Reduction of indoor formaldehyde concentrations and subjective symptoms in a gross anatomy laboratory

A comparison of engineering controls for formaldehyde exposure during grossing activities in health care anatomic pathology laboratories

This article for the first time reports a large set of monitoring results for formaldehyde exposure during grossing activities in health care anatomic pathology laboratories, and compares the effectiveness of different local exhaust ventilation systems on the exposure. To control the confounding effects from grossing work load, sampling duration, and the sizes of specimens grossed, only 15-min short-term personal exposure samples collected during large tissue specimen grossing were used for the comparison of the effectiveness of these local exhaust systems. While we also collected long-term 8-hr time weighted average samples, these are not treated in this analysis. The systems examined were canopy receiving hoods, slot exhausts, and commercially available pre-manufactured backdraft grossing stations, both recirculating and ducted exhaust types. Out of over 2,000 personal short-term air samples, 307 samples from 163 surveys met the data selection criteria. Over a third of the data were less than the analytical laboratory limits of detection. Using the robust maximum likelihood estimation method for multiple limits of detection, the mean and geometric mean of the dataset for each type of local exhaust system were found to be less than the short-term personal exposure regulatory limit of 2 ppm. Nonparametric Wilcoxon rank-sum pairwise tests of five types of engineering controls showed a statistically significant difference among these controls, with the most effective being the manufactured backdraft grossing stations ducted to the outside, and the least effective being canopy exhaust systems and manufactured filtered recirculating grossing stations. Finally, exposure with each of the major engineering control types was rated by the American Industrial Hygiene Association exposure control rating scheme.

Formaldehyde exposure in gross anatomy laboratory of Suranaree University of Technology: a comparison of area and personal sampling

Cadavers are usually preserved by embalming solution which is composed of formaldehyde (FA), phenol, and glycerol. Therefore, medical students and instructors have a higher risk of exposure to FA inhalation from cadavers during dissection. Therefore, the objective of this study was to evaluate the FA exposure in indoor air and breathing zone of medical students and instructors during dissection classes in order to investigate the relationship between them. The indoor air and personal air samples in breathing zone were collected three times during anatomy dissection classes (in January, August, and October of 2014) with sorbent tubes, which were analyzed by high-performance liquid chromatography (HPLC). The air cleaner machines were determined by weight measurement. Pulmonary function tests and irritation effects were also investigated. The mean of FA concentrations ranged from 0.117 to 0.415 ppm in the indoor air and from 0.126 to 1.176 ppm in the breathing zone of students and instructors. All the personal exposure data obtained exceeded the threshold limit of NIOSH and WHO agencies. The air cleaner machines were not significant difference. The pulmonary function of instructors showed a decrease during attention of classes and statistically significant decreasing in the instructors more than those of the students. Clinical symptoms that were observed in nose and eyes were irritations with general fatigue. We suggested that the modified exhaust ventilation and a locally ventilated dissection work table were considered for reducing FA levels in the gross anatomy dissection room.

Occupational exposure to formaldehyde in an institute of morphology in Brazil: a comparison of area and personal sampling

BACKGROUND, AIMS, AND SCOPE

Formaldehyde (FA) is a harmful chemical, which is classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. Solutions of FA that are used to preserve cadavers in research and education morphological institutes represent a risk to occupational health of professionals and students. During the dissection of cadavers in the anatomy laboratories, FA vapors are emitted, resulting in the exposure of students and their instructors to elevated levels of FA. The World Health Organization recommends an air quality guideline value of 0.1 mg m(-3) for exposure to FA. The limit of occupational exposure adopted by the Brazilian legislation (2.3 mg m(-3)) is markedly higher than those adopted by institutions of other countries around the world. The purpose of this study was to determine the levels of personal exposure and the area concentration of FA in the morphology department of the Federal Fluminense University, Brazil, and investigate and compare the relationship between them.

METHODS

Four rooms distributed in the three floors of the Morphology Department were evaluated: the embalming laboratory, the anatomy laboratories, the corridor of the teachers' rooms, and the entrance hall. Thirty-six samples in total were collected in the second semester of 2010 and first semester of 2011. The air sampling and FA analysis were performed according to the EPA TO-11A Protocol, using a diffusive sampling device for carbonyl compounds. Personal samples were collected from monitors using a sampling device pinned on each person's lapel. The samples were analyzed using rapid resolution liquid chromatography with UV-DAD detection at 360 nm.

RESULTS AND DISCUSSION

The concentrations of FA ranged from 0.20 and 0.18 mg m(-3) in the corridor between the teachers' rooms, 0.03 to 0.37 mg m(-3) in the entrance hall, 0.22 to 2.07 mg m(-3) in the anatomy laboratory, 2.21 to 2.52 mg m(-3), in the embalming room. The levels found in the corridor between the teachers' rooms and in the entrance hall were lower than in other compartments because of their large distances to the sources of FA and better ventilation. The other rooms presented higher levels of FA because of the activities carried there (embalming and dissection procedures). Even in the rooms that showed the lowest levels of FA, the values found were higher than those established by all international guideline limits, except the Brazilian legislation limit, although, the concentration level in the embalming room was even greater than the Brazilian guideline. These concentrations are 100-1,000-fold higher than those reported in an FA outdoor study. The exposure levels of monitors and students ranged from 1.89 to 4.82 mg m(-3), indicating that current practices at the Morphology Department at the university would represent a health risk. The simultaneous monitoring of area concentrations and personal exposure showed that the characteristics of classes and of cadavers' parts, the number of students in the room and even the activities of the monitors influence the FA concentrations.

CONCLUSION

This study revealed that the concentration of FA was low in the ventilated areas of the Morphology Department, and that the personal exposure when the person was close to the cadavers during the dissection procedure was higher than the mean FA concentration. This should be considered in the risk assessment of FA during these activities without effective protection equipment. It is suggested that the Brazilian legislation of exposure to formaldehyde requires an urgent update considering international legislation.