Association Between Occupational Exposure to Formaldehyde and Cognitive Impairment

Area of Science:

• Environmental Health
• Neuroscience
• Occupational Health

Background:

• Formaldehyde exposure's impact on cognition is understudied in the general population.
• Previous research has not focused on middle-aged and young-old adults (≥45 years).

Purpose of the Study:

• To investigate the association between occupational formaldehyde exposure and cognitive impairment.
• To assess the long-term effects of formaldehyde on various cognitive domains.

Main Methods:

• Utilized the French CONSTANCES cohort (75,322 participants).
• Assessed cognitive function using a standardized battery of 7 tests.
• Estimated lifetime formaldehyde exposure via the French Job Exposure Matrix (Matgéné project).
• Employed modified Poisson regression models to analyze cognitive impairment (<25th percentile) and formaldehyde exposure metrics (duration, cumulative exposure index [CEI], recency).

Main Results:

• 8% of participants reported occupational formaldehyde exposure.
• Exposed individuals showed higher risks of global cognitive impairment (aRR 1.17; 95% CI 1.11-1.23).
• Cognitive deficits were observed across all tested domains, with dose-response relationships for exposure duration.
• Recent and past formaldehyde exposure demonstrated persistent detrimental effects on cognition, particularly for the Digit Symbol Substitution Test (DSST).

Conclusions:

• Occupational formaldehyde exposure has long-term detrimental effects on cognitive health.
• Cognitive deficits associated with formaldehyde exposure may not fully attenuate over time, especially in highly exposed individuals.
• Highlights the need for protective measures against formaldehyde in occupational settings.