- Responses in NaF-exposed freshwater snail, Bellamya bengalensis was estimated.
- Mortality increased with elevated fluoride concentrations and increasing exposure period.
- Altered behavior and lowered oxygen consumption were concentration-dependent.
- Decreased haemocyte count could impact respiratory capacity.
- Reduced protein content in hepatopancreas indicate impaired protein synthesis.
There is limited information on fluoride toxicity and risk overview on ecotoxicological risks to aquatic invertebrate populations particularly molluscan taxa. This necessitated the assessment of toxicity responses in the freshwater snail, Bellamya bengalensis exposed to environmentally relevant concentrations of sodium fluoride. Under lethal exposures (150, 200, 250, 300, 400 and 450 mg/l), the median lethal concentrations (LC50) were determined to be 422.36, 347.10, 333.33 and 273.24 mg/l for B. bengalensis at 24, 48, 72 and 96 h respectively. The rate of mortality of the snails was increased significantly with elevated concentrations of the toxicant. The magnitude of toxicity i.e., toxicity factor at different time scale was also higher with increased exposure duration. Altered behavioural changes i.e., crawling movement, tentacle movement, clumping tendency, touch reflex and mucous secretion in exposed snail with elevated concentrations and exposure duration. Similarly, oxygen consumption rate of the treated snail also lowered significantly during 72 and 96 h of exposure. Under 30-day chronic exposures (Control-0.00 mg/L; T1–27.324 mg/L; T2–54.648 mg/L), protein concentrations in gonad and hepatopancreas of exposure groups was significantly lowered. Chronic exposures also revealed lowered haemocytes counts in exposure groups. The potential for loss of coordination, respiratory distress and physiological disruption in organisms exposed to environmentally relevant concentrations of fluoride was demonstrated by this study. The estimation and magnitude of toxicity responses are necessary for a more accurate estimation of ecological risks to molluscan taxa and invertebrate populations under acute and chronic fluoride exposures in the wild.
Fluoride in Drinking Water: A Scientific Review of EPA’s Standards.
Excerpts: Summary Under the Safe Drinking Water Act, the U.S. Environmental Protection Agency (EPA) is required to establish exposure standards for contaminants in public drinking-water systems that might cause any adverse effects on human health. These standards include the maximum contaminant level goal (MCLG), the maximum contaminant level (MCL), and the secondary
Lipid peroxidation in fluorosis and the protective role of dietary factors
The influence of chronic Fl intoxication on lipid peroxidation and the state of the antioxidant system was studied in rats on different diets. Chronic Fl intoxication inhibited antioxidant activity and caused an increase in the rate of peroxidation and the level of lipoperoxides in liver, brain and serum. Diets with
Pathological changes in the tissues of rats (albino) and monkeys (macaca radiata) in fluorine toxicosis
1. Stomach, duodenum, small intestine, kidney, liver, spleen, skin, heart, aorta, lungs, brain, pancreas, adrenals, thyroid and parathyroid of rats and monkeys suffering from chronic fluorosis have been histologically examined. 2. Fluorine has not been found to have any effect on the heart muscle, aorta, skin and parathyroids, whereas it has
Fluoride distribution in rats during and after continuous infusion of Na18F.
Rats were given Na18F as a radiotracer for F- at varying chemical dose rates by continuous i.v. infusion for 3 h. Blood fluoride was assessed 6-7 times over the infusion period, at the end of which the animals were sacrificed for determination of tissue fluoride distribution. At sublethal dosages, the
Environmental Fluoride 1977 by Rose & Marier
The Associate Committee on Scientific Criteria for Environmental Quality was established by the National Research Council of Canada in response to a mandate provided by the Federal Government to develop scientific guidelines for defining the quality of the environment. The concern of the NRC Associate Committee is strictly with scientific
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NRC (2006): Fluoride's Neurotoxicity and Neurobehavioral Effects
The NRC's analysis on fluoride and the brain.
Fluoride: Developmental Neurotoxicity.
Developmental Neurotoxicity There has been a tremendous amount of research done on the association of exposure to fluoride with developmental neurotoxicity. There are over 60 studies reporting reduced IQ in children and several on the impaired learning/memory in animals. And there are studies which link fluoride to Attention Deficit Hyperactivity Disorder. Teaching
Fluoride's Direct Effects on Brain: Animal Studies
The possibility that fluoride ingestion may impair intelligence and other indices of neurological function is supported by a vast body of animal research, including over 40 studies that have investigated fluoride's effects on brain quality in animals. As discussed by the National Research Council, the studies have consistently demonstrated that fluoride, at widely varying concentrations, is toxic to the brain.
Fluoride's Effect on Fetal Brain
The human placenta does not prevent the passage of fluoride from a pregnant mother's bloodstream to the fetus. As a result, a fetus can be harmed by fluoride ingested pregnancy. Based on research from China, the fetal brain is one of the organs susceptible to fluoride poisoning. As highlighted by the excerpts
Fluoride Affects Learning & Memory in Animals
An association between elevated fluoride exposure and reduced intelligence has now been observed in 65 IQ studies. Although a link between fluoride and intelligence might initially seem surprising or random, it is actually consistent with a large body of animal research. This animal research includes the following 45 studies (out
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