Cross-Sectional Study of Secondhand Smoke Exposure and Associated Perceived Risks Among Non-Smoking Adults in Motor Parks in Lagos, Nigeria

Secondhand smoke (SHS) exposure remains a critical global health threat, causing an estimated 1.3 million deaths annually and classified by the World Health Organization (WHO) as a Group 1 carcinogen with no safe level of exposure. In Nigeria, SHS contributes substantially to both communicable and non-communicable diseases despite the National Tobacco Control Act (NTCA) of 2015, which incorporates key provisions of the WHO Framework Convention on Tobacco Control (FCTC); however, enforcement gaps and limited public awareness continue to undermine its effectiveness. This study assessed the prevalence of SHS exposure and examined associations between socio-demographic characteristics, knowledge of tobacco legislation, and perceived risks of SHS among 399 non-smoking adults recruited through systematic sampling in Ajah and Obalende motor parks in Eti-Osa LGA, Lagos State. Using a modified Global Adult Tobacco Survey (GATS) questionnaire, data were analyzed with IBM SPSS version 21, employing descriptive statistics, Chi-square tests, and multivariate logistic regression at a significance level of p ≤ 0.05. The prevalence of SHS exposure was 54.6%, notably higher among middle-aged men, individuals with lower educational attainment, and frequent users of motor parks. Although 69.8% of respondents demonstrated good perceived risk of SHS - reflecting awareness of its respiratory, cardiovascular, and carcinogenic harms - knowledge of the NTCA was poor (44.2%), indicating that understanding of health risks has not translated into awareness of legal protections or compliance with smoke-free regulations. These findings underscore the high burden of SHS exposure in outdoor transport settings, exceeding previously reported indoor rates, and highlight the urgent need for strengthened enforcement of smoke-free laws, improved public education on tobacco legislation, and targeted interventions within motor parks to reduce SHS exposure and protect public health.