Association between cadmium and lead exposure and kidney stone formation in fuel station workers: A case-control study in North Basra

Abstract

Background: Cadmium and lead are two examples of nephrotoxic heavy metals. Environmental and occupational exposure to these heavy metal can be linked to nephrolithiasis, which is becoming a more prevalent condition worldwide. There is evidence of increased exposure in the vulnerable population of fuel station workers. Limited information on this condition is available from Iraq. Objective: This study aims to examine the associations of the biomarkers of the cadmium and lead exposure with the kidney stones’ odds among fuel station workers in North Basra, Iraq. Materials and Methods: A total of 50 subjects, 25 patients with a verified diagnosis of kidney stones and 25 healthy controls, were enrolled in the study. The subjects’ venous blood was drawn. The quantitative determination of cadmium concentration was performed through atomic absorption spectrometry, and the quantitative detection of lead and renal function markers-with chemist’s method using biochemical analyzers. Statistical data processing was carried by independent sample t-test. Results: The kidney stone group exhibited significantly elevated serum cadmium (1.85 ?g/L vs. 0.45 ?g/L, p<0.01) and blood lead levels (5.85 ?g/dL vs. 2.50 ?g/dL, p<0.001) compared to controls. A significant decrease in uric acid was also observed in patients (4.62 mg/dL vs. 5.17 mg/dL, p=0.029). No significant differences were found in urea, creatinine, or total protein levels. Conclusion: The findings demonstrate a strong association between elevated cadmium and lead exposure and the presence of kidney stones among fuel station workers, highlighting these heavy metals as significant occupational risk factors for nephrolithiasis.