Particulate and trace metal emission from mosquito coil and cigarette burning in environmental chamber

The objectives of this study were to characterize the emissions of indoor air pollutants from the burning of mosquito coils and cigarettes using a closed environmental chamber, to compare air pollutant emissions from different types of mosquito coils and cigarettes, which are popular in Indian market; to quantify emissions from burning of mosquito coils and cigarettes with respect to particulate matter (PM0.25, PM1.0,PM2.5, and PM10) and metals. Smoke contains several thousands of chemicals and heavy metals, and most of them are formed during the burning of cigarettes and burning of mosquito coils. The present study attempts to characterize the emissions of PM and heavy metals from different types of mosquito coils and cigarettes burning which were monitored in three different phases pre-burning, during burning, and post-burning. Five different brands of cigarette and mosquito coils were taken which are commonly used in India. Samples collected were analyzed for heavy metal (Al, Cu, Zn, Cd, Cr, Mn, Ni, Pb, V, Se, and Sc) concentration using ICP-AES, and the morphological analysis was performed with the help of scanning electron microscopy. The trend of concentration of PM in mosquito coil is followed as M1 > M3 > M2 > M4> M5, and in a cigarette it was C5 >C2 > C4 > C3 > C1. The study suggests that burning of mosquito coil and a cigarette in the indoor environment emits quiet higher respirable PM, which may on prolonged exposure lead to illnesses. The maximum concentration of Al, Cu, Zn and Mn was found higher, while that of Cd, V and Se was below the detection limit in both types of samples. Calculations were made to explore expected cancer and non-cancer risks, using published toxicity potentials for three metals (Cr, Pb, and Ni). Hazards quotient values for adults were under safe limit. The order of excess cancer risk for the carcinogenic elements follows the similar trend for both cigarette and mosquito coils in adults; it was observed as Pb < Ni<Cr. Overall, the cancer risk was below the acceptable level (10(-4) -10(-6) ).