TOXIC EFFECTS OF CHRONIC FLUORIDE INGESTION ON THE UPPER GASTROINTESTINAL-TRACT

In a prospective case controlled study, we evaluated the adverse effec ts of long-term fluoride ingestion on the gastrointestinal tract. Ten patients with otosclerosis who were receiving sodium fluoride 30 mg/da y for a period of 3-12 months, and 10 age- and sex-matched healthy vol unteers were included. They were all evaluated clinically and subjecte d to a real time ultrasound examination, upper gastrointestinal endosc opy, and biopsies from the gastric antrum and duodenum. The biopsies w ere subjected to a rapid urease test as well as light and electron mic roscopic examinations. Ionic fluoride was estimated in the serum, urin e, and drinking water using an ION 85 Ion Analyzer. Seven subjects (70 %) ingesting fIuoride had abdominal pain, vomiting, and nausea. Petech iae, erosions, and erythema were seen on endoscopy in all the subjects , but not in the controls. Histological examination of the gastric ant ral biopsy showed chronic atrophic gastritis in all the subjects but i n only one (10%) healthy volunteer. Scanning electron microscopic exam ination showed ''cracked-clay'' appearance, scanty microvilli, surface abrasions, and desquamated epithelium in the subjects ingesting fluor ide, but not in the controls. We conclude that long-term fluoride inge stion is associated with a high incidence of dyspeptic symptoms as wel l as histological and electron microscopic abnormalities.