Occupational formaldehyde exposure linked to increased systemic health impairments and counteracting beneficial effects of selected antioxidants

ABSTRACT Background: Formaldehyde (FA) is a sensitizing agent that can produce an effective immune system response upon initial exposure. FA that can be used in many industries, medical and anatomical facilities, mainly cadaver-based gross anatomy laboratories, represent a risk to occupational health of professionals and students. The majority of FA exposures occur through inhalation, dermal, and eye contact. FA-induced effects are attributed to site-specific and dose-dependent health impairments in many organs and organ systems. Much progress has been reported on FA-induced health impairments in respiratory tract, but a comprehensive study in different organ systems and the reverse effects of some novel antioxidants is still lacking. This review explores the cytotoxic effects of FA and its role as key signaling molecule, site specific and or dose dependent effects of FA in nasal cavity, carcinogenic effects of FA exposure in nasopharynx, effects of FA in lung macrophage functions and development of pulmonary fibrosis, dose dependent reproductive and genetic effects of FA, neurotoxic effects of FA and potential risk of FA in some beauty salons and cosmetic products. In addition, this study shows the counteracting beneficial role of melatonin, Nigella sativa, rose oils, caffeic acid phenethyl ester (CAPE), vitamin E, and proanthocyanidins (PAs) against FA induced tissue damage.Methods: A comprehensive literature search highlighting the health impairments of FA and counteracting beneficial effects of promising antioxidants was conducted using PubMed, Google Scholar, and Medline Cochrane, to assemble relevant publications from open access international journals published only in English.Results: The search generated 411 articles of which 70 full research articles fulfilled the inclusion criteria and included in the review. The results of this study confirmed relentless toxic effects of FA exposure on various organs of human and other animals. Multiple findings also stated the efficacy of promising antioxidants against FA-induced tissue damage in animal models.Conclusion: Occupational exposure to FA is most likely due to inattention towards its side effects and lack of appropriate air filtering equipment or unmonitored concentration of FA in the working air. Therefore, re-evaluating the concentration of FA, proper ventilation, and assessment of working practices is highly recommended. Proper monitoring is also needed to improve compliance and protection of FA-based reproductive complications in females. Despite complete prevention is not viable, exposed personnel must be aware of FA-induced health effects and require assessing risks and acquiring practical measures in their working environment.