Analysis of Factors Affecting the Formation of Major Mutagenic Substances in Diesel Particulate Extracts

Recently, mutagenicity of polynuclear aromatic hydrocarbons in particulate extracts of Diesel engine exhaust has been attracting attention. The effects of fuel injection system design and properties of fuel on the amount of two major mutagenic substances, i.e. 1-nitropyrene and benzo(a)pyren were analyzed in this study using a 4 cylinder IDI Diesel engine, Formation of 1-nitropyrene and benzo(a)pyren on the filter was also investigated.

As the result, secondary injection from the fuel injection nozzle was found to be a principal factor in increasing these substances. Modification of the fuel injection system to suppress secondary injection can reduce these mutagenic substances.