Baalbaki, R., El Hage, R., Nassar, J., Gerard, J., Saliba, N.B., Zaarour, R., Abboud, M., Wehbeh, F., Khalaf-Kairouz, L., Shihadeh, A.L., Saliba, N.A. 2016. Exposure to atmospheric PMS, PAHS, PCDD/FS and metals near an open air waste burning site in Beirut. Lebanese Science Journal, 17(2): 91-103.Since July 2015, Lebanon has experienced the worst solid waste management crisis in its history. Consequently, open-air waste burning in the vicinity of highly populated areas in Beirut has become a common practice. This study evaluates the effects of open-air dumping and burning on local air quality and public health. The levels of particulate matter (PM10, PM2.5), gaseous and particle-bound polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-dioxins and furans (PCDD/Fs), and particle-bound metals at a residence close to waste burning are reported. Concentrations, determined between October 2 and December 2, 2015, were compared either to previous measurements or to measurements taken away from a nearby burning incident, and after it had rained. Subsequently, the cancer risk due to exposure to these chemicals was assessed. Results showed alarming increases in pollutant concentrations which was translated into an increase in short-term cancer risk from about 1 to 20 people per million on the days when waste was being burned. Findings were shared with the public to warn the community against the dangers of waste mismanagement, and underline the obvious need for solid waste management at the governmental and municipal levels.