www.ccsenet.org/mas Modern Applied Science Vol. 5, No. 2; April 2011 Published by Canadian Center of Science and Education 37 Viability of Myrtle Trees as Natural Filter for the Gaseous Emissions of Internal Combustion Engines Salam J. Bash Al-Maliky Associate Professor Environmental Engineering/ AlMustansiriya University- IRAQ Faculty and Leader in Residence/ Ohio University-USA Received: December 8, 2010 Accepted: December 27, 2010 doi:10.5539/mas.v5n2p37 Abstract This paper was aimed to test the control role of myrtle tree against the gaseous emissions of stationary internal combustion engines (ICEs). CO and NO 2 gaseous emissions, chlorophyll content index (CCI) and leaf surface area were studied prior and after the expose of myrtle tree the exhaust of 2 KW Gasoline fueled, power generator that was operated four hours per day for a period of 24 consecutive weeks. Myrtle have shown efficient performance in reducing the amounts of these emissions, where records of CO and NO 2 have shown reductions to about 18% and 27% of their initial levels as emitted from the source, respectively. Although it was not encouraging at the first few weeks, the CCI has shown significant development of 38% as compared to its initial value, which was incorporated with about 77% increase in average leaf`s surface area. Statistical analyses have proved good positive correlations between CO and NO 2 removal process from one side and the CCI and leaf surface area from the other. Atmospheric temperature was proved to have high negative correlation coefficient with both CCI and leaf surface area. These results encourage further biological and statistical tests to prove and determine the causal relations between these variables. Author would like to acknowledge the support of the Institute of International Education IIE, Scholars Rescue Fund SRF and Russ College of Engineering, Ohio University. Keywords: Chlorophyll content, Gaseous emission, Leaf surface area, Myrtle 1. Introduction Utilization of stationary internal combustion engines (ICE) has diverse forms ranging from power generation to irrigation, and depending on the application, sizes of ICE range from relatively small; 1 Kilowatt for agricultural irrigation purposes to hundreds Kilowatts for power generation. A variety of fuels can be used for ICE including diesel and gasoline among others. The operation of ICE results in the emission of hydrocarbons, carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM), the concentration of which was attributed to the engine type, operation mode and duration and of course the type of fuel used. Various emission control technologies exist for ICE which can afford substantial reductions in all these four criteria pollutants such as the catalyst control technologies, the adoption of which involved the need for technical facilities and experiences in addition to their operational and maintenance costs. There were considerable scientific evidences of beneficial effects of plants in the interior environment. Researchers have shown that common house plants such as Areca Palm, Australian Sword Fern, Boston fern, Dwarf Date Palm, English Ivy, and others, were powerful natural air cleaners. In laboratory studies, test plants removed as much as 87% of indoor air pollutants within 24 hours (Kobayashi, Kaufman, Griffis, and McConnell, 2007). Plants absorb pollutants through their leaves, roots and the bacteria that live on them and then convert these substances to food. The major health and wellbeing benefits of interior plants include; cleaning pollutants out of the air / absorption of harmful substances, filtration of dust and dirt from the environment, producing oxygen and add humidity to the indoor environment, dampening of sound levels, cooling effect, counteracting the common sick building disease, enhancing the beauty of our homes and offices, and last, but not least, the very presence of plants has been shown to increase positive feelings and reduce feelings of stress, anxiety, anger and sadness. The toleration of outdoor plants for fires was studied by Alessio, De Lillis, Fanelli, Pinelli and Loreto (2004), whom observed that Myrtle leaves exposed to elevated temperatures started to emit mono-terpenes, especially α-pinene that was not associated directly with photosynthesis, as it peaked immediately after treatment and decreased with time, which may also have other important ecological consequences, reducing flammability and slowing down combustion of the burning biomass (Owens, Lin, Taylor, and Whisenant, 1998). Myrtle plant