco law was poor. These findings warrant increased public health awareness and calls for policy makers and local authorities to ensure implementation of the law in the public places.