N-Methyl-β-carboline-3-carboxamide (FG 7142), an anxiogenic agent in airborne particles and cigarette smoke-polluted indoor air

β-Carboline-3-carboxylic acid methylamide (FG 7142), an anxiogenic agent, has been measured in airborne particles, automobile-exhaust particles, incinerator ash, smoke condensate of tree leaves and cigarette-smoke-polluted indoor air by high-performance liquid chromatography. This compound has been detected in indoor as well as outdoor air. The source of this compound in indoor air was determined as cigarette smoke, identified from smoking machine studies. This anxiogenic agent was detected in smoke condensate of tree leaves and incinerator ash from garbage burning plants, but not in dieselexhaust particles. Considering the present results, together with the previous finding that cigarette smoke contains this compound, FG 7142 is likely to be formed through combustion of plants. Our data also suggest that this compound may be widely distributed in the environment.