Evaluation of kidney injury biomarkers in an adult Mexican population environmentally exposed to fluoride and low arsenic levels

Abstract Fluoride (F) is a toxicant widely distributed in the environment. Experimental studies have shown kidney toxicity from F exposure. However, co-exposure to arsenic (As) has not been considered, and epidemiological information remains limited. We evaluated the association between F exposure and urinary kidney injury biomarkers and assessed As co-exposure interactions. A cross-sectional study was conducted in 239 adults (18–77 years old) from three communities in Chihuahua, Mexico. Exposure to F was assessed in urine and drinking water, and As in urine samples. We evaluated the urinary concentrations of albumin (ALB), cystatin-C (Cys-C), kidney injury molecule 1 (KIM-1), clusterin (CLU), osteopontin (OPN), and trefoil factor 3 (TFF-3). The estimated glomerular filtration rate (eGFR) was calculated using serum creatinine (Creat) levels. We observed a positive correlation between water and urine F concentrations (ρ = 0.7419, p