Fluoride health hazards

Are caustic materials processed If these are released and contact people either as a vapor or liquid severe health hazards result. For example, uranyl fluoride forms hydrofluoric acid in the lungs. 

There are instances, for example with aluminum and copper, where even phytotoxic concentrations pose no health hazard to animals (143). Lead contamination, on the other hand, is considered a bigger hazard to man and animal by accidental ingestion than to plants because it is largely unavailable (insoluble) to the latter (100). Fortunately, the element is largely removed by simple rinsing (144). Fluoride, in contrast to lead, is absorbed readily in the free form and tends to be phytotoxic at extremely low concentrations (145). 

Fluoride-related health hazards are associated with the use of fluoride-contaminated water for drinking and cooking. This corresponds only to 2-4 L per capita per day. Fluoride removal in rural areas in LDCs, where centralized water treatment and distribution facilities are unavailable, should consequently be carried out at a household level and the system applied should be simple and affordable. In this regard, tea bag POU system becomes handy. Although this kind of system has not been specifically reported for water defluoridation, it has been tested for arsenic [37,107], It is therefore a short-term potential technique worth considering. In this technique, adsorption medium is placed in a tea bag-like packet, which is subsequently placed in a bucket of water to be treated. To ensure faster defluoridation kinetics, the bag should be swirled inside the water. It therefore operates like a batch reactor and hence requires a relatively longer adsorption time to achieve the permissible levels. Since the swirling motion is supposed to be human-powered, the technique would require a material with very fast kinetics or very fine adsorption media. 

The dark side of hydrofluoric acid is its toxicity and corrosiveness. Aqueous and anhydrous HF readily penetrate the skin, and, because of its locally anesthetizing effect, even in very small quantities can cause deep lesions and necroses [4, 5]. An additional health hazard is the systemic toxicity of fluoride ions, which interfere strongly with calcium metabolism. Resorption of HF by skin contact (from a contact area exceeding 160 cm ), inhalation, or ingestion leads to hypocalcemia with very serious consequences, for example cardiac arrhythmia. 

Controversy exists about the health hazards of aluminum fluoride. On the one hand, the compound would appear to pose a relatively minor risk when ingested because it is so insoluble in water and other solvents. If it does not dissolve in the body, it can not get into the blood... 

Most authorities agree that aluminum fluoride does not pose a health hazard when ingested in moderate amounts because of its low solubility. The compound may pose a threat if inhaled or deposited on the skin, however. In modest amounts, it may produce skin and eye irritations that range from moderate to severe irritation of the nose, throat, and lungs, that may include nosebleeds and asthma-like... 

Environmental Health and Safety News Article 1 Hydrogen Fluoride Cylinder Hazard University of Maryland, July 16, 1999. 

Phosphate rock dust, fluorides, acid, and radioactive elements are the main health hazards in a phosphoriir acid plant. The threshold limit value (TLV) of industrial exposure to hydrogen fluoride for daily intake has been established at 5-6 mg/Nm however, considering other inputs from drinking water and food, the reasonable limit of daily intake has been established at levels of 2 mg/ day of fluorides ingestion. 

As described previously, phosphate rock dust, fluorides, acids, ammonia, and radioactive elements are the main health hazards in fertilizer production. Fertilizer products are of low hazard however, ammonium nitrate storage areas must be kept free of organic materials, Coating materials such as crystalline silica are hazardous if inhaled. 

Radon, Rn At. no. 86, at. wt 222, mp—71°C, bp -61.8°C. Radon is an intermediate radioactive decay product of Ra. Rn, the most stable isotope of radon, is obtained as a gas from aqueous solutions of RaCl2 and has been used as a radiation source and as a gaseous tracer. It is a considerable hazard in uranium mines. In some areas, radon in basements and in ground water is a potential health hazard because of its radioactivity. The ground state electronic configuration of radon is [Xe]4f " 5d °6s 6p. Because radon is intensely radioactive, the chemistry of radon has only been investigated on the tracer scale. Radon forms compounds, particularly a fluoride (likely RnF2), and solid adducts between the fluoride and Lewis acid fluorides. 

While nobody can guarantee the safety of any human measure under all circumstances, the safety of the adjustment of drinking water fluoride to about 1 ppm is supported by so large and so manifold scientific material and clinical data that any health hazard with this measure is extremely improbable. Specific claims of such hazards have been few and inadequately supported. 

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