Effect of Formaldehyde Exposure on Oxidative Stress Markers, Liver and Kidneys of Medical Students during Dissection in Gross Anatomy Laboratory

Abstract

Background: Medical students are routinely exposed to formaldehyde during their dissecting practical classes and human exposure to formaldehyde is associated with multiple adverse effects. Chronic exposures may cause oxidative stress and may result in some vital organ damage.

Materials/Methods: The study included the total class population of the 2017 set of medical students (56 male students) from College of Medicine, Chukwuemeka Odumegwu Ojukwu University, Uli. These students were recruited immediately after first year, that is, before the commencement of dissection. Baseline samples were collected before exposure to formaldehyde. Subsequent samples were collected at one month, three and six-month intervals. All samples were collected immediately after dissection at the required period. The dissection periods are two times per week each lasting for 3 hours (1-4 pm). Eight millilitres (8 ml) of fasting blood samples were collected from all subjects by sterile disposable syringes into a sterile plain container and allowed to clot, retracted and centrifuge at 3000 rpm for 10 minutes. Thereafter, serum was separated into two aliquots. One part of the samples were stored at -20 ˚C for analysis of oxidative stress markers (GPx, SOD and MDA) within two weeks of collection, while the remaining aliquot was stored at -20 ˚C and used for the analysis of liver and kidney markers. Data obtained was analyzed using SPSS version 2021.

Results: Glutathione peroxidase and superoxide dismutase (SOD) activities were significantly reduced after one and three-month periodic exposures when compared with the baseline study. Malondialdehyde (MDA) level was significantly lower when the baseline study was compared with the one month and three-month exposure but does not differ significantly from that of six-month exposures. The activity of ALT was significantly higher after one and three-month periodic exposures when compared with the baseline study. However, when the baseline study was compared with six-month exposures, it was not significant. When the activities of AST, ALP and other liver markers which include albumin, AFP, total protein, conjugated and unconjugated bilirubin of baseline study were compared with the one, three and six-month periodic exposures, it was not statistically significant across all groups. When the concentrations of the serum electrolytes of the baseline study were compared with one, three and six-month periodic exposures, it was not statistically significant. However, the concentration of urea was found to be significant when one-month periodic exposures were compared with the baseline study.

Conclusion: Formaldehyde exposures during medical training may not cause significant damage to tissues. Apart from the irritation of the eyes, upper airways and skin, there is no clear evidence that formaldehyde induces cellular damage in the vital organs of the students within the short period of exposures