Biological monitoring of mercury exposure in individuals referred to a toxicological center in Venezuela

People in developing countries are often considered at greater risk of mercury (Hg) poisoning due to a variety of factors including a lack of awareness regarding their occupational risks. Individuals requiring urine mercury (U-Hg) analysis at the Center for Toxicological Investigations of the University of Carabobo (CITUC), between 1998 and 2002 were studied to identify demographic characteristics associated to U-Hg levels. The studied population included individuals with a history of exposure (or related exposures) to Hg processes, and was comprised of 1159 individuals (65 children, 1094 adults) ages 0.58–79 years old, mean 36.63±12.4. Children's geometric mean U-Hg levels were 2.73 μg/g Creatinine (Ct) and in adults 2.55 μg/g Ct. The highest frequency of adults' occupations were shipyard workers (35.47%), dentists (23.5%), lab technicians (11.43%), dental employees 10.42% and miners (10.2%). Chemical laboratory technicians had the highest mean U-Hg (4.46 μg/g Ct). Mean U-Hg levels in female adults (3.45 μg/g Ct) were statistically superior to levels in male adults (2.15 μg/g Ct). Two of the 172 women in reproductive age, had U-Hg levels higher than 78 μg/g Ct. Individuals from Falcon State were found to have the highest mean U-Hg (4.53 μg/g Ct). U-Hg levels higher than permissible limits were found in only 2 states (Carabobo and Bolivar) with a total of 24 cases. Although the results of this investigation were highly variable, the findings can be used to examine circumstances which influence mercury toxicity trends, and possibly used in future studies working to identify Hg exposures.