Genotoxic effects in occupational exposure to formaldehyde: A study in anatomy and pathology laboratories and formaldehyde-resins production

Abstract

BackgroundAccording to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Presently, the International Agency for Research on Cancer classifies formaldehyde as carcinogenic to humans (Group 1), based on sufficient evidence in humans and in experimental animals. Manyfold in vitro studies clearly indicated that formaldehyde can induce genotoxic effects in proliferating cultured mammalian cells. Furthermore, some in vivo studies have found changes in epithelial cells and in peripheral blood lymphocytes related to formaldehyde exposure.MethodsA study was carried out in Portugal, using 80 workers occupationally exposed to formaldehyde vapours: 30 workers from formaldehyde and formaldehyde-based resins production factory and 50 from 10 pathology and anatomy laboratories. A control group of 85 non-exposed subjects was considered. Exposure assessment was performed by applying simultaneously two techniques of air monitoring: NIOSH Method 2541 and Photo Ionization Detection equipment with simultaneously video recording. Evaluation of genotoxic effects was performed by application of micronucleus test in exfoliated epithelial cells from buccal mucosa and peripheral blood lymphocytes.ResultsTime-weighted average concentrations not exceeded the reference value (0.75 ppm) in the two occupational settings studied. Ceiling concentrations, on the other hand, were higher than reference value (0.3 ppm) in both. The frequency of micronucleus in peripheral blood lymphocytes and in epithelial cells was significantly higher in both exposed groups than in the control group (p < 0.001). Moreover, the frequency of micronucleus in peripheral blood lymphocytes was significantly higher in the laboratories group than in the factory workers (p < 0.05). A moderate positive correlation was found between duration of occupational exposure to formaldehyde (years of exposure) and micronucleus frequency in peripheral blood lymphocytes (r = 0.401; p < 0.001) and in epithelial cells (r = 0.209; p < 0.01).ConclusionsThe population studied is exposed to high peak concentrations of formaldehyde with a long-term exposure. These two aspects, cumulatively, can be the cause of the observed genotoxic endpoint effects. The association of these cytogenetic effects with formaldehyde exposure gives important information to risk assessment process and may also be used to assess health risks for exposed workers.

Micronucleus assay in formalin exposed individuals

“…10 Shekawat, in his study proved the same as a significant increase in the MN frequency was found between duration of exposure to formaldehyde (year of exposure) and frequency of micronuclei in the epithelial cells (<0.05). 12 It was well correlated with the results of our study which showed increased MN Frequency in the individuals who had more than 10 years of formalin exposure Sasane et al, in their study, both in peripheral blood lymphocytes (p < 0.001) and in epithelial buccal cells (p < 0.001) the MN frequency was high in occupationally exposed workers than in the control group 11 concluded that inhalation through oral and nasal cavity damage the oral and nasal mucosa respectively. This showed that, exposure duration also had some relevance with the development of health issues.…”

Influence of Serum Levels of Vitamins A, D, and E as well as Vitamin D Receptor Polymorphisms on Micronucleus Frequencies and Other Biomarkers of Genotoxicity in Workers Exposed to Formaldehyde

“…The results presented here are part of a broader human biomonitoring study on how occupational exposure to formaldehyde (FA) influences the frequency of genotoxicity biomarkers as reported in Viegas et al [16] and Ladeira et al [17]. The latter study was reevaluated confirming the statistically significant differences between exposed and nonexposed groups [18], and a significant association between XRCC3 Thr241Met polymorphisms was found [19].…”

“…Exposure data had already been published in Viegas et al [16]; in short, it should be noted that the mean level of FA exposure was below the Occupational Safety and Health Administration (OSHA) reference of 0.75 ppm. However, the mean of the peak concentrations found in the laboratories was 1.14 ppm, which was above the 0.3 ppm reference of the American Conference of Governmental Industrial Hygienists (ACGIH) for ceiling concentrations.…”

“…Exposure assessment was based on two techniques of air monitoring, measuring time-weighted average according to the National Institute of Occupational Safety and Health Method - NIOSH 2541 [20] and ceiling values of FA using photoionization detection equipment (11.7 eV lamps) with simultaneous video recording [21], conducted simultaneously as described previously by Viegas et al [16]. …”

Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?

“…In its natural state, formaldehyde is a gas, and due to its high water solubility, aqueous solutions of the reactant can be produced (1). It is a compound with a wide range of industrial applications and is commonly used in anatomy and pathology laboratories as a fixative to preserve anatomical specimens.…”