"RISK ASSESSMENTS OF FORMALDEHYDE AND ACETALDEHYDE IN AMBIENT AIR TO THE GENERAL POPULATION IN JAPAN"

Masato Naya, Junko Nakanishi, Kikuo Yoshida

National Institute of Advanced Industrial Science and Technology

  International Congress of Toxicology (Canada Montreal 2007/7/16)

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Abstract

Formaldehyde and acetaldehyde are the most abundant aldehydes in ambient air and may be considered as both primary and secondary pollutants. The purpose of this study is to provide an up to date critical review of the information to the toxicological profile of formaldehyde and acetaldehyde, and assess the risk to the general population in Japan. Inhaled formaldehyde is an effectcive sensory irritant at a dosage of 0.5 ppm in mice. Following inhalation in laboratory animals, more than 6 ppm of formaldehyde causes degenerative non-neoplastic effects in mice and monkeys, and nasal tumors in rats. It is considered that formaldehyde induce genotoxic effects directly in vitro, and secondary in vivo. The sensory irritation of eyes and respiratory tract of inhalation exposure to formaldehyde were reported at 0.08 ppm and above in human study. Formaldehyde is carcinogenic at site of contact, as a consequence of epithelial cell regenerative proliferation resulting from cytotoxicity and mutation, based on studies in both animals and humans. Levels of formaldehyde in air detected in rural, suburban and urban areas in Japan were 2.5 to 3.2 ppb from 1998 to 2003. The majority of the population is exposed to airborne concentration of formaldehyde less than those associated with sensory irritation. The reference concentration of formaldehyde in ambient air to the Japanese general population is recommended to be 0.01 ppm. Toxicological studies and epidemiological data of acetaldehyde are less than that of formaldehyde. The reference concentration of acetaldehyde for non cancer effects is recommended to be 0.007 ppm.

Keywords

Formaldehyde, Acetaldehyde, Risk assessment, Toxicology, Human Health