Fluoride pollution

A.K.M. Arnesen, G. Abrahamsen, G. Sandvik, T. Krogstad, Aluminium-smelters and fluoride pollution of soil and soil solution in Norway, Sci. Total Environ. 163 (1995) 39-53. 

Aluminum reduction plants have also caused local forest destruction. In Montana, fluoride pollution killed or severely injured ponder osa pine and lodge pole pine on 8 fcm (2000A) surrounding a plant. In Washington, ponderosa pine mortality and morbidity resulted over a 130 km (50 mi ) area in the vicinity of an aluminum plant. 

However, the fact that fluorides are (i) associated with the application of some phosphate fertilisers that many leach into surface waters and shallow ground water and (ii) by-product of the phosphate fertiliser industry which are the primary sources of fluoride pollution call upon the need of receptors that are able to interact with both anions. Calix[4]pyrrole and most of the derivatives have... 

Ando M, Tadano M, Asanuma S, Tamura K, Matsushima S, Watanabe T, Kondo T, Sakurai S, Ji R, Liang C, Cao S (1998) Health effects of indoor fluoride pollution from coal burning in China. Environ Health Perspect, 106(5) 239-244. 

Plate 19. Heavy injury on leaves of sycamore (Acer pseudoplatanus L.) maple showing marginal necroses which are not due to fluoride pollution because of low fluoride contents in leaves. Lack of magnesium as a rc.sult of soil acidification by acid rain may be the reason. Haard Forest, North to Recklinghausen, W. Germany, 1982. 

Ding, J., Z. Zheng, and D. Cao. 1987. Fluoride pollution caused by phosphate fertilizer plant and its effect on children s health. Fluoride 20 154—161. 

Halides.—Marier41 has drawn attention to recent evidence that the levels of both monofluoroacetate and fluorocitrate in crops appear to be enhanced by fluoride pollution of the atmosphere. 

Pomazkina, L.V., Radnaev, A.B.D., Kotova, L.G. and Petrova, I.G. (2001) The transformation and balance of nitrogen in fluoride-polluted agroecosystems on gray forest soils of the Baikal region. Eurasian Soil Science, 34, 645-650. 

Naturally occurring F associated with hydrous minerals has low mobility because it is occluded in structures. Airborne fluoride pollutants (from smelters, rock phosphate fertilizer factories, etc.) are, in contrast, easily dissolved on contact with the soil. These forms of fluoride can be bioaccumulated by plants before leaching, sorption, or precipitation processes have a chance to lower solubility. 

Clinical manifestations of fluorosis often occur in the hard tissues of animals, such as bones and teeth, as a result of long-term intake of elevated levels of fluoride, mainly due to industrial fluoride pollution. Evidence also indicates harmful effects of fluoride on soft tissues such as lung, kidney, testis, fiver and brain. Generally, fluorine, in the form of the fluoride ion (F ), is present in soil and water in low concentrations, but it may cause a threat to public and occupational health when its presence in the environment increases due to natural or anthropogenic sources. Excessive intake of F via drinking water is an endemic problem in a number of countries including China, India,... 

Some industrial plants, for example aluminium smelters, emit fluorides, In the past, there have been cases of fluoride pollution affecting the teeth and joints of cattle. The Union Carbide Corporation has invented a process for removing fluorides from waste gases. It involves the reaction ... 

Scurfield, 1960 [229] has reported that as much as 150 km of Pintis ponderosa forest has been affected by fluoride pollution of the atmosphere. 

Silicon tetrafluoride gas, SiF4, a gaseous fluoride pollutant produced during some steel and metal smelting operations that employ CaF2, fluorspar. Fluorspar reacts with silicon dioxide (sand), releasing S1F4 gas ... 

Air pollutants that present a hazard to livestock, therefore, are those that are taken up by vegetation or deposited on the plants. Only a few pollutants have been observed to cause harm to animals. These include arsenic, fluorides, lead, mercury, and molybdenum. 

The harmful effects of air pollutants on human beings have been the major reason for efforts to understand and control their sources. During the past two decades, research on acidic deposition on water-based ecosystems has helped to reemphasize the importance of air pollutants in other receptors, such as soil-based ecosystems (1). When discussing the impact of air pollutants on ecosystems, the matter of scale becomes important. We will discuss three examples of elements which interact with air, water, and soil media on different geographic scales. These are the carbon cycle on a global scale, the sulfur cycle on a regional scale, and the fluoride cycle on a local scale. 

The third category for interactions is high dose (III). The effects produced by this level of interaction can be seen by the casual observer. The result of high-dose exposure is destruction or severe injury of the forest system. High-dose conditions are almost always associated with point source emissions. The pollutants most often involved are SO2 and hydrogen fluoride. Historically, the most harmful sources of pollution for surrounding forest ecosystems have been smelters and aluminum reduction plants. 

Hundreds of chemical species are present in urban atmospheres. The gaseous air pollutants most commonly monitored are CO, O3, NO2, SO2, and nonmethane volatile organic compounds (NMVOCs), Measurement of specific hydrocarbon compounds is becoming routine in the United States for two reasons (1) their potential role as air toxics and (2) the need for detailed hydrocarbon data for control of urban ozone concentrations. Hydrochloric acid (HCl), ammonia (NH3), and hydrogen fluoride (HF) are occasionally measured. Calibration standards and procedures are available for all of these analytic techniques, ensuring the quality of the analytical results... 

Modem smelters using good industrial practices are able to achieve the following in terms of pollutant loads (all values are expressed on an annualized basis) hydrogen fluoride, 0.2 to 0.4 kg/t total fluoride, 0.3 to 0.6 kg/t particulates, 1 kg/t sulfur dioxide, 1 kg/t and nitrogen oxides, 0.5 kg/t. CF4 emissions should be less than 0.1 kg/t. 

The technology is primarily applicable to the removal of inorganic fumes, vapors, and gases (e.g., chromic acid, hydrogen sulfide, ammonia, chlorides, fluorides, and SOj) volatile organic compounds (VOC) and particulate matter (PM), including PM less than or equal to 10 micrometers ( m) in aerodynamic diameter (PM,q), PM less than or equal to 2.5 m in aerodynamic diameter (PMj 5), and hazardous air pollutants (HAP) in particulate form (PM ap)-... 

Reduction of cnviromncntal pollution requires lower energy use and new technology to decrease emission of gases such as sulfur dioxide and carbon dioxide, and to prevent toxic fluoride, heavy metal, and radioactive wastes from discharging into the environment. 

Dusts produced by quarrying and fluorides emanating from oil refineries are typical pollutants, which need regular monitoring. A range of portable equipment for the identification and quantification of toxic and other gases can be used on an ad hoc basis. 

Painting wastewater generally consists of quench water. Wastewater from this operation is generally less toxic than wastewater from the other general operations normally, only the following pollutants are expected to exceed 10 pg/L oil and grease, fluorides, TSS, iron, zinc, bis(2-ethyl-hexyl) phthalate, and diethyl phthalate. 

Some innovating treatment technologies may be introduced in the treatment of wastewater generated in the aluminum fluoride industry to make its effluent safer. The ion exchange process can be applied to the clarified solution to remove copper and chromium. At a very low concentration, these two pollutants can be removed by xanthate precipitation.24 A combination of lime and ferric sulfate coagulation will effectively reduce arsenic concentration in the wastewater. 

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