Atmospheric tail-pipe emissions from motorcycles in Tehran, Iran

Abstract

Worsening environmental conditions in large cities of Iran, such as Tehran, are impeding economic development and creating adverse health consequences. As a common means of transportation, the number of different brands of motorcycles has grown rapidly in Tehran over the past few years. In this study the tail-pipe emissions of randomly selected 2- and 4-stroker have been measured and studied. Motorcycles currently being used in Tehran were tested for carbon monoxide (CO), carbon dioxide (CO2), and hydrocarbons (HC) and compared with emission standards already enforced in some Asian countries like China and Taiwan. It was found that the emissions of CO from some common 4-stroke motorcycles were much higher than from 2-stroke ones, while the CO2 emissions were almost equal to HC emissions for the 2-stroke motorcycles, which was approximately 14000 ppm for all brands. Except for one of the brand of the 4-stroke motorcycles, emissions of HC were less than 1000 ppm.