Formaldehyde Concentration of Ambient Air at Kasumigaseki in Tokyo

Abstract

Since January 1968, the continuous analyzer of formaldehyde, developed by the authors, has been operated at the National Autoexhaust Monitoring Kasumigaseki Station in Tokyo. This report presents summarized results of the measurement of formaldehyde from 1968 to 1976. It was observed that the hourly, daily, monthly, and yearly average concentrates were 1 to 73, 1 to 28.4, 3.1 to 19.1, and 4.6 to 10.5 ppb, respectively. Daily average concentration showed logarithmic normal distribution. Relationship between the daily and hourly average concentrations (daily maximum) was about 1 to 2. Daily maximum value was observed at ca. noonday and yearly maximum was found during June and August. © 1979, The Chemical Society of Japan. All rights reserved.