Liver Function Tests in Mine Workers Exposed to Lead: An Occupational Cohort Study

Abstract

Background: Operational processes in lead mines cause workers to be occupationally exposed to lead particles, chronic exposure to lead can results innumerous health effects.Method: To know the effects of chronic lead exposure on liver function, the blood lead levels (BLL) and liver function tests of lead miners for 3- years (2017-2019) were followed and the obtained results were compared with those attained in the non-exposed group.Results: The BLL levels of the lead-mine workers were higher than with recommended level and the non-exposed group (24.15 and 6.35 µg dL-1, respectively, p<0.001). The findings indicated a positive and significant relationship between BLL and lactate dehydrogenase (r: 0.942, p<0.001), aspartate transaminase (r: 0.869, p<0.001), alkaline phosphatase (r: 0.9679, p<0.005), alanine transaminase (r: 0.9779, p<0.001), and bilirubin (r: 0.9169, p<0.001) levels, while we found a negative and significant correlation between BLL and triglyceride (r: -0.929, p<0.05), total protein (r: -0.896, p<0.001), albumin (r: -0.941, p<0.0021), and globulin (r: -0.863, p<0.001) levels. Moreover, no significant relationship was found between BLL and cholesterol, LDL, LDH, and BUN levels (p>0.05).Conclusions: This report showed that the chronic lead exposure is a major occupational hazard in lead mine workers. Despite the fact that the level of liver function parameters was in the normal range, the results of 3- years follow-up show a significant relationship between BLL and alteration of liver function parameters levels of lead miners. The study can be helpful in raising awareness of alteration in liver functions due to occupational exposure to lead.