Investigation of Formaldehyde in Gross Anatomy Laboratory: Area-Based and Exposure Levels, Ventilation, Health Risk and Clinical Symptoms

Abstract

Formaldehyde is commonly used in embalming solution in medical fields to preserve tissues. Formaldehyde vapor released from cadavers during dissection practice can adversely affect students and instructors in gross anatomy laboratories. Therefore, this study investigated formaldehyde concentrations in a gross anatomy laboratory of Mahasarakham University, Thailand. Area-based sampling was conducted for three scenarios: (1) a laboratory cleaning period, (2) three periods of teaching classes and (3) a non-teaching class period. Personal samples were also collected for five consecutive working days from two anatomy lab instructors and a non-lab instructor. Measurements were conducted during May to October 2016 using cartridges filled with dinitrophenylhydrazine coated silica gel. Samples were desorbed and analyzed by high performance liquid chromatography. Results showed that the average area-based concentrations during the dissection classes ranged from 9.3 to 17.6 ppb, while the non-teaching class concentration was 5.5 ppb. The concentration increased to 3.1×103 ppb during the laboratory cleaning. The five-day average exposure concentrations were 7.6 ppb and 4.7 ppb for the two lab instructors and 1.1 ppb for the non-lab instructor. The lifetime cancer risk estimates were 5.8×10-6, 2.9×10-6 and 8.1×10-7, respectively. The three most reported clinical symptoms by the gross anatomy students were associated with formaldehyde concentrations above 16 ppb at the significance level of 0.05. These included unpleasant odor, general fatigue or fatigue after awakening and dizziness with response rates of 57.5 %, 38.5 % and 33.1 %, respectively. Improvement of the ventilation and source control measures are essential for reducing formaldehyde emissions in the gross anatomy laboratory.

Indoor Formaldehyde Concentration, Personal Formaldehyde Exposure and Clinical Symptoms during Anatomy Dissection Sessions, University of Medicine 1, Yangon

“…Some individuals were highly sensitive to the FA while others were more resistant and had no reaction to the same level of exposure [ 40 ]. In our study, the most frequent complaint reported by the exposed students was the unpleasant smell (78.8%) ( Figure 9 ), and this occurrence is consistent with some previous studies which also reported this symptom as the most predominant one at 68% [ 21 ], 80% [ 41 ], 77% [ 42 ], 57.5% [ 35 ], 91.2% [ 43 ] and, 70.3% [ 44 ]. This common finding simply reflects that FA exposure is mainly by inhalation during the dissection sessions.…”

“…Since irritation is one of the characteristics of FA [ 12 ], symptoms of eye and upper respiratory tract irritations such as eye itchiness, excessive lacrimation, eye redness, blurred vision and nasal symptoms were frequently observed in our study and other previous studies [ 21 , 35 , 42 , 43 , 45 ].…”

“…In the figure, it can be clearly seen that, during most of the dissection sessions, indoor FA concentrations fluctuated but were still above the guideline values set for occupational exposure. This fluctuation in indoor FA concentrations could be attributable to variations in regions of cadavers being dissected [ 20 ] and time spent on dissection [ 21 , 35 ].…”

“…After analyzing TWA values of the exposed subjects, a positive skewness above 1.5 was observed for both exposed students and exposed instructors due to the fact that some of them showed extremely high personal FA exposures ( Figure 8 ). This wide range may be attributable to the individual variations in the time spent in the dissection rooms [ 35 ] and in the distance between the cadavers and the exposed subjects [ 16 ].…”

Formaldehyde Levels and the Indoor Air Quality of Anatomy Dissection Hall with Different Ventilation Setups

“…Studies have found that fan-based ventilation in dissection halls has resulted in higher levels of formaldehyde (FA) [35]. Other reports have shown that personal exposure to FA can be higher than indoor levels when using air conditioning in anatomy halls [36,37,38].…”