Neurotoxicity Assessment of Secondary Organic Aerosols by Intranasal and Inhalation Exposure in Mice

Abstract

Ambient particulate matter (PM) consists of primary particles emitted directly from the source, and secondary particles formed by photo-oxidation reactions of volatile organic compounds and gases in the atmosphere, which are known as secondary organic aerosols (SOAs). Diesel exhaust (DE) is a major source of PM and a possible precursor of SOAs in the urban atmosphere. In our research institute, we generated SOAs by adding ozone to diesel exhaust, and have established a SOA inhalation exposure technique. Using the inhalation facility, we carried out an assessment of the toxicological effects of SOA exposure on the higher brain functions in mice. In this feature article, we shall discuss the results of our evaluation, through various animal studies, of the neurotoxicity observed after inhalation exposure to SOA.