## 3 Results  
The organic compounds identified in the different types of incense sticks after total combustion in the test room are reported in Table 3.  
From Table 3, it emerged that benzene was emitted by all the tested incense sticks, at concentrations ranging between 11.1 and 66.5 ug m\({}^{-3}\). Toluene was emitted from complete combustion in 6 out of 10 incense sticks, at concentrations between 2.7 and 12.6 ug m\({}^{-3}\). 1,3,5-trimethylbenzene was emitted by only two incense sticks, while ethylbenzene, xylenes, and 1,2,4-trimethylbenzene were from only one incense stick. From the total combustion of incense stick #1, 19.8, 3.4, 7.3, and 6.1 ug m\({}^{-3}\) of benzene, toluene, 1,3,5-trimethylbenzene, and 1,2,4-trimethylbenzene were emitted, respectively. Inense stick #2 emitted only benzene (12.1 ug m\({}^{-3}\)), as did incense sticks #3 (22.8 ug m\({}^{-3}\)), #4 (20.6 ug m\({}^{-3}\)), and #5 (16.9 ug m\({}^{-3}\)). Inense sticks showed an emission of benzene, toluene, and 1,3,5-trimethylbenzene at concentrations of 11.1, 2.7, and 5.8 ug m\({}^{-3}\), respectively. Inense sticks #7, #9, and #10 emitted benzene and toluene during total combustion at concentrations of 66.5 and 12.6 ug m\({}^{-3}\), 38.6 and 6.8 ug m\({}^{-3}\), and 54.2 and 6.2 ug m\({}^{-3}\), respectively. Finally, incense stick #8 emitted benzene, toluene, ethylbenzene, and xylenes at concentrations of 62.5, 12.6, 3.0, and 3.5 ug m\({}^{-3}\), respectively. The background levels resulting from the analyses showed an average benzene background level of 5 ug m\({}^{-3}\). The other studied VOCs were under the LODs values. The results of the blanks are reported in Table 4. The benzene and toluene values determined in the chamber experiment were experimentally subtracted from the blank values. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Inense** & **\# Sticks/L** & **Benzene** & **Toluene** & **Ethylbenzene** & **Xylenes \({}^{\star}\)** & **1,3,5-** & **1,2,4-** \\  & & & & & & **Trimethylbenzene** & **Trimethylbenzene** \\ \hline \#1 & 2/58 & 19.8 & 3.4 & \textless{LOD} & \textless{LOD} & 7.3 & 6.1 \\ \#2 & 2/57 & 12.1 & \textless{LOD} & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \#3 & 2/65 & 22.8 & \textless{LOD} & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \#4 & 2/56 & 20.6 & \textless{LOD} & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \#5 & 2/63 & 16.9 & \textless{LOD} & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \#6 & 2/66 & 11.1 & 2.7 & \textless{LOD} & \textless{LOD} & 5.8 & \textless{LOD} \\ \#7 & 2/63 & 66.5 & 12.6 & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \#8 & 2/64 & 62.5 & 12.6 & 3.0 & 3.5 & \textless{LOD} & \textless{LOD} \\ \#9 & 2/66 & 38.6 & 6.8 & \textless{LOD} & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \#10 & 2/58 & 54.2 & 6.2 & \textless{LOD} & \textless{LOD} & \textless{LOD} & \textless{LOD} \\ \hline \hline \end{tabular}  
\({}^{1}\) benzene 0.1 ug m\({}^{-3}\); toluene 0.18 ug m\({}^{-3}\); ethylbenzene 0.1 ug m\({}^{-3}\); xylenes 0.2 ug m\({}^{-3}\); 1,3,5-trimethylbenzene 0.35 ug m\({}^{-3}\); 1,2,4-trimethylbenzene 0.46 ug m\({}^{-3}\).  
\end{table} 
Table 3: Detected concentrations of each VOC (ug m\({}^{-3}\)) in the air and collected in the test room during the total combustion of the investigated incense sticks. \({}^{\star}\) The term “xylenes” means the mixture of three isomeric compounds of benzene (i.e., ortho-xylene, meta-xylene, and para-xylene). “\(<\)LOD” indicates that the VOC concentrations were below the limits of detection \({}^{1}\): (LODs) values. For the incense stick type: see the text. As evidenced by Table 3, the incense stick that exhibited the greatest quantity of benzene emission was #7, with #8, #10, and #9 following in descending order. Additionally, #7, #8, #9, and #10 were the incense sticks that yielded the highest levels of toluene. Furthermore, Table 4 expresses the levels as absolute ug of toxic and/or harmful substances sampled directly from the combustion of each stick after total combustion.