Fluoride in hair as an indicator of exposure to fluorine compounds

Adult male Wistar rats were exposed to above-normal fluoride intake for 6 m onths: a) to HF by inhalation for 2 hr/day at a concentration of 8.7 +/- 5. 7 mg/m(3) and b) to sodium fluoride (NaF) in drinking water containing 20 m g F-/L. The fluoride content in dorsal hair, vertebrae L-2 - L-4, tibia, an d incisors was significantly increased in the exposed animals. More fluorid e accumulated by the inhalatory than by the oral route. Positive correlatio ns were found between the fluoride content in bone and in washed hair (r = 0.696) as well as in unwashed hair (r = 0.647). The results of this study i ndicate that hair may be a useful indicator of long-term exposure to fluori ne compounds.