Objective This paper considers the evidence on whether outdoor secondhand smoke (SHS) is present in hospitality venues at high levels enough to potentially pose health risks, particularly among employees.

Data sources Searches in PubMed and Web of Science included combinations of environmental tobacco smoke, secondhand smoke, or passive smoke AND outdoor, yielding 217 and 5,199 results, respectively through June, 2012.

Study selection Sixteen studies were selected that reported measuring any outdoor SHS exposures (particulate matter (PM) or other SHS indicators).

Data extraction The SHS measurement methods were assessed for inclusion of extraneous variables that may affect levels or the corroboration of measurements with known standards.

Data synthesis The magnitude of SHS exposure (PM_2.5) depends on the number of smokers present, measurement proximity, outdoor enclosures, and wind. Annual excess PM_2.5 exposure of full-time waitstaff at outdoor smoking environments could average 4.0 to 12.2 μg/m³ under variable smoking conditions.

Conclusions Although highly transitory, outdoor SHS exposures could occasionally exceed annual ambient air quality exposure guidelines. Personal monitoring studies of waitstaff are warranted to corroborate these modeled estimates.