Objectives To determine the relationship between exposure to second hand smoke of WP and systemic inflammatory markers, among employees working in cafés and restaurants. Methods: A cross sectional survey was conducted among employees at cafés and restaurants of Karachi, Pakistan where WP smoking facility is offered to consumers. Participants were selected through convenience sampling. Data were collected by using questionnaire, and blood samples were drawn to measure systemic inflammatory markers (Neutrophil to lymphocyte ratio, Air samples were collected to measure CO levels in cafés using Carbon Monoxide USB Data logger. The estimated time for the completion of study was one year. Results: A total of 181 participants were included in the study. Among participants, 48.1% (n=87) were unexposed to SHS, 31.5% (n=57) were exposed to SHS of WP, and 20.4% (n=37) were exposed to SHS of cigarette & WP. Generalized linear regression models were also run and found that exposure to SHS of WP was not statistically significantly associated with NLR (β= -0.01, 95% CI [-0.35-0.32], p-value=0.930) and for those who were exposed to SHS of cigarette & WP (β= -0.09, 95% CI [-0.48-0.29], p-value=0.630) but it was positively associated with Platelet to Lymphocyte Ratio (β= 6.05, 95% CI [5.72-6.38], p-value< 0.001) for those who were exposed to SHS of WP. Conclusion: In this study, we did not find any association between exposure to SHS of WP and systemic inflammation using different markers. However, the cross sectional nature of data and uncontrolled confounding and relatively lower level of exposure in our study sites may explain the overall findings of this study. Keywords: Advocacy, Chronic disease management and prevention, Occupational health Key messages: 1. The studies discussing SHS face the challenge of precise classification of SHS exposures and consequently the evidence on classification of SHS exposure is critical while studying the effects of SHS 2. The assessment of exposure includes factors like time and place of the exposure, cumulative exposures, exposure during a particular time, or a recent exposure 3.It is also difficult to assess the exposures because people go to a number of environments where exposures take place

Rabia Baloch