Formaldehyde concentration in the air and in cadavers at the gross anatomy laboratory in Hiroshima University

The formaldehyde concentration in the air and in various tissues of 35 human cadavers were measured during a gross anatomy course held at the Faculty of Medicine of Hiroshima University in the 2003 educational year. Atmospheric formaldehyde levels were 0.25-0.55 ppm and thus less than the upper limit of the guideline for formaldehyde exposure (0.5 ppm) set by the Japan Society for Occupational Health (1988) except for one out of 10 measurements. The formaldehyde concentrations in tissues were as follows: the lung, 0.12 +/- 0.09% (n=29); the liver, 0.12 +/- 0.09% (n=29); and the brachioradialis muscle, 0.11 +/- 0.09% (n=30). Considerable variation was found among the cadavers and these values were lower than those of Tsurumi University which provided the only other data (average formaldehyde concentrations ranged from 0.27 to 0.32%). At Hiroshima University, blood is allowed to drain during embalming, whereas it is not at Tsurumi University. Differences in the embalming procedure are thus responsible for low and fluctuating formaldehyde concentrations in cadavers at Hiroshima University, and it is conceivable that relatively low formaldehyde levels in the air result from low formaldehyde concentrations in cadavers and good room ventilation (10 room-air changes per hour). However, the Japanese Ministry of Health and Welfare recommended lower formaldehyde exposure levels (0.08 or 0.25 ppm) in 2002. Thus, it may be necessary to further reduce formaldehyde levels in the gross anatomy laboratory by means of such measures as neutralizing formaldehyde with ammonium carbonate; using a locally ventilated dissection work-table, etc.