Impact of secondhand smoke on air quality in partially enclosed outdoor hospitality venues: a review

Abstract

Background Smoking is a leading cause of premature mortality and morbidity globally. The pollutants generated from smoke are not only harmful to smokers, but also to those exposed to secondhand smoke. As a result of increasingly restrictive indoor smoke-free policies in many countries, there is a tendency for tobacco smoking to move outdoors into partially enclosed settings in hospitality venues. The aim of this systematic review was to evaluate the impact of secondhand smoke on air quality in outdoor hospitality venues. Methods Two electronic databases PubMed and Scopus were searched from 1 January 2010 to 30 June 2022 for studies of air quality impacts from tobacco smoking in outdoor hospitality venues. A total of 625 studies were screened and 13 studies were included in this review. Results The majority (9 studies) of reviewed studies monitored PM2.5 concentration as an indicator of secondhand smoke. PM2.5 was reported from 10.9 µg/m3 to 91.0 µg/m3 in outdoor smoking areas, compared to 4.0 µg/m3 to 20.4 µg/m3 in outdoor control sites unaffected by smoking. Secondhand smoke can also drift into adjacent outdoor areas or infiltrate into indoor environments thus affecting air quality in spaces where smoking is not permitted. Conclusions The reviewed studies indicated that air quality within outdoor hospitality venues where smoking is permitted is unlikely to meet current World Health Organization (WHO) ambient air quality guidelines for PM2.5. Customers and staff in outdoor hospitality venues with active smoking, and in adjacent outdoor and indoor non-smoking areas, are potentially exposed to secondhand smoke at levels exceeding WHO guidelines. Stronger smoking control policies are recommended for outdoor hospitality venues to protect the health of customers and staff from harmful secondhand smoke exposure. Prospero registration CRD42022342417.