Abstract
The atmospheric concentrations of 16 component hydrocarbons were calculated by the Chemical Element Balance (CEB) method adapted the major six source contribution values (best-fit CEB coefficients) of 15 component profiles to those fixed with 16 components (15 components+propylene) . As the results, the large part of the unexplained concentration [(measured) - (CEB calculated) concentration] was due to the high atmospheric concentrations of benzene, toluene and ethylbenzene. An another emission source of these aromatic hydrocarbons than the six those used in this study is indicated to be a wastewater, which is proposed by only a report in USA. The study of wastewater components may be necessary for more detailed CEB calculation of the urban ambient non-methane hydrocarbons in Japan . The relatively large differences were observed between the measured and CEB calculated concentrations of propylene at the general air monitoring stations. While, little difference was observed at the roadsides near to the vehicle emission source. The CEB method in this study may give much information to the atmospheric degradation of high photoreactive hydrocarbon such as propylene.
