Personality Traits in Miners with Past Occupational Elemental Mercury Exposure

Abstract

In this study, we evaluated the impact of long-term occupational exposure to elemental mercury vapor (Hg0) on the personality traits of ex-mercury miners. Study groups included 53 ex-miners previously exposed to Hg0 and 53 age-matched controls. Miners and controls completed the self-reporting Eysenck Personality Questionnaire and the Emotional States Questionnaire. The relationship between the indices of past occupational exposure and the observed personality traits was evaluated using Pearson’s correlation coefficient and on a subgroup level by machine learning methods (regression trees). The ex-mercury miners were intermittently exposed to Hg0 for a period of 7–31 years. The means of exposure-cycle urine mercury (U-Hg) concentrations ranged from 20 to 120 μg/L. The results obtained indicate that ex-miners tend to be more introverted and sincere, more depressive, more rigid in expressing their emotions and are likely to have more negative self-concepts than controls, but no correlations were found with the indices of past occupational exposure. Despite certain limitations, results obtained by the regression tree suggest that higher alcohol consumption per se and long-term intermittent, moderate exposure to Hg0 (exposure cycle mean U-Hg concentrations > 38.7 < 53.5 μg/L) in interaction with alcohol remain a plausible explanation for the depression associated with negative self-concept found in subgroups of ex-mercury miners. This could be one of the reason for the higher risk of suicide among miners of the Idrija Mercury Mine in the last 45 years.

Exposure to dietary mercury alters cognition and behavior of zebra finches

“…Taken together, these systematic behavioral differences support our overall hypotheses and predictions concerning behavioral changes: mercury exposure induces a behavioral phenotype of hyperactivity and decreased social dominance. These changes parallel some observations of humans who have been exposed to environmental mercury—where researchers have reported episodes of depression, anxiety, low sociality, and restlessness ( Bågedahl-Strindlund et al 1997 ; Kobal Grum et al 2006 ; Michaeli-Yossef et al 2007 ; Al-Batanony et al 2013 ). When we inspected the activity data more closely, we also noted, anecdotally, that mercury-exposed birds typically showed periods of almost complete inactivity followed by episodes of intense movements, further supporting the conclusion of restlessness or hyperactivity.…”

“…In birds, exposure to mercury has been linked with impaired motor function ( Bouton et al 1999 ). In humans, mercury-exposure is associated with alterations of emotional state and social tendencies ( Kobal Grum et al 2006 ) including depression, anxiety, and introversion ( Bågedahl-Strindlund et al 1997 ), and general restlessness ( Michaeli-Yossef et al 2007 ; Al-Batanony et al 2013 ). Given these patterns, we hypothesized that mercury would influence the general behavioral phenotype of our birds.…”

The burden of chronic mercury intoxication in artisanal small-scale gold mining in Zimbabwe: data availability and preliminary estimates

“…One study focusing on the mortality of workers chronically exposed to elemental mercury vapor did not find a higher mortality compared to controls [ 62 ]. Mortality attributable to high acute mercury exposure was confirmed [ 33 , 116 ], as were higher suicide rates amongst people exposed to mercury, these due to changes in personality [ 19 , 117 ]. Furthermore, there is a possible association with increased mortality from cardiovascular disease as a result of long-term exposure in European mercury mines [ 118 ].…”

L’exposition Aux Contaminants Environnementaux Comme Un Facteur De Risque Au Développement Des Troubles Intériorisés

“…Plusieurs études ont souligné davantage d'anxiété chez des adultes exposés au méthylmercure, comparativement à des adultes peu ou pas exposés (Aydin, Karaoglanoglu, Yigit, Keles, Kirpinar, & Seven, 2003;Haut, Morrow, Pool, Callahan, Haut, & Franzen, 1999;Powell, 2000;Zachi, Ventura, Faria, & Taub, 2007). Plusieurs études ont aussi observé davantage de symptômes dépressifs chez les adultes exposés au méthylmercure, comparativement au groupe témoin (Aydin et al, 2003;Corral et al, 2013;Grum et al, 2006;Haut et al, 1999;Zachi et al, 2007). Néanmoins, Barboni et ses collègues (2009) n'ont pas trouvé davantage de troubles intériorisés chez les adultes exposés au méthylmercure, comparativement au groupe témoin.…”