Impact of occupational formaldehyde exposure on objective olfactory thresholds and olfaction-related quality of life

Formaldehyde (FA) is essential for tissue fixation, but its chronic effects on the olfactory system are concerning. This study investigated the impact of occupational FA exposure on objective olfactory function, nasal patency, and smell-related quality of life in pathology laboratory workers.

This cross-sectional case-control study included 68 participants (33 pathology workers, 35 controls). Assessments included otorhinolaryngological examination, Peak Nasal Inspiratory Flow (PNIF), and the Nasal Obstruction Symptom Evaluation (NOSE) scale. Objective olfactory function was evaluated using n-butanol threshold,identification tests, and the Connecticut Chemosensory Clinical Research Center (CCCRC) battery. Quality of life was measured using the Associated Factors in Olfaction-Related Quality of Life (ASOF) questionnaire.

Only 27.3% of pathology workers were normosmic, compared to 97.1% of controls. Total occupational FA exposure duration (months) correlated negatively with nbutanol thresholds and CCCRC scores, but not with identification. Weekly FA exposure correlated inversely with Olfaction-Related Quality of Life (ORQ) and positively with Subjective Olfactory Capability (SOC). No significant intergroup differences were found in NOSE or PNIF values.

Occupational FA exposure significantly impairs objective olfactory thresholds and adversely affects smell-related quality of life. The discrepancy between objective loss and subjective capability highlights the need for regular chemosensory screening and improved air quality standards in laboratories.