Fluoride levels and biochemical assessments in cattle accidentally exposed to hydrofluoric acid in Korea

On September 27, 2012, an explosion from hydrofluoric acid occurred in Gumi city of Gyeongbuk province, Republic of Korea, exposing livestock animals nearby to Hydrofluoric acid (HF). This study aimed at evaluating the HF exposure among cattle raised near the accident site by determining the fluoride ion (F^-1) levels and other biochemical parameters in the animals' urine and serum. The study groups included 90 cattle raised on farms near the accident site and, as controls, 21 cattle raised on a farm more than 100 km away from the accident site. Urine and blood serum samples were taken from 10% to 20% of the cattle on each farm that were present 17 days after the accident. The F^-1 concentrations in the samples were analysed by the fluoride-ion-selective electrode method or a biochemistry analyser. The mean F^-1 levels in the cattle serum samples (expressed as mg/L) were 0.23 (100 m), 0.15 (500 m), 0.23 (800 m), 0.11 (900 m), 0.07 (1.2 km), 0.16 (1.5 km), and 0.10 in the control group. The mean F^-1 levels in the cattle urine samples (expressed as F^-1 mg/g creatinine) were 27.8 (100 m), 24.4 (500 m), 11.1 (800 m), 16.3 (900 m), 3.02 (1.2 km), 9.16 (1.5 km), and 3.58 in the control group. The mean±SD concentrations of calcium ions in serum (expressed as mg/dL) were 9.72±0.41 (100 m), 9.54±0.57 (500 m), 8.31±0.44 (800 m), 9.06±0.40 (900 m), 8.36±0.89 (1.2 km), 9.13±0.98 (1.5 km), and 10.48±1.43 in the control group. The serum and urine F^-1 levels in cattle exposed to HF decreased with the distance from the accident site, suggesting that the relative F^-1 levels in urine after normalization through concentration of urinary creatinine could be a more reliable biomarker for HF exposure in cattle than the urine F^-1 level alone.