Multigenerational evaluation of sodium fluoride in rats

Since the mid 1940s, fluoride has been added to tap water in American commu nities in an effort to reduce the incidence of dental caries in the populat ion. When the levels of fluoride in drinking water were tested and set, wat er was the only measurable source of fluoride for most communities. Now, ad ults and children ingest fluoride with foods and beverages prepared with fl uoridated water, and they are exposed to fluoride-containing dental product s. As a result, exposure to fluoride is greater than had been anticipated. In the early 1990s, the existing reproductive studies were reviewed in seve ral reports and were considered to be inadequate to determine potential rep roductive or developmental hazards. The effects of sodium fluoride ingestio n at 0, 25, 100, 175 or 250 ppm in drinking water measured in rats througho ut three generations are reported here. Feed and fluid consumption, body we ights and clinical signs were recorded at regular intervals. Decreased flui d consumption observed at 175 and 250 ppm was attributed to decreased palat ability and did not affect reproduction. No cumulative effects were observe d in the three generations. Mating, fertility and survival indices were not affected. organ-to-body-weight ratios and organ-to-brain weight ratios wer e not affected. Sodium fluoride up to 250 ppm did not affect reproduction i n rats. Published by Elsevier Science Ltd.