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Trace Elements in Abiotic and Biotic Environments
TABLE 15.3

Excessive Levels of Fluorine in Plants Grown in Contamination Sites (mg/kg)

Pollution Source
Country
Plant/Part
Range/Maximum
Mine wastes
United Kingdom
Grass and tops
130–5450
Al industry
Australia
Shrubs and leaves
150–500
Czech Republic
Grass and tops
1330
Norway
Birch and leaves
230
United Kingdom
Lichens
27–241
Phosphate rock processing
Canada
Tree and foliage
71–900
United States
Sagebrush and tops
100–360
China-clay industry
United Kingdom
Grass and tops
788–1543
Fiberglass plant
Canada
Vegetation and foliage
71–900
Source: From Kabata-Pendias, A., Trace Elements in Soils and Plants, 4th ed., CRC Press, Boca Raton
FL, 2011.
plants accumulation of airborne F, but the most important are F concentration in
the atmosphere and the duration of exposure. Some amounts of F remain on the leaf
surfaces and can be easily washed off with water.
Mean F contents in cereal grains vary within the range of 0.2–5.5 mg/kg, with the
lowest in oats and the highest in barley. Range of F in forage legumes and grasses is
1.4–7.8 mg/kg and 3–6.8 mg/kg, respectively (Kabata-Pendias 2011).
Plants do not require F for metabolic processes. But it may be toxic, when is
absorbed by leaves. Fluorine is considered to be the most phytotoxic among other
airborne pollutants. In general, elevated F contents resulted in a lower plant growth
and yield reduction. The most important harmful effects of airborne F are as follows:
r Decrease of oxygen uptake and respiratory disorder
r Decrease of assimilation
r Reduction of chlorophyll
r Inhibition of starch synthesis
r Inhibition of pyrophosphate function
r Injured cell organelles and cell membranes
r Disturbance of DNA and RNA
r Synthesis of fluorooctate, hazardous F compound
It can be generalized that susceptible plants could be injured by foliar F concentrations at the range of 20–150 mg/kg, intermediate plants may tolerate F contents at
about 200 mg/kg, and highly tolerant plants did not suffer even with F content up to
500 mg/kg.
Excessive F contents in food and fodder plants are of the greatest concern because
most of the F contamination can easily enter the food and fodder chains. The commonly reported ranges for F contents in fodder plants vary from 20 to 50 mg/kg.