The Association between Blood Lead Level and Cognitive Functions among the Workers of a Lead Mine in Iran

Background: Workers are exposed to lead in many industries and mines.The present study aimed to determine lead levels and cognitive functions among workers of a lead mine in Iran. Materials and Methods:This cross-sectional study was conducted in Nain city in Isfahan Province, center of Iran, in 2022.The studied population consisted of 76 miners as the lead exposed group as well as a group of 76 office workers, working in the same mine, without any history of exposure to lead as the non-exposed group.Demographic information was collected using a questionnaire.The samples were analyzed using NIOSH techniques 8003 and 7082 to detect lead in the blood and breathing zone, respectively.The cognitive functions of the exposed and non-exposed groups were compared using the Wisconsin Card Sorting Test, digit span, Corsi block-tapping, Tower of London, and continuous performance tests.Results: The mean lead levels in the breathing zone and blood were significantly higher in the exposed group (0.08 0.06 mg/m 3 , 37.41 10.28 g/dl, respectively), compared to the nonexposed group (0.02 0.01 mg/m 3 , 12.57 4.27 g/dl, respectively).The total scores for all cognitive tests in the exposed group were significantly worse than those in the non-exposed group.Even after controlling for age, work history, smoking, education, and body mass index, there were still significant correlations between blood lead levels and cognitive abilities (p<0.05).Conclusion: According to the current study's findings, exposure to lead was associated with cognitive disorders.