Plants fluoride damage

Fluoride. Fluoride damage to plants has been observed and studied in Western Europe for well over a century, and during the past 50 years has received considerable attention in the United States (6, 10, 13, 17). Plant damage is attributed primarily to hydrogen fluoride (HF) contamination, but silicon tetrafluoride and other gaseous forms released by industry are also toxic. HF is much more abundant in polluted areas than the other fluoride compounds. 

Hydrogen fluoride Catalyst in some petroleum refining, etching glass, silicate extraction by-product in electrolytic production of aluminum Petroleum, primary metals, aluminum Strong irritant and corrosive action on all body tissue damage to citrus plants, effect on teeth and bones of cattle from eating plants... 

The movement of fluoride through the atmosphere and into a food chain illustrates an air-water interaction at the local scale (<100 km) (3). Industrial sources of fluoride include phosphate fertilizer, aluminum, and glass manufacturing plants. Domestic livestock in the vicinity of substantial fluoride sources are exposed to fluoride by ingestion of forage crops. Fluoride released into the air by industry is deposited and accumulated in vegetation. Its concentration is sufficient to cause damage to the teeth and bone structure of the animals that consume the crops. 

Heavy metals on or in vegetation and water have been and continue to be toxic to animals and fish. Arsenic and lead from smelters, molybdenum from steel plants, and mercury from chlorine-caustic plants are major offenders. Poisoning of aquatic life by mercury is relatively new, whereas the toxic effects of the other metals have been largely eliminated by proper control of industrial emissions. Gaseous (and particulate) fluorides have caused injury and damage to a wide variety of animals—domestic and wild—as well as to fish. Accidental effects resulting from insecticides and nerve gas have been reported. 

The committee notes that the electrode damage may become more severe when feeds containing fluorine and chlorine are processed. In the fluoride transfer test discussed earlier, the titanium electrodes were severely corroded and the Pt coating was pitted or peeling off. This more severe damage would be unacceptable during full-scale plant operation. 

Acute symptoms of injury from various pollutants in different horticultural and agronomic groups are visible on the affected plant. Symptom expressions produced include chlorosis, necrosis, abscission of plant parts, and effects on pigment systems. Major pollutants which produce these injuries include sulfur dioxide, peroxyacetyl nitrate (PAN), fluorides, chlorides, nitrogen dioxide, ozone, and particulate matter minor pollutants are ethylene, chlorine, ammonia, and hydrogen chloride. Symptoms of acute injury are often used to identify pollutant source and to estimate agricultural damage. 

This recommendation by the ACGIH (American Conference of Governmental Industrial Hygienists) and OSHA (Occupational Health and Safety Act) comes with an additional stipulation that exposures should not exceed 0.3mg/m, even for short periods. A primary environmental concern in the operation of a phosphorus furnace is with potential losses of dissolved and suspended elemental phosphorus in water, since even low concentrations are toxic to freshwater and marine animal life. Care is also taken to avoid losses of fluoride to air or freshwater, which are more likely to occur during process upsets, since fluorides may cause damage to adjacent plant life or freshwater organisms [20]. 

Fluorine is another potentially-toxic trace element which is dispersed by atmospheric pollution and it has long been recognised that damage to plants occurs and that there is a hazard to man and farm stock, in the vicinity of industrial plants processing fluoride-containing minerals. Such plants include factories for the production of aluminium, superphosphates and compound fertilisers based on the liberation of phosphoric acid from rock phosphate. In October 1976, ten cows had to be destroyed on two farms in the vicinity of the British Aluminium Company s aluminium smelter at Invergorden in the north of Scotland, and problems of fluoride toxicity have been commonly associated elsewhere with the production of aluminium. 

The removal of fluorine compounds from industrial exhaust gases is of increasing importance as an air-pollution-control measure. Fluorides may be emitted fipom many processes and actual vegetation damage or cattle fluorosis have reportedly resulted from the qperation of plants producing aluminum, phosphate fertilizer, iron, enamel, and bricks. The two qpera-... 

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