DEFLUORIDATION

DEFLUORIDATIO N & AN UPDATE ONIndex 1 Introduction Methods available for defluoridation 2 - changing the water supply - ion exchange process - addition of chemicals 3 4 5 6 7 8 9 10 Practical experience of defluoridation Nalgonda technique Update on fluorosis Overall prevalence in India Overall prevalence in TamilNadu Antifluoridation Fluoride Bomb Conclusion 6 8 12 13 14 16 18 23 3 2 2 Knowledge that excess level of fluoride in drinking water is related to the occurrence of dental fluorosis precedes the unravelling of the fluoride and caries relationship. Govt. of India have prescribed 1mg/l and 2mg/l as the permissive and excessive limits respectively. High fluoride levels of more than 4 PPM are found in Punjab. (Indian Standard Institute. which depend on the annual. Andhra Pradesh.2mg/l.2 million people lived in 1142 communities served by public health water supplies that exceeded the upper control limit for fluoride content. Gujarat. 3 . The US Public Health Services (1962) Drinking Water Standards list ‘optimum fluoride concentration’ and ‘upper control limits’. US Public Health Services estimated that about 4. The Indian Standard Specification for drinking water gives a desirable limit of 0. fluoride concentration exceeds 21 mgF/l. High levels of dental fluorosis are disfiguring and constitute a public health problem such that drinking water facilities in some countries include upper limits for fluoride concentration.6 – 1. 1983). mean maximum daily temperature. Haryana. Madhya Pradesh. Rajasthan. TamilNadu. The Ministry of Health. It was estimated in 1980 that 2240 villages or communities with a population of nearly 2 million appeared to be exposed to high fluoride levels that may require defluoridation. At that time. Many states in India have ground waters between 1 and 5 mg F/l and in some areas.INTRODUCTION Dental caries decreases but dental fluorosis increases as the concentration of fluoride in drinking water increases. activated alumina .activated carbon . METHODS AVAILABLE FOR DEFLUORIDATION: Changing the water supply Based upon ion exchange process or adsorption Based on addition of chemicals to water during treatment Based upon ion exchange process or adsorption: Materials used in contact beds are: .’ The most obvious way of reducing exposure to water borne fluorides is to change the water supply to one containing an acceptable level of fluoride.magnesia . Most other methods involve chemical or physiochemical removal of fluoride. These have been reviewed by Moller (1988) and with specific reference to India by Tewari and Goyal (1986). 4 .natural or synthetic tricalcium phosphate .hydroxy apatite .Water defluoridation is defined as ‘the downward adjustment of fluoride ion concentration in a public water supply so that the level of fluoride is maintained at the normal physiological level of 1 PPM to prevent dental caries with minimum possibility of causing dental fluorosis.processed bone .ion exchangers Processed bone: Dried and crushed natural bone and bone char (dried and crushed bone heated to 6000C for 20 mins) are efficient removers of fluoride. Hydroxyapatite: The affinity of fluoride for hydroxyapatite is an important reason for fluoride anticaries effect and is used as a method for defluoridation. Secondly. Activated alumina: Mainly aluminium oxide – investigated in the USA (Horowitz. Other methods such as reverse osmosis and electrolysis. Both lime and aluminium have disadvantages. It is most effective when pH is low. coconut fibre and other carboniferous waste. Activated carbon: This is produced from heated and ground wood. 1964) and India (Bulusu and Nawlakhe. Lime and aluminium: Lime and aluminium sulphate both have a high affinity for fluoride and can be used for removal of excess fluoride from water either alone or in combination. but this is disadvantageous as the pH of the water then has been raised to make it acceptable for consumption. A 3:1 mixture of bone char and charcoal has been used in Thailand and may be especially useful for household units. control of pH and alkalinity is crucial when lime is used. and the method is only reasonable when removal of both hardness and fluoride is required.Later is preferred since bacterial contamination is reduced and taste is improved compared with natural bone. dosage with aluminium has to 5 . 1988). First. although effective are too expensive to consider further. Maier and Thompson. paddy husks. Bone char can be regenerated with caustic soda. It should be noted that the use of bone is unacceptable in some religious groups. Powdered hydroxyapatite is effective alone or in combination with tricalcium phosphate. Magnesium oxide has been used as an alternative to calcium oxide. but reaction time was faster with bone meal than with magnesium oxide. and the taste of the water treated with bone meal was also better. and aluminium chloride is sometimes used together with aluminium sulphate. Moller. A number of these resins have been proposed.be carefully controlled so as to allow excess levels of residual aluminium. of those investigated are: Polystrene resins Strongly basic quarternary ammonium type resins Sulphonated saw dust impregnated with aluminium Defluoron 1 Defluoron 2 Ion exchange resins: 6 . MgO and bone meal are readily available and inexpensive in Kenya. 1988) Egs. Both removed fluoride. The combined use of lime and aluminium is the central feature of the Nalgonda Technique which was developed at the Indian NEERI at Nagpur in 1974. 1986. (Tewari and Goyal. Taste of the treated water is sometimes poor. Ion exchange resins: These are commercially produced resins and are expensive and uneconomical in most circumstances. Opinaya. It was developed for medium size communities but is adaptable down to village level. Pameiyer and Gron(1987) investigated the possibilities of using magnesium oxide or bone meal to defluoridate Kenyan drinking water. where water fluoride levels exceed 9ppm. Can be used on sodium and hydrogen cycles .use of lime either alone or with magnesium salts . Idaho. Mckay and Elove (1938) reported a reduction in the mottled enamel in children. Mckay (1933) reported a dramatic reduction in the prevalence of brown stained teeth. Sulphonated coal and works on Al cycles Based upon addition of chemicals to water during treatment: Chemical treatment methods include: . USA in 1925. Deacodite FF(1 P) and Lawatit MIH – 59.Anion exchange resins: Polysterene ion exchange resins in general and strongly basic quaternary ammonium type resin in particular Tulsion A-27. 5 years later. 10 years after the water supply of the town of Bauxite. similar results were noted in South Dakota. Cation exchange resins: .Carbion – good durability.Defluoron 1 – sulphonated saw dust impregnated with 2% alum solution .Magnesia – removes excess F (Ph of water is 10 or more – acidification or recarbonation necessary) . Partial replacement was described by Gerrie and Kehr (1957) where dental fluorosis was prevented by children using low fluoride bottled water. 7 . Dean. However.aluminium salts either alone or in combination with a coagulant air PRACTICAL EXPERIENCE IN DEFLUORIDATION: CHANGE IN WATER SUPPLY: When a new pipeline was established from Carpenter Springs to the village of Oakley. replacement or dilution of a community water supply is not always practical or feasible.Defluoron 2 .1968. Arkansas was changed and one year later. A pilot plant using anion exchange resins (carbion and defluoron::8:1) commenced at Gangapur. Over a period of 16 years. This used activated alumina in an insoluble granular form and reduced the fluoride level from 8ppm to 1 ppm. Defluoridation plant was installed by the USPHS. Barlett. India: India has extensive areas of endemic fluorosis.5ppm and later to 1. defluoron 2 was developed in 1968. South Dakota. it reduced the fluoride level to 2. USA a defluoridation plant using synthetic hydroxyapatite became operational. Rajasthan. Defluoron 2 – sulphonated coal using aluminium solution as regenerant. USA: In South Dakota. but the solution was unsuccessful as most of the defluoron 1 was washed out. Prevalence of fluorosis in Barlett children fell from 96% in 1954 to 18% in 1964. To overcome these problems. When bone char was used. which reduced the fluoride ion concentration to 3-6ppm only. Hence. the level of fluorosis fell from 100% to 29% of the children being affected. it was closed 4 years later. Aluminium solution was used as the regenerant.6ppm. Life of the medium – 2 to 4 years 8 . Texas. USA: The fluoride level in water was 8ppm in USA.Britton. It has a population of 3. NALGONDA TECHNIQUE: NEERI – National Environmental Engineering Research Institute Process for removal of excess fluoride in ground water by using Nalgonda Technique By this method. NEERI developed the Nalgonda technique. For community level.5 mg/l for domestic and community use can be supplied. Raw materials: High fluoridated raw water 9 . Nalgonda District is a district in Andhra Pradesh. lime and bleaching powder to the raw water followed by flocculation. Black Hills. The domestic level treatment is performed in a bucket or any plastic container. fill and draw type plants are used with capacity upto 400ml/day. In response to this drawback.e.247.32% is urban as of 2001. Salient features of process/technology: Excess fluoride in drinking water causes skeletal and dental fluorosis. but regeneration and maintenance of the plant required skilled operator which was not readily available. The process comprises addition of aluminum salts.Tewari and Goyal (1986) reported that defluoron 2 was successful in removing fluorides. sedimentation and filtration. safe drinking water with fluoride content within permissible limits of 1.982 of which 13. This water can be purified at domestic and community levels. Its name is derived from two telugu words Nalla (Black) & Konda (Hills) i. Flocculated water – settle and filter through fullers earth candles overnight. flocculator. Community Level Defluoridation: Equipment and machinery required are setting tank.Alum Lime Bleaching powder Domestic defluoridation filters: Stainless steel candle filters adopting Nalgonda technique. rapid gravity sand filter and disinfection unit. Equipment – water filter of any size and make. Treated water – 6AM – 1PPM F or less Filter washed daily before next filling. Mechanism Of Defluoridation: Rapid mix Flocculation Sedimentation Filtration Operation and maintenance: Operated and maintained by individual household 22 l of fluoridated water = 20 l of defluoridated water 22l of test water – upper chamber – add reqd. flash mix and pump. fitted with candle filters and additional mixing device which can be used as domestic defluoridation filters. 10 . – 2 to 4 rpm. dose of aluminium salt solution Mix rapidly – 30 to 60 secs – 10 to 20rpm – coagulant – rapidly and uniformly dispersed – tiny flocs formed Slow mixing –10 to 15 mins. alternate low fluoride source within transportable distance Total dissolved solids are below 1500mg/l. 35.5 to 20 mgF/l to desirable levels.6 lacs – 250 population Requires skilled operator and chemicals 50 SS filters – Rs. 1. desalination may be necessary when the total dissolved solids exceed 1500mg/l Raw water fluoride ranging from 1. operation and maintenance Highly efficient removal of fluoride from 1.5mgF to 20mgF/l.Package pump installed on hand pump schemes costing Rs. Cost effectiveness: 11 .000 Advantages: Low cost of investment Low cost of maintenance Salient features: No regeneration of media No handling of caustic acids and alkalies Only requires readily available chemicals used in conventional municipal water treatment Adaptable to domestic use Simplicity of design. construction. Little wastage of water and least disposal problem Needs minimum of mechanical and electrical equipment No energy except muscle energy for domestic equipment Indications for adopting nalgonda technique: Absence of acceptable. 1988) A defluoridation plant using Nalgonda technique was commissioned in the town of Kadiri. but it is likely to much cheaper than transporting water over long distances. UPDATE ON FLUOROSIS: 12 . Subsequently.1 to 4. During the first few years. 5 lakhs The cost of water defluoridated using the Nalgonda technique is about 1.Minimum economic unit size: 1. (Bulusu. visitors reported that the operation and maintenance of the plant declined and this was confirmed by NEERI during two visits in 1984-86.5 to 3 times the cost of the untreated water.8 mgF/l. Community level: Capacity – 400 l Cost – Rs. Andhra Pradesh in 1980 to treat water containing 4. Domestic level: Capacity – 25l/batch Cost – Rs. The cost of treatment was calculated at 1rupee/m3. These difficulties highlight the problem of maintenance and staffing. the plant became a model of water treatment technology for defluoridation. 400 2. Maharashtra and UP 13 . Fluoride level in drinking water – 1. these age groups assume the greatest importance for assessment of fluorosis status in the country.5ppm or more. Pondicherry and none in Chandigarh . The Dean’s index has been used in this study to record fluorosis status. Since these teeth would have erupted at 12 and 15 years of age. Karnataka.40-50% of households – Gujarat.The National Oral Health Survey and Fluoride Mapping of the Dental Council of India is the first ever national level epidemiological survey in the country. Amount of water consumed and age when it is consumed are important factors which influence fluorosis. Fluorosis most frequently affects premolars and second molars. About 27% of the house holds in India use water with fluoride levels of 1. which was initiated in 2002.Few households in Delhi. The scope of the survey was to collect information covering the following dimensions of oral health: Prevalence of oral health problems Fluoride levels in drinking water Eating habits affecting oral health Dental cleaning practices Awareness and knowledge of people on factors affecting oral health Treatment seeking behaviour of people for their oral health problems Dental fluorosis results from drinking water drawn from ground water sources containing a high fluoride content (more than 2ppm) over the period when teeth are in the process of development or mineralisation.5ppm or more . Goa.6 to 2.9% 6% (questionable cases were excluded) Moderate form – 0.8% Moderate and severe form – even rarer 12 years and 15 years: Overall: 10..2% and 9. Kerala.2% Very mild and mild – 2% No marked gender related differentials Very mild and mild – occurred both in urban and rural areas (rural>urban) Rural areas – accounted for all of the ‘moderate’ fluorosis – 0.1% 14 .2% (questionable cases were excluded) Severe form – absent Moderate fluorosis – 0. TamilNadu & Haryana .One quarter of households in Jammu & Kashmir. Many states – 0.2% Fluorosis – negligible or virtually absent Assam.8% Severe form – 0. Pondicherry. Jammu & Kashmir and TamilNadu.About 10 or below % of households in remaining states and union territories OVERALL PREVALENCE IN INDIA: YOUNG CHILDREN (5 years): Overall – 5% 2. Action needs to be taken to provide preventive measures and safe drinking water EPIDEMIOLOGICAL STUDIES: 15 . The north region seems to have much higher levels of fluoride in water than other regions – almost two thirds of the households had fluoride levels of more than 1.1% in 12 & 15 year old children. AP – 12 year old children.2% & 2. fluorosis – very low prevalence in the country ‘Moderate’ and ‘severe’ fluorosis .4% (exclusion of the questionable fluorosis) No gender differences Marginally more in rural areas Haryana and Gujarat – above average prevalence of fluorosis.No gender differences Rural subjects – marginally higher prevalence Haryana.5ppm or more.5ppm. Rural areas are very highly affected compared to urban areas.<1% ‘Very mild’ & ‘mild’ – not more than 5. Endemic fluorosis – some pockets in some states – localised and small PREVALENCE OF FLUOROSIS IN TAMILNADU: About 1/4ths of households in TamilNadu use drinking water with fluoride levels of 1. This percentage is much higher in rural areas. This is cause of alarm. Overall. 16% of the children are affected and mostly of the mild variety.‘severe’ fluorosis – higher than the national average 35 – 44 & 65 – 74 years: 4. UP. 89% . where the fluoride levels of water was 0.skeletal fluorosis Serum levels of the children showed elevated levels of alkaline phosphatase.dental fluorosis 39% . aspartate phosphatase and decreased levels of total protein. Bardsen A (1999) did a systematic review to find out the ‘risk periods’ associated with the development of dental fluorosis in maxillary permanent central incisors. et al (2005) did a study to compare the occlusal disharmonies among 332 preschool children in a high fluoride area with those of 332 children in a low fluoride area of Turkey. He said that ‘no specific period of enamel formation is singled out as the being the most critical for the development of dental fluorosis. rather than specific risk periods. The duration of fluoride exposure during the amelogenesis. anterior cross bite was significantly higher whereas anterior openbite and anterior crowding were significantly lower compared with those of the low fluoride area.6– 13. Saglam AMS.Shivasankara AR. Karnataka. Results showed that in a high fluoride area. alanine phosphatase.4ppm. Shivaraja SYM. Hanumanth RS. albumin and potassium. ANTIFLUORIDATION: 16 . Kirzloghu Z. et al (2000) – studied the prevalence of skeletal and dental fluorosis among children of Kheru Thanda of Gulbarga. would seem to explain the development of dental fluorosis in the permanent maxillary central incisor. No significant gender differences were found. Simsek S. Despite the immutable evidence supporting water fluoridation. Many reasons can be found to do away with fluoridation. but those organizations and individuals opposed raise concerns that the intake is not 17 . Opposition to water fluoridation refers to activism against the fluoridation of public water supplies. as Continental Europe does not practice water fluoridation. If you still like Fluoride. At the recommended concentration of 0. and the elderly can be placed in the group most likely to have adverse health effects from fluoridation. its universal implementation has been vehemently opposed by anti-fluoridationists. although some continental countries fluoridate salt.7 for hot climate. adding fluoride to public water supplies has been fiercely debated. hydrofluorosalicic acid is the only one added for medical reasons.2 in cool climates) the only apparent side-effect appears to be dental fluorosis. then rest assured you can get all that you need from Crest or Colgate.2 mg/L (0. Since 1945. Fluoride is a poison. young children. and is rated between Lead and Arsenic on the international toxcicity chart. without citizens being properly informed. To this day communities have fluoridation pushed onto them. Fluoride is not added to the water to make it safe.7 – 1. The controversy occurs mainly in English-speaking countries. Expecting mothers. Sodium Fluoride was not added to toothpaste until around the time water fluoridation became commonplace. it is added for medical purposes. Of all the chemicals mixed with water to make it safe. Water fluoridation is perhaps the only public health intervention where implementation is decided by the popular vote and the outcome is usually unfavorable. 1. Fluoride cannot be boiled out. It is harmful to health and a violation of human rights” says Daniela D-Ronberg.is not effective enough to justify the costs. Bristolians Against Fluoridation are trying to stop the fluoridation of the Bristol public water supply. .may cause serious health problems.imposes ethical issues. and others may be more susceptible to health problems. Opposition to fluoridation has existed since its initiation in the 1940s. while critics of this position have argued that this rests on an uncritical attitude toward scientific knowledge. Sociologists have typically viewed opposition to water fluoridation as irrational. small individuals. according to many scientific studies. 18 . . “Fluoridation has got to stop. spokesperson for the newly-formed Kapiti Fluoridation-free Campaign “I am particularly worried that we are still allowing this when the American Health Authorities are advising that babies are getting too much fluoride through the normal tap water when making up baby formula. can cause some serious debilitating adverse effects to human health. some opponents of water fluoridation also put forward conspiracy theories describing fluoridation as a communist plot to undermine public health. During the 1950s and 1960s.” Studies in New Zealand that looked at dental fluorosis (the first outward sign of fluoride poisoning) showed that 30% of children in fluoridated areas had some form of dental fluorosis as compared with only 15% in non-fluoridated areas. Those opposed also argue that water fluoridation . and that children. Fluoride is an accumulative poison that.easily controlled. public health leaders have maintained that low doses of fluoride are safe for people. declassified government documents are shedding new light on the roots of that still controversial public health measure. IDOF said. unethical and unsafe'. two thirds of U. "Most dentists would refuse to prescribe for a patient he/she has never met. Since the days of World War II. what it claims is. In addition. public drinking water is fluoridated. and good for children’s teeth. Today.S. This is the water fluoridation ethos". a substance which is intended to create bodily change for the rest of their life. disbelieving the government’s assurances of safety . Many municipalities still resist the practice. fluoridation is 'undemocratic. U. FLUORIDE BOMB: Some fifty years after the United States began adding fluoride to public water supplies to reduce cavities in children’s teeth. revealing a surprising connection between fluoride and the dawning of the nuclear age. That safety verdict should now be re-examined in the light of hundreds of once-secret 19 . the group intends to provide an education database of the current scientific literature showing.S. when this nation prevailed by building the world’s first atomic bomb. According to the group. whose medical history he/she does not know. the ‘health and dental damage caused by fluoride/fluoridation’.Dentists begin anti-fluoridation campaign??? Irish Dentists Opposing Fluoridation (IDOF) is a support group for dental professionals who wish to express their opposition to the addition of fluoride to drinking water. " they secretly gathered and analysed blood and tissue samples from Newburgh citizens. A-bomb program were not over radiation. the U. according to the documents. fluoride rapidly emerged as the leading chemical health hazard of the U. Atomic Energy Commission (AEC) -. Then. atomic bomb program— both for workers and for nearby communities.S. One of the most toxic chemicals known. The first lawsuits against the U. Human studies were required. the documents reveal. study of the health effects of fluoridating public drinking water—conducted in Newburgh. with the cooperation of State Health Department personnel. Bomb program researchers played a leading role in the design and implementation of the most extensive U. 20 . New York from 1945 to 1956.considered the most powerful of Cold War agencies—for reasons of national security. in a classified operation code-named "Program F.World War II documents obtained by Griffiths and Bryson—including declassified papers of the Manhattan Project. but over fluoride damage. who had been secretly ordered to provide "evidence useful in litigation" against defense contractors for fluoride injury to citizens.S. Massive quantities of fluoride—millions of tons—were essential for the manufacture of bomb-grade uranium and plutonium for nuclear weapons throughout the Cold War.S.S. The original secret version—obtained by these reporters—of a 1948 study published by Program F scientists in the Journal of the American Dental Association shows that evidence of adverse health effects from fluoride was censored by the U. Other revelations include: Much of the original proof that fluoride is safe for humans in low doses was generated by A-bomb program scientists. the documents show. Fluoride was the key chemical in atomic bomb production. military group that built the atomic bomb.S. according to the U. the first visible sign of excessive fluoride exposure.The bomb program’s fluoride safety studies were conducted at the University of Rochester. Large numbers of U. or journalists. but to environmental pollution by major industries from aluminum to pesticides: Fluoride is a critical industrial chemical. Professor of Chemistry at St. The declassified documents resonate with a growing body of scientific evidence. government’s conflict of interest—and its motive to prove fluoride "safe"—has not until now been made clear to the general public in the furious debate over water fluoridation since the 1950’s.Y. pediatric bone specialists have expressed alarm about an increase in stress fractures among U. The impact can be seen. (The signs are whitish flecks or spots. Human exposure to fluoride has mushroomed since World War II.S. Connett and other scientists are concerned that fluoride 21 . The fluoride studies were conducted with the same ethical mind-set. in which "national security" was paramount." explains Paul Connett. literally.S. or dark spots or stripes in more severe cases.S. nor to civilian researchers and health professionals. due not only to fluoridated water and toothpaste. young people—up to 80 percent in some cities—now have dental fluorosis. site of one of the most notorious human radiation experiments of the Cold War. National Research Council. and a chorus of questions. young people.S. The U. In recent years.) University. about the health effects of fluoride in the environment. in the smiles of our children. particularly on the front teeth. in which unsuspecting hospital patients were injected with toxic doses of radioactive plutonium. Lawrence (N.) Less-known to the public is that fluoride also accumulates in bones —"The teeth are windows to what’s happening in the bones. she says.Q. It seems most likely that the F [code for fluoride] component rather than the T [code for uranium] is the causative factor. Col. 1944 Manhattan Project memo reports: "Clinical evidence suggests that uranium hexafluoride may have a rather marked central nervous system effect. (New epidemiological evidence from China adds support.S. studies of fluoride’s effects on the human brain. even at low doses. Phyllis Mullenix. An April 29. in a reputable peer-reviewed scientific journal. showing a correlation between low-dose fluoride exposure and diminished I. flatly told her that "fluoride does not have central nervous system effects. her application for a grant to continue her CNS research was turned down by the U." The memo—stamped "secret"—is addressed to the head of the Manhattan Project’s Medical Section." Declassified documents of the U. Information was buried." concludes Dr. National Institutes of Health (NIH). Colonel Warren is asked to 22 . where an NIH panel. and now a critic of fluoridation..S. During her investigation.—linked to bone damage by studies since the 1930’s -. Then.S.) Mullenix’s results were published in 1995. bomb program scientists. Mullenix was astonished to discover there had been virtually no previous U.may be a contributing factor. former head of toxicology at Forsyth Dental Center in Boston. and might adversely affect human brain functioning.. researchers who have reviewed these declassified documents fear that Cold War national security considerations may have prevented objective scientific evaluation of vital public health questions concerning fluoride.S. according to this investigation. atomic-bomb program indicate otherwise. Stafford Warren. in children. Now. The declassified documents add urgency: Much of the original proof that low-dose fluoride is safe for children’s bones came from U.. Animal studies Mullenix and co-workers conducted at Forsyth in the early 1990’s indicated that fluoride was a powerful central nervous system (CNS) toxin. " On the same day. The proposal. Colonel Warren approved the CNS research program. at the time chief of fluoride toxicology studies for the University of Rochester division of the Manhattan Project. at the height of the Second World War and the nation’s race to build the world’s first atomic bomb." She went on. it’s probably still classified. Similarly. This is important not only to protect a given individual. however." said Charles Reeves. but the document they refer to is missing.. National Archives. the supporting evidence set forth in the proposal forwarded along with the memo must have been persuasive..approve a program of animal research on CNS effects: "Since work with these compounds is essential. For research on fluoride’s CNS effects to be approved at such a momentous time. After reviewing the memos. "If you find the memos. "How could I be told by NIH that fluoride has no central nervous system effects when these documents were sitting there all the time?" She reasons that the Manhattan Project did do fluoride CNS studies—"that kind of warning. but also to prevent a confused workman from injuring others by improperly performing his duties. Nearly fifty years later at the Forsyth 23 . is missing from the files of the U. chief librarian at the Atlanta branch of the U. that fluoride workers might be a danger to the bomb program by improperly performing their duties—I can’t imagine that would be ignored—but that the results were buried because they might create a difficult legal and public relations problem for the government. no results of the Manhattan Project’s fluoride CNS research could be found in the files. it will be necessary to know in advance what mental effects may occur after exposure. where the memos were found.S. National Archives and Records Administration. Mullenix declared herself "flabbergasted.S. Harold C. Hodge. This was in 1944." The author of the 1944 CNS research proposal was Dr. particularly where there is a risk of severe dental fluorosis. Second Edition." The "black hole" in fluoride CNS research since the days of the Manhattan Project is unacceptable to Mullenix. "There is so much fluoride exposure now. an NIH scientific review advisor familiar with Dr. He terms her claim of institutional bias against fluoride CNS research "farfetched. and we simply do not know what it is doing. "he never once mentioned the CNS work he had done for the Manhattan Project. who refuses to abandon the issue. Mullenix’s grant request. By then Hodge had achieved status emeritus as a world authority on fluoride safety. should maintain maximum fluoride level of 1." He adds. Fluorides and dental caries Murray J J. although this objective is admittedly not always technically easy to achieve." CONCLUSION: It has been suggested that countries with excessive levels of fluoride ingestion. Antonio Noronha." she says.5mg/l as recommended by WHO water quality guidelines. Dr. says her proposal was rejected by a scientific peerreview group." says Mullenix.Dental Center in Boston. "We strive very hard at NIH to make sure politics does not enter the picture.The Prevention of Dental Disease. Mullenix was introduced to a gently ambling elderly man brought in to serve as a consultant on her CNS research Harold C. REFERENCES: Amrit Tewari." Dr. Hodge. "But even though he was supposed to be helping me. Oxford University Press 24 . "You can’t just walk away from this. Fluoride and the Atom Bomb related?????? By kaylaosteen3 . First Edition. 38(1): 57-64. 2004. Fluorides in Dentistry. Essentials of Preventive and Community Dentistry. Third Edition. New Delhi. ‘Risk periods associated with the development of dental fluorosis in maxillary permanent central incisors: a meta analysis.html?id=3129 25 . Fluoride. Karnataka. National oral health survey and fluoride mapping. Simsek S. Kirzloghu Z. Dental Council of India. Bardsen A. 57: 247-256 Shivasankara AR.irishhealth. and the Atomic Bomb by Joel Griffiths and Chris Bryson © July 1997 National oral health survey and fluoride mapping. Brian B. Acta Odonto Scand 1999. 33(2): 66-73.com/article. India. Shivaraja SYM. Hanumanth RS. et al. Ekstrand J. Teeth. New Delhi. Dental Council of India.Fejerskov O. Reed Elsevier India Private Limited. Textbook of Preventive and Community Dentistry. et al. Arya Publishing House. Munksgaard Publishers. A clinical and biochemical study of chronic fluoride toxicity in children of Kheru Thanda of Gulburga District.myspace. Hiremath S S. Tamil Nadu. Second Edition. Occusal disharmonies of primary dentition in a high and low fluoride area of Turkey. Soben Peter.Posted on May 11th. http://www.com/cheathamaware http://www. 2004.Burt. 2002 –2003. Saglam AMS. 2006. Fluoride 2005. Fluoride 2000. India. 2002 –2003. http://en.wikipedia.org/wiki/Opposition_to_water_fluoridation 26 .