Developmental toxicity of sodium fluoride measured during multiple generations

Area of Science:

• Toxicology
• Developmental Biology
• Environmental Health

Background:

• Sodium fluoride (NaF) has been used for drinking water fluoridation since the 1940s.
• Limited multigenerational studies exist on NaF's long-term effects.

Purpose of the Study:

• To assess the multigenerational toxicological effects of NaF in rats.
• To identify potential adverse effects across three generations.

Main Methods:

• Rats (F0) received NaF (0-250 ppm) in drinking water for 10 weeks before mating.
• Cesarean sections and litter observations were conducted on F0 and F1 generations.
• F2 fetuses underwent detailed skeletal and soft-tissue evaluation.

Main Results:

• Decreased fluid intake at higher NaF doses (175-250 ppm) due to palatability.
• No dose-related effects on feed consumption, body weight, or reproductive parameters.
• Significantly reduced hyoid bone ossification in F2 fetuses at 250 ppm NaF.

Conclusions:

• The study identified 250 ppm NaF as an effect level based on hyoid bone ossification.
• NaF did not exhibit significant adverse effects on most reproductive and developmental parameters in a multigenerational rat study.