Neuropsychological Effects of “Perchloroethylene” on Exposed Dry Cleaning Workers Pouryaghoub Gh1, Sadeghniiat Haghighi Kh1, Sarreshtahdar H2 1 Dept of Occupational Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2 Occupational Health Unit, Deputy of Health Services, Shiraz University of Medical Sciences, Shiraz, Iran Corresponding Author’s Address: Dept of Occupational Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Email: pourya@tums.ac.ir Received: 4 Nov, 2008 Accepted: 1 June, 2008 Background and Objective: “Perchloroethylene” is a solvent widely used in dry cleaning industry. Various effects on liver, kidney, nervous and cardiovascular systems have been attributed to exposure to this solvent. In this study we assessed some of the neuropsychological effects of chronic exposure to perchloroethylene on exposed dry cleaning workers. Materials and Methods: 40 exposed and 40 non exposed workers were compared in this historical cohort study. The researchers collected the data using a questionnaire and a check list. Frequency of selected neuropsychological effects were evaluated and compared in each group by means of statistical software. Results: After adjustment for age and educational status, the frequency of depression in exposed group and non-exposed group was calculated to be %42/5 and %22/5 respectively (P=0/056). Frequency of memory loss was higher in exposed group (%27/5) compared to non-exposed group (%17/5) (P>0.05) and the frequency of repetitive checking was surprisingly higher in non-exposed group and this difference was statistically significant (P<0/05). Conclusion: The observed difference in “frequency of depression” in exposed and non exposed workers in our study was consistent with findings of previous studies. We were not able to demonstrate any statistically significant relation between perchloroethylene exposure and other neuropsychological effects. Our findings of “repetitive checking” was unexpectedly in contrast to the findings of previous studies.