CARBOHYDRATES, a group of substances which includes the sugars, starches, and celluloses, along with the many varied products, either found in nature or prepared in the laboratory, which are closely related to them chemically.
The simplest carbohydrates function as polyhydroxyaldehydes or ketones containing from 3 to 9 carbon atoms, although, as will be seen later, these assume a cyclic character. This proves that the arrangement of the six carbon atoms of glucose does not involve a branched chain of carbon atoms.
The aldehydic functions are further illustrated by the action of such reagents as hydroxylamine and phenylhydrazine, which give respectively glucose-oxime and glucose-phenylhydrazone. The aldehydic formula for glucose explains satisfactorily most of the observations mentioned above, but it is impossible to account on this basis for the existence of two isomeric crystalline a- and 13-forms of the sugar or of its simple derivatives. Stereochemistry of the Sugars.—To visualize the arrange ment in space of the sugar molecule, it is imperative to know how a simple chain of six carbon atoms is disposed.
Only thus is it possible to realize that the expression Otherwise it may be erroneously considered that the former can be made to be identical with the latter by merely revolving the second carbon atom round the first. Breath Direct injection into GC GC-FID No data Trotter et al.
Rural air Air passed through silica gel coated with HPLC-UV No data Shepson et al.
Fresh fruit Vacuum distillation followed by solvent extraction HRGC-MS No data Takeoka et al. 8)      Check normal values – see if there are any irregularities – remember nitrites show infection! This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the United Nations Environment Programme, the International Labour Organization or the World Health Organization. Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals. The International Programme on Chemical Safety (IPCS), established in 1980, is a joint venture of the United Nations Environment Programme (UNEP), the International Labour Organization (ILO) and the World Health Organization (WHO).
The Inter-Organization Programme for the Sound Management of Chemicals (IOMC) was established in 1995 by UNEP, ILO, the Food and Agriculture Organization of the United Nations, WHO, the United Nations Industrial Development Organization, the United Nations Institute for Training and Research and the Organisation for Economic Co-operation and Development (Participating Organizations), following recommendations made by the 1992 UN Conference on Environment and Development to strengthen cooperation and increase coordination in the field of chemical safety. The World Health Organization welcomes requests for permission to reproduce or translate its publications, in part or in full. Publications of the World Health Organization enjoy copyright protection in accordance with the provisions of Protocol 2 of the Universal Copyright Convention. The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
The mention of specific companies or of certain manufacturers’ products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not mentioned. The Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Germany, provided financial support for, and undertook the printing of this publication. Every effort has been made to present information in the criteria monographs as accurately as possible without unduly delaying their publication. A detailed data profile and a legal file can be obtained from the International Register of Potentially Toxic Chemicals, Case postale 356, 1219 Châtelaine, Geneva, Switzerland (telephone no. This publication was made possible by grant number 5 U01 ES02617-15 from the National Institute of Environmental Health Sciences, National Institutes of Health, USA, and by financial support from the Federal Ministry for the Environment, Nature conservation and Nuclear Safety, Germany. The first Environmental Health Criteria (EHC) monograph, on mercury, was published in 1976, and since that time an ever-increasing number of assessments of chemicals and of physical effects have been produced. Since its inauguration, the EHC Programme has widened its scope, and the importance of environmental effects, in addition to health effects, has been increasingly emphasized in the total evaluation of chemicals. The original impetus for the Programme came from World Health Assembly resolutions and the recommendations of the 1972 UN Conference on the Human Environment. The recommendations of the 1992 UN Conference on Environment and Development and the subsequent establishment of the Intergovernmental Forum on Chemical Safety with the priorities for action in the six programme areas of Chapter 19, Agenda 21, all lend further weight to the need for EHC assessments of the risks of chemicals. The criteria monographs are intended to provide critical reviews on the effects on human health and the environment of chemicals and of combinations of chemicals and physical and biological agents. In the evaluation of human health risks, sound human data, whenever available, are preferred to animal data. The EHC monographs are intended to assist national and international authorities in making risk assessments and subsequent risk management decisions.
Since the inception of the EHC Programme, the IPCS has organized meetings of scientists to establish lists of priority chemicals for subsequent evaluation. If an EHC monograph is proposed for a chemical not on the priority list, the IPCS Secretariat consults with the cooperating organizations and all the Participating Institutions before embarking on the preparation of the monograph. The order of procedures that result in the publication of an EHC monograph is shown in the flow chart on the next page. The draft document, when received by the RO, may require an initial review by a small panel of experts to determine its scientific quality and objectivity. The Task Group members serve as individual scientists, not as representatives of any organization, government or industry. The three cooperating organizations of the IPCS recognize the important role played by nongovernmental organizations. All individuals who as authors, consultants or advisers participate in the preparation of the EHC monograph must, in addition to serving in their personal capacity as scientists, inform the RO if at any time a conflict of interest, whether actual or potential, could be perceived in their work. When the Task Group has completed its review and the RO is satisfied as to the scientific correctness and completeness of the document, the document then goes for language editing, reference checking and preparation of camera-ready copy. All Participating Institutions are informed, through the EHC progress report, of the authors and institutions proposed for the drafting of the documents. A WHO Task Group on Environmental Health Criteria for Fluorides met at the Institute of Environmental Health and Engineering of the Chinese Academy of Preventive Medicine in Beijing, People’s Republic of China, on 28 May – 1 June 2001. The efforts of all who helped in the preparation and finalization of the monograph are gratefully acknowledged. This document focuses on environmental exposure to fluoride derived mostly from inorganic sources and its effects on humans, animals and other biota. Hydrogen fluoride (HF) is a colourless, pungent liquid or gas that is highly soluble in organic solvents and in water, in which it forms hydrofluoric acid. The most common procedure used to quantify free fluoride anion is the fluoride ion-selective electrode.
Fluorides are released into the environment naturally through the weathering and dissolution of minerals, in emissions from volcanoes and in marine aerosols. The transport and transformation of fluoride in water are influenced by pH, water hardness and the presence of ion-exchange materials such as clays.
The transport and transformation of fluoride in soil are influenced by pH and the formation of predominantly aluminium and calcium complexes. Terrestrial plants may accumulate fluorides following airborne deposition and uptake from soil. Fluoride levels in surface waters vary according to location and proximity to emission sources. Airborne fluoride exists in gaseous and particulate forms, which are emitted from both natural and anthropogenic sources. Fluorides can be taken up by aquatic organisms directly from the water or to a lesser extent via food. Fluoride levels in terrestrial biota are higher in areas with high fluoride levels from natural and anthropogenic sources.
Fluoride accumulates in the bone tissue of terrestrial vertebrates, depending on factors such as diet and the proximity of fluoride emission sources. Fluoride is ubiquitous in the environment; therefore, sources of drinking-water are likely to contain at least some small amount of fluoride. Although individual exposure to fluoride is likely to be highly variable, the inhalation of airborne fluoride generally makes a minor contribution to the total intake of this substance. Occupational exposure to fluoride via inhalation or dermal contact likely occurs in individuals involved in the operation of welding equipment or in the processing of aluminium, iron ore or phosphate ore.
In humans and laboratory animals, the absorption of ingested fluoride into the general circulation occurs primarily in the stomach and intestine and is dependent upon the relative aqueous solubility of the form consumed.
Fluoride is rapidly distributed by the systemic circulation to the intracellular and extracellular water of tissues; however, in humans and laboratory animals, approximately 99% of the total body burden of fluoride is retained in bones and teeth. Effects on the skeleton, such as inhibition of bone mineralization and formation, delayed fracture healing and reductions in bone volume and collagen synthesis, have been observed in a variety of studies in which rats received fluoride orally for periods of 3–5 weeks.
Reproductive or developmental effects were not observed in recent studies in which laboratory animals were administered fluoride in drinking-water. Epidemiological investigations on the effects of fluoride on human health have examined occupationally exposed workers employed primarily in the aluminium smelting industry and populations consuming fluoridated drinking-water. The relationship between the consumption of fluoridated drinking-water and morbidity or mortality due to cancer has been examined in a large number of epidemiological studies, performed in many countries. Cases of skeletal fluorosis associated with the consumption of drinking-water containing elevated levels of fluoride continue to be reported. Evidence from several ecological studies has suggested that there may be an association between the consumption of fluoridated water and hip fractures.
Epidemiological studies show no evidence of an association between the consumption of fluoridated drinking-water by mothers and increased risk of spontaneous abortion or congenital malformation. Signs of inorganic fluoride phytotoxicity (fluorosis), such as chlorosis, necrosis and decreased growth rates, are most likely to occur in the young, expanding tissues of broadleaf plants and elongating needles of conifers. Aluminium smelters, brickworks, phosphorus plants and fertilizer and fibreglass plants have all been shown to be sources of fluoride that are correlated with damage to local plant communities. The original findings of fluoride effects on mammals were from studies in the field on domestic animals such as sheep and cattle. Fluoride has both positive and negative effects on human health, but there is a narrow range between intakes that are associated with these effects. There is little information to characterize the dose–response relationships for the different adverse effects. The most serious effect is the skeletal accumulation of fluoride from long-term excessive exposure to fluoride and its effect on non-neoplastic bone disease — specifically, skeletal fluorosis and bone fractures.
In the freshwater environment, natural fluoride concentrations are usually lower than those expected to cause toxicity in aquatic organisms. Concentrations of fluoride in vegetation in the vicinity of fluoride emission sources, such as aluminium smelters, can be higher than the lowest dietary effect concentration reported for mammals in laboratory experiments. Fluoride has both beneficial and detrimental effects on human health, with a narrow range between the intakes at which these occur. Effects on the teeth and skeleton may be observed at exposures below those associated with the development of other organ- or tissue-specific adverse health effects.
Skeletal fluorosis is a crippling disability that has a major public health and socioeconomic impact, affecting millions of people in various regions of Africa, China and India.
Intake of fluoride in water and foodstuffs is the primary causative factor for endemic skeletal fluorosis. There are few data from which to estimate total exposure to and the bioavailability of fluoride, and there are inconsistencies in reports on the characterization of its adverse effects.
Excess exposure to bioavailable fluoride constitutes a risk to aquatic and terrestrial biota.
Fluoride-sensitive species can be used as sentinels for the identification of fluoride hazards to the environment. There is a need to improve knowledge on the accumulation of fluoride in organisms and on how to monitor and control this. Methods employed for the quantification of fluoride in biological samples and environmental media generally rely on the detection of fluoride ion (F–). Appropriate sample preparation is a critical step in the accurate quantification of fluoride, especially where only the free fluoride ion is measured.
Hydrogen fluoride (hydrofluoric acid) is an important industrial compound, with an estimated annual world consumption in excess of 1 million tonnes (Greenwood & Earnshaw, 1984). Industrially, calcium fluoride is the principal fluoride-containing mineral used (WHO, 1984). Data concerning the total annual consumption or production of sodium fluoride worldwide were not identified.
Fluorosilicic acid is an aqueous solution that is most commonly manufactured as a co-product from the manufacture of phosphate fertilizers.
Sodium hexafluorosilicate, like fluorosilicic acid, is used in the fluoridation of drinking-water. More than 110 tonnes of sulfur hexafluoride are imported into Canada annually (Government of Canada, 1993). Fluorapatite, an important calcium- and fluoride-containing mineral, is used as a source of phosphates in the fertilizer industry (Neumüller, 1981). Phosphate fertilizers are the major source of fluoride contamination of agricultural soils.
Available quantitative information concerning the release of fluoride into the environment (air, water and soil) from industrial sources is limited. The fate of inorganic fluorides in the atmosphere is primarily influenced by vaporization, aerosol formation, wet and dry deposition and hydrolysis (Environment Canada, 1994). Atmospheric fluorides emitted from both natural and anthropogenic sources may be in gaseous or particulate form (Kirk & Lester, 1986).
Fluorides adsorbed on particulate matter in the atmosphere are generally stable and are not readily hydrolysed, although they may be degraded by radiation if they persist in the atmosphere (US NAS, 1971). Hydrofluoric acid is approximately 5 orders of magnitude less soluble than hydrochloric acid and will therefore be degassed from marine aerosols more readily than hydrochloric acid.
Schotte (1987) used a dispersion model to predict the formation and behaviour of the fog formed from the release of hydrogen fluoride to the atmosphere. Based upon available data, inorganic fluoride compounds, with the exception of sulfur hexafluoride, are not expected to remain in the troposphere for long periods or to migrate to the stratosphere. Fluoride in aerosols can be transported over large distances by wind or as a result of atmospheric turbulence. Atmospheric fluorides may be transported to soils and surface waters through both wet and dry deposition processes (US NAS, 1971). Wet deposition of fluoride may occur as washout from plumes below cloud or rainout of particulates taken up by clouds.
The dry deposition rate for fluoride in the Agra region of India was highest between December and June, when atmospheric fluoride concentrations were highest (Saxena et al., 1994). Several studies have been conducted to determine whether fluoride in rainwater was derived from anthropogenic emissions or natural sources such as sea salt cycling.


The ratio between total fluorine and chloride in rainwater from Wales was greater than the ratio in seawater (Neal et al., 1990). We present our 7 butterbeer cooking options especially popular in recent years among young people.
These simpler mem bers, the sugars, may be regarded as the units of which the more complex carbohydrates are built up. The oxidation can be shown to involve the second carbon atom and the formation of the osazone may be summarized thus: Glycuronic Acid.
It has been shown that three carbon atoms are linked together in such a manner that they are inclined at an angle of 109° 28', thus: If six such atoms are joined then the fifth and sixth will approach near in space to the first, that is, the chain of atoms curls round on itself. In the study of sugar chemistry, spherical models of the atoms are essential aids to the realization of these factors of the distribution of groups in three dimensional space. Start to pass urine, and pass the first part into the toilet, then, without stopping the flow, catch some of the middle of the sample in a bottle. You also want to know if it was taken in the last 2 hours – a crude way to know if it is recent is to see if it is warm! The overall objectives of the IPCS are to establish the scientific basis for assessment of the risk to human health and the environment from exposure to chemicals, through international peer review processes, as a prerequisite for the promotion of chemical safety, and to provide technical assistance in strengthening national capacities for the sound management of chemicals.
The purpose of the IOMC is to promote coordination of the policies and activities pursued by the Participating Organizations, jointly or separately, to achieve the sound management of chemicals in relation to human health and the environment. Applications and enquiries should be addressed to the Office of Publications, World Health Organization, Geneva, Switzerland, which will be glad to provide the latest information on any changes made to the text, plans for new editions, and reprints and translations already available. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. In the interest of all users of the Environmental Health Criteria monographs, readers are requested to communicate any errors that may have occurred to the Director of the International Programme on Chemical Safety, World Health Organization, Geneva, Switzerland, in order that they may be included in corrigenda. Subsequently, the work became an integral part of the International Programme on Chemical Safety (IPCS), a cooperative programme of UNEP, ILO and WHO.
Animal and in vitro studies provide support and are used mainly to supply evidence missing from human studies.
They represent a thorough evaluation of risks and are not, in any sense, recommendations for regulation or standard setting. A designated staff member of IPCS, responsible for the scientific quality of the document, serves as Responsible Officer (RO). Once the RO finds the document acceptable as a first draft, it is distributed, in its unedited form, to well over 150 EHC contact points throughout the world who are asked to comment on its completeness and accuracy and, where necessary, provide additional material. Their function is to evaluate the accuracy, significance and relevance of the information in the document and to assess the health and environmental risks from exposure to the chemical.
Representatives from relevant national and international associations may be invited to join the Task Group as observers. After approval by the Director, IPCS, the monograph is submitted to the WHO Office of Publications for printing. A comprehensive file of all comments received on drafts of each EHC monograph is maintained and is available on request. The group reviewed the draft document and the peer review comments and revised and further updated the draft, including the evaluation of the risks for human health and the environment from exposure to fluorides.
Aitio of the IPCS central unit was responsible for the scientific aspects of the monograph, and Ms M. Data on hydrogen fluoride, calcium fluoride, sodium fluoride, sulfur hexafluoride and silicofluorides are covered, as these compounds are considered to be the most relevant of the inorganic fluorides on the basis of quantities released to the environment, environmental concentrations and toxicological effects on living organisms.
Calcium fluoride (CaF2) is a colourless solid that is relatively insoluble in water and dilute acids and bases. Fluorides are also released into the environment via coal combustion and process waters and waste from various industrial processes, including steel manufacture, primary aluminium, copper and nickel production, phosphate ore processing, phosphate fertilizer production and use, glass, brick and ceramic manufacturing, and glue and adhesive production. It is also used in etching semiconductor devices, cleaning and etching glass, cleaning brick and aluminium and tanning leather, as well as in commercial rust removers. Atmospheric fluorides can be transported over large distances as a result of wind or atmospheric turbulence or can be removed from the atmosphere via wet and dry deposition or hydrolysis. Fluoride released as gaseous and particulate matter is deposited in the general vicinity of an emission source, although some particulates may react with other atmospheric constituents. Airborne gaseous and particulate fluorides tend to accumulate within the surface layer of soils but may be displaced throughout the root zone, even in calcareous soils.
Dental products such as toothpaste, mouthwash and fluoride supplements have been identified as significant sources of fluoride. For adults, the consumption of foodstuffs and drinking-water is the principal route for the intake of fluoride.
Soluble fluorides are almost completely absorbed from the gastrointestinal tract; however, the extent of absorption may be reduced by complex formation with aluminium, phosphorus, magnesium or calcium. There was a statistically significant trend of an increased incidence of osteosarcomas in male rats with increasing exposure to fluoride. Although fluoride has been shown to increase the frequency of mutations at specific loci in cultured mouse lymphoma and human lymphoblastoid cells, these mutations are likely due to chromosomal damage rather than point mutations. In a number of analytical epidemiological studies of workers occupationally exposed to fluoride, an increased incidence of lung and bladder cancer and increased mortality due to cancer of these and other sites have been observed. There is no consistent evidence of an association between the consumption of controlled fluoridated drinking-water and increased morbidity or mortality due to cancer. The prevalence of dental caries is inversely related to the concentration of fluoride in drinking-water.
A number of factors, such as nutritional status and diet, climate (related to fluid intake), concomitant exposure to other substances and the intake of fluoride from sources other than drinking-water, are believed to play a significant role in the development of this disease. Other studies, however, including analytical epidemiological investigations, have not supported this finding.
Other epidemiological investigations of occupationally exposed workers have provided no reasonable evidence of genotoxic effects or systemic effects upon the respiratory, haematopoietic, hepatic or renal systems that may be directly attributable to fluoride exposure per se. In laboratory studies, fluoride seems to be toxic for microbial processes at concentrations found in moderately fluoride polluted soils; similarly, in the field, accumulation of organic matter in the vicinity of smelters has been attributed to severe inhibition of microbial activity by fluoride. The induction of fluorosis has been clearly demonstrated in laboratory, greenhouse and controlled field plot experiments. Vegetation in the vicinity of a phosphorus plant revealed that the degree of damage and fluoride levels in soil humus were inversely related to the distance from the plant. Exposure to all sources of fluoride, including drinking-water and foodstuffs, is important. In particular, there are few data on total exposure, particularly with respect to intake and fluoride absorption. However, aquatic organisms might be adversely affected in the vicinity of anthropogenic discharges. The release of fluoride from anthropogenic sources is associated with damage to local terrestrial plant communities, but it is often difficult to attribute these effects to fluoride alone, due to the presence of other atmospheric pollutants. Very high intakes have been observed in areas worldwide in which the environment is rich in fluoride and where groundwater high in fluoride is consumed by humans. In some regions, the indoor burning of fluoride-rich coal also serves as an important source of fluoride.
Data on hydrogen fluoride, calcium fluoride, sodium fluoride, sulfur hexafluoride and silicofluorides are emphasized, as these compounds are considered the most relevant of the inorganic fluorides on the basis of quantities released to the environment, environmental concentrations and toxicological effects on living organisms.
7664-39-3) is a colourless, pungent, acrid liquid or gas with a melting point of -83 °C and a boiling point of 19.5 °C. 7789-75-5) is a colourless solid with a melting point of 1403 °C and a boiling point of 2513 °C.
7681-49-4) is a colourless to white solid with high melting (988–1012 °C) and boiling (1695 °C) points. 16961-83-4), which is also known as hexafluorosilicic acid, hydrofluorosilicic acid, fluosilicic acid or fluorosilicic acid, is a colourless solid that is highly soluble in water. 16893-85-9), also known as disodium hexafluorosilicate or sodium silicofluoride, is a colourless solid that is moderately soluble in water. For analyses involving biological materials, the most accurate method is the microdiffusion technique, such as the acid-hexamethyldisiloxane (HMDS) diffusion method by Taves (1968), since methods involving acid or alkali digestion may not convert all complex inorganic and organic fluorides into an ionic form that can be conveniently measured (Venkateswarlu, 1983). Estimates of the annual global release of hydrogen fluoride from volcanic sources through passive degassing and eruptions range from 60 to 6000 kilotonnes, of which approximately 10% may be introduced directly into the stratosphere (Symonds et al., 1988).
Hydrogen fluoride is manufactured from calcium fluoride and is used mainly in the production of synthetic cryolite, aluminium fluoride (AlF3), motor gasoline alkylates and chlorofluorocarbons; however, the demand for chlorofluorocarbons is decreasing as a result of efforts to restrict their use. It is used widely for the fluoridation of drinking-water, in which it hydrolyses to release fluoride ions.
It is normally completely dissolved in water prior to dosing, when it hydrolyses to give fluoride ions. This substance is used extensively as an insulation and current interruption medium in electrical switchgear, such as power circuit breakers, in various components in electrical substations (Government of Canada, 1993) and as a protective inert gas over molten metals, such as magnesium and aluminium (Neumüller, 1987). Fluoride is released into the environment via exhaust fumes, process waters and waste from various industrial processes, including steel manufacture, primary aluminium, copper and nickel production, phosphate fertilizer production and use, glass, brick and ceramic manufacturing, and glue and adhesive production.
The relative contribution of various anthropogenic sources to total emissions of fluoride to air, water and soil in Canada are estimated at 48% for phosphate fertilizer production, 20% for chemical production, 19% for aluminium production, 8% for steel and oil production and 5% for coal burning (Government of Canada, 1993). Non-volatile inorganic fluoride particulates are removed from the atmosphere via condensation or nucleation processes.
Gaseous forms include hydrogen fluoride, silicon tetrafluoride (SiF4), fluorosilicic acid and sulfur hexafluoride. Hydrofluoric acid is expected to be depleted in aged marine aerosols, and this may be a significant source of hydrogen fluoride in the troposphere (Brimblecombe & Clegg, 1988). The distance travelled is determined by the deposition velocity of both the gaseous hydrogen fluoride and the fluorides in particulate form.
The washout process is of particular importance for the removal of soluble fractions such as hydrogen fluoride aerosols at short distances from the source. Barnard & Nordstrom (1982) stated that fluoride should not be regarded as a cyclical sea salt, because the fluoride concentrations in rain from areas with no local anthropogenic emissions were not correlated with sea salt availability (as determined by the sodium concentration). This implied enrichment of total fluorine relative to chloride, reflecting complex fractionation processes in the transport of fluorine from the sea to the atmosphere and back to land as precipitation. Its members play an all-important part in the lives of plants and animals, as structural elements and in the maintenance of functional activity.
They reveal exceed ingly complex possibilities of isomerism and many of them occur in amorphous colloidal forms. The simplest sugars are termed monosaccharides and their nomenclature is based on the value of n in the above formula.
Glucose may be prepared readily from starch or from cane sugar by the action of dilute acids. Even more important, is the recognition that when two other atoms are attached to each of these carbon atoms, these also will make an angle of 1o9° 28'. The times down the side of the bottle are the time from 0, not the time between each result. Can also be due to overflow proteinuria (myeloma), connective tissue disorders, DM, hypertension. Other publications have been concerned with epidemiological guidelines, evaluation of short-term tests for carcinogens, biomarkers, effects on the elderly and so forth. In this manner, with the strong support of the new partners, the importance of occupational health and environmental effects was fully recognized.
It is mandatory that research on human subjects is conducted in full accord with ethical principles, including the provisions of the Helsinki Declaration. The contact points, usually designated by governments, may be Participating Institutions, IPCS Focal Points or individual scientists known for their particular expertise.
A summary and recommendations for further research and improved safety aspects are also required. While observers may provide a valuable contribution to the process, they can speak only at the invitation of the Chairperson. At this time, a copy of the final draft is sent to the Chairperson and Rapporteur of the Task Group to check for any errors.
The Chairpersons of Task Groups are briefed before each meeting on their role and responsibility in ensuring that these rules are followed. The use of fluoride-containing pesticides as well as the controlled fluoridation of drinking-water supplies also contribute to the release of fluoride from anthropogenic sources. Calcium fluoride is used as a flux in steel, glass and enamel production, as the raw material for the production of hydrofluoric acid and anhydrous hydrogen fluoride, and as an electrolyte in aluminium production.
Fluoride compounds, with the exception of sulfur hexafluoride, are not expected to remain in the troposphere for long periods or to migrate to the stratosphere.
However, no information was identified concerning the biomagnification of fluoride in aquatic or terrestrial food-chains. The distribution and deposition of airborne fluoride are dependent upon emission strength, meteorological conditions, particulate size and chemical reactivity.
The clay and organic carbon content as well as the pH of soil are primarily responsible for the retention of fluoride in soils. If fluoride is taken up through the root, its concentrations are often higher in the root than in the shoot, due to the low mobility of fluoride in the plant. Tea leaves are particularly rich in fluoride; the amount of fluoride in brewed tea is dependent upon the concentration of soluble fluoride in the tea leaves, the level of fluoride in the water used in its preparation and the length of the brewing period. In areas of the world in which coal rich in fluoride is used for heating and food preparation, the inhalation of indoor air and consumption of foodstuffs containing increased levels of fluoride also contribute to elevated intakes. There is partial to complete absorption of gaseous and particulate fluorides from the respiratory tract, with the extent of absorption dependent upon solubility and particle size. In infants, about 80–90% of a fluoride dose is retained; in adults, the corresponding figure is approximately 60%.
In general, however, there has been no consistent pattern; in some of these epidemiological studies, the increased morbidity or mortality due to cancer can be attributed to the workers’ exposure to substances other than fluoride.
The prevalence of dental fluorosis is highly associated with the concentration of fluoride, with a positive dose–response relationship. Skeletal fluorosis may develop in workers occupationally exposed to elevated levels of airborne fluoride; however, only limited new information was identified. In the other study, an increased incidence of fractures was observed in one age group of women exposed to fluoride in drinking-water in a non-dose-dependent manner. Inorganic fluoride toxicity to freshwater fish appears to be negatively correlated with water hardness (calcium carbonate) and positively correlated with temperature.


A large number of the papers published on fluoride toxicity to plants concern glasshouse fumigation with hydrogen fluoride.
A few studies have been carried out in which the fluoride exposures have been via the soil.
There are still some areas reporting fluorosis incidents in livestock due to uptake of fluoride-rich mineral supplements and drinking-water. It is relatively insoluble in water — approximately 3000 times less soluble in water than sodium fluoride (McIvor, 1990) — as well as in dilute acids and bases (Neumüller, 1981). Open ashing methods may result in the loss of volatile fluoride compounds or of fluoride itself at temperatures in excess of 550 °C, or they may result in contamination with extraneous fluoride (Venkateswarlu, 1975; Campbell, 1987).
Other minerals, such as fluorapatite (Ca5(PO4)3F) and calcium fluoride, are dissolved more slowly (Kabata-Pendias & Pendias, 1984). Hydrogen fluoride is also used in the synthesis of uranium tetrafluoride (UF4) and uranium hexafluoride (UF6), both of which are used in the nuclear industry (Neumüller, 1981). When used for the fluoridation of drinking-water, fluorosilicic acid should meet appropriate standards, such as those published by the American Water Works Association and the European Committee for Standardization or other approved schemes for drinking-water chemicals. When used for drinking-water fluoridation, it too should meet appropriate standards of purity for drinking-water chemicals. Over 90% of the total amount of sulfur hexafluoride imported into Canada is used in the production of magnesium; the remainder is used in electrical switchgear (Government of Canada, 1993). The use of fluoride-containing pesticides as well as the fluoridation of drinking-water supplies also contribute to the release of fluoride from anthropogenic sources.
In the Netherlands, 93% of total fluoride emissions to air, water and soil are derived from phosphate ore production and use, with smaller amounts emitted via mineral processing (2%), the metal industry (4%) and "other industry" (1%) (Sloof et al., 1989).
Particulate forms include sodium aluminium fluoride (cryolite), aluminium fluoride, calcium fluoride, sodium hexafluorosilicate, lead fluoride (PbF2) and calcium phosphate fluoride (fluorapatite).
Similarly, approximately 60% of the fluorides in the atmosphere in the Netherlands are in the gaseous state (Sloof et al., 1989).
The transportation of particles with a diameter greater than 10 µm is determined by the particle falling speed, and the dispersion of such particles is generally limited to the immediate vicinity of the source.
It is assumed that all irreversibly soluble gases such as hydrogen fluoride are washed out during showers.
Mass balance considerations suggested that the majority of fluoride samples in the rainwater were of anthropogenic origin. Cane sugar, glucose, fructose, and the vari ous forms of starch and cellulose may be cited as typical rep resentatives. For these reasons, their study has provided problems of exceptional interest and difficulty, and in spite of the long-continued efforts of chemists, it is only within recent years that definite knowledge has been obtained concern ing the internal structure of even the simplest members.
Hence to por tray such a figure on a plane surface, such as this page, is impos sible, and some pictorial convention must be devised.
The EHC monographs have become widely established, used and recognized throughout the world. Worldwide data are used and are quoted from original studies, not from abstracts or reviews. The first draft, prepared by consultants or, more usually, staff from an IPCS Participating Institution, is based initially on data provided from the International Register of Potentially Toxic Chemicals and from reference databases such as Medline and Toxline. Generally, some four months are allowed before the comments are considered by the RO and author(s). The composition of the Task Group is dictated by the range of expertise required for the subject of the meeting and by the need for a balanced geographical distribution.
Observers do not participate in the final evaluation of the chemical; this is the sole responsibility of the Task Group members.
The document was sent for peer review to the IPCS contact points and additional experts on fluoride. Sulfur hexafluoride (SF6) is a colourless, odourless, inert gas that is slightly soluble in water and readily soluble in ethanol and bases.
Based on available data, phosphate ore production and use as well as aluminium manufacture are the major industrial sources of fluoride release into the environment.
Sodium fluoride is used in the controlled fluoridation of drinking-water, as a preservative in glues, in glass and enamel production, as a flux in steel and aluminium production, as an insecticide and as a wood preservative. Sulfur hexafluoride has an atmospheric residence time ranging from 500 to several thousand years.
The concentration of fluoride in food products is not significantly increased by the addition of superphosphate fertilizers, which contain significant concentrations of fluoride (1–3%) as impurities, to agricultural soil, due to the generally low transfer coefficient from soil to plant material. Infants fed formula receive 50–100 times more fluoride than exclusively breast-fed infants. The symptoms of acute fluoride intoxication include lethargy, violent and erratic movement and death. Plant communities near an aluminium smelter showed differences in community composition and structure due partly to variations in fluoride tolerance. Incidents involving domesticated animals have originated both from natural fluoride sources, such as volcanic eruptions and the underlying geology, and from anthropogenic sources, such as mineral supplements, fluoride-emitting industries and power stations. Consequently, plant uptake via this pathway is relatively low, and leaching of fluoride through soil is minimal. Furthermore, there is a potential risk from fluoride-contaminated pasture and soil ingestion due to the long-term use of phosphate fertilizers containing fluoride as an impurity.
It is also used in etching semiconductor devices, cleaning and etching glass, cleaning brick and aluminium and tanning leather, as well as in petrochemical manufacturing processes.
Calcium fluoride is used as a flux in steel, glass and enamel production and as the raw material for the production of hydrofluoric acid and anhydrous hydrogen fluoride (Neumüller, 1981). The total amounts of hydrogen fluoride released to air, surface water, underground injection and land in the USA during 1999 were 33 000, 7.7, 1800 and 64 tonnes, respectively. Globally, hydrogen fluoride and inorganic fluoride particulates (sodium and calcium fluoride) account for approximately 75% and 25%, respectively, of inorganic fluorides present in the atmosphere (Health Council of the Netherlands, 1990). As the fog mixes with more air, it will begin to warm up and it may rise, depending on the ambient air temperature and the relative humidity. Smaller particles are less restricted by the falling speed and can be transported over larger distances (Sloof et al., 1989).
The rainout process is more important for the removal of fluorides distant from the source when the plume is situated at least partially in the clouds.
The source of the release was uncertain, since the total fluorine concentration in baseflow waters was not significantly higher than stormflow values. Rich products that were lush and soft even the next day, the dough must be added diluted potato starch.
Their industrial importance may be estimated from the fact that amongst the undertakings directly dependent on carbohydrate materials are the cotton industry, the manufac ture of paper, the artificial silk industries, certain branches of the explosives industry, brewing and the manufacture of power alcohol. The commonest and most important representatives of the two classes of sugars are glucose (an aldohexose) and fructose (a ketohexose) and the reactions of these two will now be considered in greater detail. From its aqueous solution it separates in warty masses containing one molecule of water of crystallization, m.p. Thus in representing the H and OH attached to a carbon atom it is always assumed that the reader sees each individual carbon atom projected into the plane of the printed page, but the H and OH group attached to this carbon atom will emerge upwards from the page at the above angle. Both published and unpublished reports are considered, and it is incumbent on the authors to assess all the articles cited in the references.
A second draft incorporating comments received and approved by the Director, IPCS, is then distributed to Task Group members, who carry out the peer review, at least six weeks before their meeting.
The authors, in collaboration with the IPCS Secretariat, revised the document based on the comments received. Sulfur hexafluoride is used extensively in various electronic components and in the production of magnesium and aluminium.
For all soils, it is the soluble fluoride content that is biologically important to plants and animals. Small amounts of airborne particulate fluoride can enter the plant through the epidermis and cuticle.
However, a recent study suggests that, given the right soil conditions and application of sufficient fluoride as an impurity in phosphate fertilizers to soils, plant uptake of fluoride can be increased.
The ingestion of dentifrice by young children makes a significant contribution to their total intake of fluoride. In most studies in which fluoride was administered orally to rodents, there was no effect upon sperm morphology or the frequency of chromosomal aberrations, micronuclei, sister chromatid exchange or DNA strand breaks. However, it must be noted that, in the field, one of the main problems with the identification of fluoride effects is the presence of confounding variables such as other atmospheric pollutants. Symptoms of fluoride toxicity include emaciation, stiffness of joints and abnormal teeth and bones. Fluoride-induced effects, such as lameness and tooth damage, have also been reported in wild mammals close to anthropogenic sources. Calcium fluoride is also used as a molten electrolyte for the separation of oxygen and alumina in aluminium production. Total amounts of fluorine released to air, surface water and land were 39, 24 and 500 tonnes, respectively (US EPA, 1999). Fluorine and the silicon fluorides are hydrolysed in the atmosphere to form hydrogen fluoride. Another necessary condition, which helps to make the cakes taste even better - well sprouted dough. Reduction of gluconolactone in aqueous solution with sodium amalgam and dilute acid gives glucose, whilst on oxidation with nitric acid both glucose and its lactone yield saccharic acid (V.). Following an updating at the end of 2000, the document was sent for review to the Task Group members and further revised based on these comments.
Vegetation has been widely monitored in the vicinity of anthropogenic fluoride emission sources. The concentration of fluoride in bone varies with age, sex and the type and specific part of bone and is believed to reflect an individual’s long-term exposure to fluoride. However, cytogenetic damage in bone marrow or alterations in sperm cell morphology were reported when the substance was administered to rodents by intraperitoneal injection.
Airborne fluoride can also affect plant disease development, although the type and magnitude of the effects are dependent on the specific plant–pathogen combination. Therefore, care must be taken when interpreting the many field studies on fluoride pollution.
Other effects include lowered milk production and detrimental effects on the reproductive capacity of animals. Hydrogen fluoride may combine with water vapour to produce an aerosol or fog of aqueous hydrofluoric acid.
Unpublished data are used only when relevant published data are absent or when they are pivotal to the risk assessment. Correlations between fluoride concentrations in vegetation and annual growth increments, wind pattern, distance from fluoride source and hydrogen fluoride concentrations in aerial emissions have been observed.
Although adults may have a higher absolute daily intake of fluoride in milligrams, the daily intake of fluoride by children, expressed on a milligram per kilogram body weight basis, may exceed that of adults. The concentration of fluoride in dental enamel decreases exponentially with the distance from the surface and varies with site, surface attrition, systemic exposure and exposure to topically applied fluoride. These values give an atmospheric residence time of 12 h for gaseous fluoride and 50 h for particulates. In the dough for pies, breads, pancakes, and any other except for the ravioli, puff, custard, sand, it is recommended to add a handful or a tablespoon semolina on half a liter of fluid.
In its chemical properties glucose resembles an aldehyde and is a strong reducing agent, quickly precipitating gold and silver from warm solutions of their salts.
A detailed policy statement is available that describes the procedures used for unpublished proprietary data so that this information can be used in the evaluation without compromising its confidential nature (WHO (1999) Revised Guidelines for the Preparation of Environmental Health Criteria Monographs. The level of fluoride in foods is significantly affected by the fluoride content of the water used in preparation or processing, most notably in beverages and dry foodstuffs — for example, powdered baby formula — to which water is added prior to consumption.
Investigations of the effects of fluoride on wildlife have focused on impacts on the structural integrity of teeth and bone.
The concentrations of fluoride in unwashed or unprocessed foods grown in the vicinity of industrial sources (emissions) of fluoride may be greater than the levels in the same foods grown in other non-industrially exposed areas. Levels of fluoride in the urine of healthy individuals are related to the intake of fluoride.
In the vicinity of smelters, fluoride-induced effects, such as lameness, dental disfigurement and tooth damage, have been found. After that, proceed to their connection, this will require you selected beforehand filling.
The reaction between glucose and an alkaline solution of copper hydroxide (Fehling's solution), which results in the precipitation of cuprous oxide, is used to estimate glucose in aqueous solution. In commercially available infant formulas sold in the USA, soy-based ready-to-use and liquid concentrate formulas contained higher levels of fluoride than the equivalent milk-based products; however, no significant difference was observed between soy- and milk-based powdered infant formulas. Increased levels of urinary fluoride have been measured in individuals following occupational exposure to airborne fluoride and among those residing in areas associated with endemic fluorosis.
In the absence of other sugars, glucose may be estimated by observing the extent to which it rotates the plane of polarized light since a given weight of pure glucose has a fixed rotation.
OR half a glass of water to dissolve 1 tsp soda and repay it with citric acid or vinegar.4 . If you knead yeast dough, all products must be at room temperature, but not cold, because the cold slows rise test.6. In any dough better not add the melted butter, because melted butter significantly affects the structure of the test.11. All rich products, which include milk, much tastier, more fragrant and more crust shiny and beautiful.12.
If after 30 minutes the cracks do not appear, it means that the quality of the yeast is poor.13. Remember that an excess of sugar in the dough pies quickly "rosy" and burn, as well as slowing down the fermentation of yeast dough, and therefore are less lush cakes.



Normal blood glucose for diabetic cats diet
Pw 300
Diabetes natural sugar in fruit


Comments

  1. 13.05.2014 at 22:20:12


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    Author: Ugaday_kto_ya
  2. 13.05.2014 at 17:51:49


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    Author: Puma
  3. 13.05.2014 at 10:35:28


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  4. 13.05.2014 at 13:54:54


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    Author: FENERBAHCE
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    Author: ESCADA