Abstract

The mutagenicity of organic solvent extracts of diesel exhaust extracts was first noted over 60 years ago. Epidemiology and toxicology studies have resulted in classification of diesel exhaust by the International Agency for Research on Cancer (IARC) as a known carcinogen and by United States Environmental Protection Agency (USEPA) as likely to cause cancer; however, there is continued debate and quantitative risk has not been established by USEPA or environmental regulatory bodies in other countries. The major changes in diesel exhaust emissions make New Technology Diesel Exhaust (NTDE) distinct from the historic epidemiologic studies and recent animal bioassays question the relevance of studies of traditional diesel exhaust for risk assessment of NTDE.