Abstract
Maize seedlings of the genotype A1A2C1Wx were fumigated in growth chambers with hydrogen fluoride (HF) at a concentration of about 3 ug/m3. The experiment was run for 1O days, with the first group of treated plants removed from the chambers after 4 days and then at intervals of 2 days. Microsporocyte smears from the treated plants revealed chromosomal aberations that included asynaptic regions, translocations, inversions; and bridges plus fragments or fragments by themselves. It is believed that these abnormalities were due to the physiological effect of HF causing the chromosomes to become sticky and/or to the occurrence of chromatid breakage followed by reunion to form structural changes. These findings indicate that HF is a mutagenic agent.
-
-
Sister chromatid exchanges: a study in fluorotic individuals of North Gujurat
The purpose of this preliminary investigation was to compare the genotoxic effect of fluoride in human individuals directly exposed to high concentrations of drinking water fluoride (1.95 to 2.2 ppm) with those in individuals exposed to concentrations (0.6 to 1.0 ppm) within the WHO permissible limit. Sister chromatid exchanges (SCE)
-
Sodium fluoride and chromosome damage (in vitro human lymphocyte and in vivo micronucleus assays)
The clastogenic potential of sodium fluoride was determined both in vitro (using cultured human lymphocytes) and in vivo (using the rat bone-marrow micronucleus test). The incidence of chromosome aberrations in human lymphocyte cultures exposed to 20 or 40 micrograms/ml sodium fluoride (3 and 9% respectively) was significantly increased compared with
-
Long-term exposure to fluoride in drinking water and sister chromatid exchange frequency in human blood lymphocytes
The genetic toxicity of fluoride has been investigated extensively by various test systems. However, results obtained have been inconsistent. Fluoride has been reported to be non-genotoxic, genotoxic, and synergistic or antagonistic with certain mutagens. To date, there are no published human studies on the genotoxicity of fluoride. The purpose of
-
Sodium fluoride promotes morphological transformation of Syrian hamster embryo cells
Sequential treatment of Syrian hamster embryo (SHE) cells with a chemical carcinogen followed by sodium fluoride (NaF) resulted in a higher yield of morphologically transformed cell colonies than treatment of the cells with carcinogen alone. For example, cells treated with benzo[a]pyrene (B[a]P; 3 micrograms/ml) for 3 days, then with NaF
-
In vivo suppression by fluoride of chromosome aberrations induced by mitomycin-C in mouse bone marrow cells.
In vivo clastogenic effects of mitomycin-C (MMC) in bone marrow cells of four groups of young male Swiss albino mice exposed to 0, 7.5, 15, and 30 mg NaF/L in their drinking water for 30 days were investigated. The percentages of aberrant metaphases and chromosome aberrations in all F-treated mice
Related Studies :
-
-
-
NTP Bioassay on Fluoride/Cancer (1990)
In 1977, the U.S. Congress requested that animal studies be conducted to determine if fluoride can cause cancer. The result of the Congressional request was an extensive animal study conducted in the 1980s by the National Toxicology Program (NTP) and published in 1990. The main finding of NTP's study was a dose-dependent increase in osteosarcoma (bone cancer) among the fluoride-treated male rats.
-
A Critique of Gelberg's Study on Fluoride/Osteosarcoma in New York
The case-control study by Gelberg, published first as a PhD dissertation and then later in two peer-reviewed journals, may represent the most substantive study on fluoride/osteosarcoma previous to Bassin’s 2001 analysis. In assessing Gelberg’s data, we were at first struck by the existence of several notable errors in both the thesis and papers. While these errors do raise questions about the study, our primary concern with Gelberg’s work relates to the methods she used to analyze her data.
-
Fluoride/Osteosarcoma Link Is Biologically Plausible
The "biological plausiblility" of a fluoride-osteosarcoma link is widely acknowledged in the scientific literature. The biological plausibility centers around three facts: 1) Bone is the principal site of fluoride accumulation, particularly during the growth spurts of childhood; 2) Fluoride is a mutagen when present at sufficient concentrations, and 3) Fluoride can stimulate the proliferation of osteoblasts (bone-forming cells).
-
Fluoride's Mutagenicity: In vivo Studies
Consistent with dozens of in vitro studies, a number of in vivo studies, in both humans and animals, have found evidence of fluoride-induced genetic damage. In particular, research on humans exposed to high levels of fluoride have found increased levels of "sister chromatid exchange" (SCE). As noted in one study: "In
-
Fluoride's Mutagenicity: In vitro Studies
According to the National Toxicology Program, "the preponderance of evidence" from laboratory "in vitro" studies indicate that fluoride is a mutagenic compound. Many substances which are mutagens, are also carcinogens (i.e. they can cause cancer). As is typical for in vitro studies, the concentrations of fluoride that have generally been tested
Related FAN Content :
-