7. What are the risks posed by fluorides?
- 7.1 What are the risks to humans?
- 7.2 What are the risks to the environment?
7.1 What are the risks to humans?
Fluoride has both positive and negative effects on human health, but there is a narrow range between intakes which are beneficial and those which are detrimental. It is important to take into account all sources of exposure to fluoride, including through drinking water and foodstuffs.
It is difficult to determine dose-response relationships between fluoride exposure and different adverse effects. This is due to the limited information available on total fluoride exposure, particularly with respect to fluoride intake and absorption.
The most serious effect is the accumulation of fluoride in bones from long-term excessive exposure and the potential for skeletal fluorosis and bone fractures. At total intakes of 14 mg fluoride/day, there is clear evidence of skeletal fluorosis and an increased risk of bone fractures; at total intake levels above about 6 mg fluoride/day the evidence is suggestive of an increased risk of adverse effects on bone. More...
7.2 What are the risks to the environment?
Natural fluoride concentrations in freshwater are usually lower than those expected to cause toxicity in aquatic organisms, which may, however, be adversely affected by nearby discharges from human activities.
The release of fluoride from human activities poses a risk to local sensitive plant species. However, damage to local terrestrial plant communities is often difficult to attribute to the presence of fluoride alone as other atmospheric pollutants also have an impact on vegetation.
Concentrations of fluoride in vegetation near fluoride emission sources, such as aluminium smelters, can be higher than the lowest dietary effect concentration reported for mammals in laboratory experiments.
Fluorosis has been reported in domesticated animals and in livestock due to the uptake of fluoride from fluoride-rich mineral supplements and drinking water. Furthermore, there is a potential risk from the ingestion of fluoride-contaminated pasture after the long-term use of phosphate fertilizers containing high levels of fluoride. Fluoride-induced effects, such as lameness and tooth damage, have also been reported in wild mammals close to fluoride natural emission sources, such as volcanoes, and those linked to human activities. More...