Human Toxicity, Environmental Impact and Legal Implications of

HUMAN TOXICITY, ENVIRONMENTAL IMPACT AND LEGAL IMPLICATIONS OF WATER FLUORIDATION
spinning caddis fly larvae and upstream-migrating adult salmons, appear to
be more sensitive to fluoride toxicity than estuarine and marine animals.
Because, in soft waters with low ionic content, a fluoride concentration as low
as 0.5 mg F-/l can adversely affect invertebrates and fishes, safe levels below
this fluoride/l concentration are recommended in order to protect freshwater
animals from fluoride pollution.
Camargo further observed that aquatic organisms living in soft waters may
be more adversely affected by fluoride pollution than those living in hard or
seawaters because the bio-availability of fluoride ions is reduced with
increasing water hardness. It was further found that fluoride can either inhibit
or enhance the population growth of algae, depending upon fluoride
concentration, exposure time and algal species.
It is clear therefore that much greater research is needed on the lifecycle
impacts of fluoride on the environment; in particular any potential impacts on
ecological receptors such as fisheries, given that 243 fluoridation plants are
located in Ireland with many in sensitive fisheries catchment areas.
Additional research has demonstrated that fluorides released into marine
environments have been shown to accumulate in some aquatic organisms. 100
It has been further demonstrated that foods characteristically high in fluoride
content are certain types of seafood (1.9-28.5 mg/kg). 101 In a study by
Hemens and Warwick 102 toxic effects due to fluorosis were observed in
species of mussel, mullet, crab and shrimp in an estuary where waste from an
aluminium plant was released.
Hemens and Warick also noted the apparent lack of information on bioconcentration
in aquatic organisms and bio-magnification in food chains
which the researchers observed would be helpful in assessing the importance
of bioaccumulation of fluorides as a route of human exposure to this
contaminant.
4.3 Fluoride as a Pollutant in Soil.
Fluoride is a pollutant that is present in sewage sludge and processed
waterwater sludge where fluoridated waste has been used in the
manafacturing process. 103
Sewage and processed sludge has been and continues to be applied to
land in Ireland. While the State has an obligation to protect public health and
the environment from the anticipated adverse effects of this pollutant on the
100 Toxicological Profile For Fluorides, Hydrogen Fluoride, And Fluorine, Agency for
Toxic Substances and Disease Registry U.S. Public Health Service April 1993.
101 Kumpulainen J, Koivistoinen P. 1977. Fluorine in foods. Residue Rev 68:37-55.
102 Hemens J, Warwick RJ. 1972. Effects of fluoride on estuarine organisms. Water Res
6:1301-1308.
103 U.S EPA Technical Support Document for the Round Two Sewage Sludge Pollutants,
Office of Water, EPA-822-R-96-003, August 1996.
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