Assessment of Early Nephrotoxicity in Workers Exposed to Trichloroethylene Using NGAL and KIM-1 Biomarkers

This study evaluated early renal effects of chronic occupational exposure to mixed organic solvents among automotive spray painters by integrating urinary trichloroacetic acid (TCA) as an internal exposure marker with serum neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) as early tubular injury biomarkers. In this cross-sectional comparison of exposed workers and controls, urinary TCA was quantified as a surrogate of trichloroethylene metabolism, and serum NGAL and KIM-1 were measured alongside routine biochemical indices, creatinine, and estimated glomerular filtration rate (eGFR). Exposed workers showed significantly elevated NGAL and KIM-1 despite within limits creatinine and eGFR. TCA demonstrated strong linear associations with NGAL and KIM-1, while other solvent metabolites showed weaker relationships. Findings indicate that chronic solvent exposure produces measurable subclinical tubular injury, underscoring the limitations of creatinine-based monitoring and supporting the incorporation of NGAL and KIM-1 into occupational health surveillance.