DIESEL EXHAUST EMISSIONS: METHODS OF MEASUREMENT REGARDING HEALTH EFFECTS: A REVIEW

The aim of this review is to discuss the measurement and evaluation of diesel exhaust emissions and imissions, especially indicators for diesel exhaust, i.e. characteristic components of the exhaust, that are used in certification regulations or in setting standards for air quality or defined for more or less casual use in research and development. The review with 215 references of the scientific and technical literature is presented on emissions and imissions from diesel engines, their generation, biological effects and determination in certification tests and environmental monitoring. Although the diesel engine have many advantages, e.g. the high energy efficiency and the versatility regarding fuels, there are also disadvantages, especially the relatively high rate of emission of particles. Particles tend to soil the environment, but above all they contain harmful substances and indications accumulate that fine or ultra fine particles irrespective of their composition, irritates the lung tissues, causing a number of deleterious effects on the lungs and air-ways and may even cause cancer. Multi-disciplinay research is warranted to investigate a number of questions that are raised. Hitherto vehicle certification regulations concern all particles that can be collected from diluted exhaust from a temperature of +52 EC or less and therefore do not discriminate between particles of different kinds, that may and may not be harmful to the health of people. It is suggested that the further development of engine design, fuel and after-treatment of exhaust should consider the health effects of particles. Based on present knowledge a preliminary sampling and analysis recommendation for diesel engine emission measurements has been outlined in this review. Moreover research and development should address methods to determine particles originating from diesel engines and criteria for certification of engines, fuels and after-treatment of exhaust vehicles and the development of criteria for health standards of immissions in the environment and in work-environements. (A)