Abstract
Dear Editor,
Formaldehyde is a known carcinogen (Nielsen & Wolkoff, 2010). However, formaldehyde is still widely used in health care. According to the Occupational Safety and Health Administration (OSHA), formaldehyde is a contaminant exposure that should be assessed in health care settings (Knight, Sleeth, Larson, & Pahler, 2013). In medical education, students are still required to complete a course in human anatomy and part of the course is scheduled in anatomy laboratories. Of interest, formaldehyde is the most common chemical substance used to preserve donated cadavers for study. The cancer risk due to exposure to formaldehyde in anatomy laboratories is difficult to quantify. In the Knight et al. study, the authors estimated the risk for cancer due to exposure to formaldehyde in the anatomy laboratory at a medical university in Thailand. This anatomy laboratory is one of the largest in Thailand, and the cadavers are provided by a donation center of the Thai Red Cross Society.
The predicted cancer incidence due to exposure to air formaldehyde in this anatomy laboratory was calculated. The individual lifetime cancer risk was estimated by standard calculation according to the formula “individual lifetime cancer risk = concentration of air formaldehyde in anatomy laboratory × lifetime unit risk factor.” The unit risk factor for formaldehyde is equal to 1.3 × 10−5 m3/µg (http://www.daq.state.nc.us/toxics/risk/), and the reported concentration of air formaldehyde in this setting was between 71.42 and 143.72 ppb or 85.70 and 172.46 µg/kg (formaldehyde 1 ppb = 1.2 µg/kg; density of formaldehyde = 8.153 × 10−4 kg/m3; Kajornchaikoon, 1999). Hence, the calculated individual lifetime cancer risk is between 9.08 × 10−7 and 1.82 × 10−6. This level is considerably low indicating the low risk of cancer among medical students enrolled in gross anatomy. Indeed, Vasudeva and Anand (1996) previously assessed chromosomal aberrations in peripheral blood lymphocytes of medical students after completing gross anatomy. According to that study, short term exposure to low-level formaldehyde (1 ppm) causes no cytogenetic aberration (Vasudeva & Anand, 1996). In fact, Ahmed (2011) recently reported that the formaldehyde level in the anatomy laboratory was usually higher than other laboratories but still within acceptable levels. Nevertheless, although the risk for cancer is low, the problem of acute exposure such as skin and pulmonary irritation should not be overlooked. It is of some interest that anatomists are occupationally exposed to formaldehyde, and the estimation of lifetime risk is more complex. Personal protective equipment should be provided and air formaldehyde controls should be implemented to increase the safety of medical students, faculty, and staff. Also, the authors propose further research in hospital pathology laboratories and autopsy rooms.