Effects of high fluoride content in livestock drinking water on milk samples of different cattle in endemic area of Pakistan: risk assessment for children.

Fluoride in trace quantity is beneficial for human beings, serving to strengthen the apatite matrix of skeletal tissues and teeth, whereas high intake causes adverse impacts. In the present study, the effect of fluoride-contaminated drinking water of livestock on the milk samples of different cattle, belonging to a fluoride-endemic area (Tharparkar, Pakistan), was studied. In milk samples of different cattle (cows, camels, sheep, and goats), free and bound fluoride forms and its total (free (F-) + bound (F-)) contents were measured by ion-selective electrode. The concentration of fluoride in drinking water of livestock was also analyzed, as found in the range of 11.8-33.5 mg/L. The concentration of total fluoride in the milk samples of sheep, goats, cows, and camels were observed in the range of 1.72-2.43, 1.40-2.03, 0.835-1.41, and 0.425-0.897 mg/L, respectively. The resulted data indicated that the concentration of fluoride was higher in the milk samples of smaller cattle (sheep and goat), as compared to cow and camel. The fluoride in milk samples of all cattle appeared dominantly in free form. The percentage values of bound fluoride in the milk samples of sheep, goats, and cows were found to be 6.76, 11.6, and 19.7% in total, respectively, while in camel milk, the percentage was below the detection limit. The estimated daily intake of fluoride contents on consuming different types of milk by children age ranged 1.0 to 3.0 years was evaluated. Graphical abstract ᅟ.