What levels of inorganic fluorides are safe for plants and animals that live in Canadian waters?
The Canadian Water Quality Guideline (CWQG) to protect freshwater life is 0.12 milligrams of inorganic fluoride per litre of water. The guideline is based on a number of scientific studies that examined the impacts inorganic fluorides have on the plants and animals that live in our lakes and rivers. If the level of inorganic fluorides measured in a lake or river is less than the guideline, one would not expect to see adverse health effects in even the most sensitive species. In places where the CWQG for inorganic fluorides is exceeded, an adverse effect on the environment may not necessarily occur. Rather, there is an increased chance of an effect depending on how high above the guideline the levels are, on which kinds of plants and animals live there, and on other characteristics of the water (e.g., how hard the water is). Further investigation at a particular site would be needed to actually determine whether or not there is a negative impact.