Abstract
The present study examined the adverse effects of fluoride exposure on embryos and larvae of Rana chensinensis. Survival, morphological abnormalities, growth and development, time to metamorphosis and size at metamorphic climax of R. chensinensis were examined. Our results showed that embryos malformation occurred in all fluoride treatments. Morphological abnormalities of embryos are characterized by axial flexures, the extrusion of fin axis, edema, and ruffled dorsal and ventral fin. Additionally, 4.1mg F–/L and above could significantly inhibit embryos growth and development. On day 15, total length and weight of tadpole were significantly lower in 19.6 and 42.4mg F–/L treatments compared to control. However, significant reductions in total length and weight were observed only at 42.4mg F–/L on day 30. Moreover, significant metamorphic delay and decrease in the size at metamorphic climax were found in larvae exposed to 42.4mg F–/L. Taken together, embryos of R. chensinensis are more vulnerable to fluoride exposure than their tadpoles. Our results suggested that the presence of high concentrations fluoride might increase mortality risk and a reduction in juvenile recruitment in the field by increasing embryos malformation, delaying metamorphosis and decreasing size at metamorphosis.
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Fluoride toxicity in the male reproductive system
This review covers the current scientific understanding of the links between environmental exposure to fluoride (F) and its known or potential effects on human male fertility. The most important consequences of these F exposures are: changes in the structure and functional behavior of spermatozoa, disruption of spermatogenesis, and disturbances of
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Effect of fluoride on endocrine tissues and their secretory functions - review.
Highlights Fluoride induce e.g. oxidative stress, apoptosis and inflammation in endocrine tissues. Fluoride causes changes in the level of hormones released from endocrine tissues. Fluoride causes changes in the morphology of endocrine tissues. Abstract The effects of fluoride on endocrine tissues has not been sufficiently explored to date. The current body of
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Impact of subchronic exposure to triclosan and/or fluoride on estrogenic activity in immature female rats: The expression pattern of calbindin-D9k and estrogen receptor a genes.
This study explored the influence of triclosan (TCS) in the absence and presence of sodium fluoride (NaF) on estrogenic activity and thyroid function of adolescent female rats. The results indicated that the individual exposure to TCS evoked a significant decline in T3 and T4 but the levels of estradiol, FSH,
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Effect of sodium fluoride on the structure and function of the thyroid and ovary in albino rats (Rattus Norvegicus).
Objective: The objective was to investigate the effect of sodium fluoride (NaF) on the structure and function of the thyroid and ovary in albino rats. Method: Twenty-four female adult albino rats, 160–180 g body weight (bw), were divided into four groups of 6: the control group (I) received defluoridated water while the other
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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
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Fluoride Aggravates Thyroid Damage Caused by Excess Iodine Intake
Chinese researchers have found that the combination of excess fluoride with excess iodine caused greater reductions in IQ, or greater increases in goitre than either scenario by itself.
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The Relationship Between Fluoride Exposure & Goitre in South Africa
As a general rule simple goitre, irrespective of the cause, can be very, or fairly, satisfactorily combated by an adequate increase in man's daily iodine intake, except when the enlargement of the gland is due to the ingestion of excessive amounts of fluorine. The only correct solution to fluorine-induced endemic goitre is the removal of this element from the drinking water.
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Is fluoride-induced hyperthyroidism a cause of psychosis among East African immigrants to Scandinavia?
When people with a compensated fluoride-induced hypothyroidism move to a low-fluoride area, the fluoride-induced inhibition of the production of thyroid hormones ceases. In Scandinavia, the dietary intake of iodine is usually quite high due to iodized table salt and easy access to marine fish. Under these conditions, the elevated capacity for production of thyroid hormones may result in hyperthyroidism.
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Fluoride's Impact on Thyroid Hormones
Up through the 1950s, doctors in Europe and South America prescribed fluoride for this purpose in patients with hyperthyroidism. (Merck Index 1968). Fluoride was selected as a thyroid suppressant based on findings dating back to the mid-19th century that fluoride is a goitrogen (a substance that can cause goiter). When used as
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Fluoride's Effect on Male Reproductive System - Human Studies
Consistent with in vitro and animal research, studies of human populations have reported associations between fluoride exposure and damage to the male reproductive system. Most notably, a scientist at the Food & Drug Administration reported in 1994 that populations in the United States with more than 3 ppm fluoride in their water had lower "total fertility rates" than populations with lower fluoride levels.
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