According to a French cohort study, published in the journal Neurology, occupational formaldehyde exposure is associated with cognitive deficits at relatively young ages.

Researchers assessed 75,322 individuals who were a part of the CONSTANCES cohort, of whom 6,047 had had exposure to formaldehyde during their work life. They noted that people aged 45 years and above had a higher risk of global cognitive impairment if they were exposed to formaldehyde at work (adjusted RR 1.17). The higher risk of impairment extended across all cognitive domains. High duration of exposure as well as high lifetime dose were both tied to worse cognition. Workers with exposure to formaldehyde for 22 years or over were found to have a 21% higher risk of global cognitive impairment compared to those who had never been exposed (adjusted RR 1.21)… (Medpage Today)