Mineradores gaúchos expostos a silício urinário: um estudo da nefrotoxicidade

Abstract

Introduction: Mining is an activity of great importance in Brazil, both due to the volume of production and the number of workers exposed to occupational risk agents, such as respirable crystalline silica, which is present in rocks and mineral dust. Chronic inhalation of these particles can cause serious lung diseases, such as silicosis, and affect other organs, such as the kidneys, suggesting possible nephrotoxicity. Objective: To preliminarily assess whether there are laboratory alterations in renal function among miners chronically exposed to crystalline silica. Methods: Approved by the CAAE of UFRGS (No. 53706121.6.1001.5347), the study included 13 miners exposed to silica and 13 unexposed workers. Blood and urine samples were collected for laboratory analysis, including quantification of silicon dioxide by inductively coupled plasma optical emission spectrometry (ICPOES). Renal function biomarkers, such as serum creatinine and urinary microalbuminuria, were evaluated using a semiautomatic biochemical analyzer (BS120 Mindray). The results were compared between the groups and with reference values. Results and Conclusions: Miners exposed to silica showed a significant increase in urinary microalbuminuria (corrected for g/creatinine) and serum creatinine, although both remained below reference values, suggesting early glomerular damage. Participants with biochemical alterations related to metabolic diseases (e.g., glycated hemoglobin, data not shown) were excluded. A significant reduction in urinary silicon was also observed among exposed participants, raising hypotheses about possible direct absorption of nanoscale silica or alterations in renal excretion mechanisms, considering the knowledge gap regarding the toxicodynamics of crystalline silica in tissues beyond the lungs. It is worth noting that common foods in the diet also contain silicon (cheese, oats, mineral water), which may interfere with the assessment. It is concluded that chronic occupational exposure to crystalline silica may contribute to renal alterations, with a potential nephrotoxic role. These are preliminary data, and the number of exposed miners should be increased to substantiate these hypotheses.