Deposition of fluorides increases the fluoride content of vegetation, and eventually soil. Fluoride is very rapidly fixed by mineral soils so even where the concentration increases substantially, there is no increase in uptake by plants. Effects on plants are caused by direct uptake of Hydrogen Fluoride from the air, not by deposition on soil. In arable soils the use of phosphate fertilisers (which contain from 0.5-3% F), are a much more significant source than air pollution. Ploughing mixes deposited fluoride so there is a neglible increase in concentration, even near major sources. Therefore, there is no effect of deposited atmospheric F on arable crops.
|Critical Load/ Level|
No estimate available