Abstract
In order to examine risk assessment for formaldehyde exposure among medical technicians of a hospital pathological section, we conducted formaldehyde exposure measurements using passive samplers in cooperation with nine medical technicians working at two hospitals. We conducted two types of formaldehyde exposure measurements, long-term exposure measurements (n=30) that deal with the limit of exposure measured as a time-weighted average, and short-term exposure measurements (n=11) specifying the maximum exposure for a short-term event; a ceiling value.
The average of the long-term exposure measurements (n=30) was 0.1 ppm (SD: 0.09 ppm, range: 0.01-0.32 ppm), with two thirds exceeding the Japanese exposure limit (0.1 ppm). The long-term exposure values have a significant positive correlation with duration of exposure to formaldehyde rather than with total work time (Pearson's correlation: 0.791, p=0.000). The rate of overexposure (>0.1ppm) for an exposure duration longer than 60 min (60%, 9/15) was significantly higher (χ2-test, p=0.005) than for exposure duration less than 60 min (6.7%, 1/15). Regarding short-term exposure measurements (n=11), there was no significant positive correlation between the exposure value and exposure duration. However, approximately half exceeded the OEL-C (0.2 ppm) level proposed by the Japan Society for Occupational Health or the TLV-C (0.3 ppm) level proposed by ACGIH. Considering the results of risk assessment for formaldehyde exposure, medical technicians working in hospital pathological sections could avoid exposure to a high concentration of formaldehyde by improving the handling of pathological samples. Tasks that involve exposure to formaldehyde should be performed in draft chamber with a local ventilation system.
