Cytological Effects of Hydrogen Fluoride on Tomato Chromosomes

Mohamed, Aly H.; Smith, Jason M.; Applegate, Howard G.

doi:10.1139/g66-069

Cited by 26 publications

(17 citation statements)

References 8 publications

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“…fluoride as sodium fluoride in drinking water. Mohamed & Chandler (1982) suggested that fluoride (Neelam et ai, 1987) led to an experimental study in rabbits. In the present study, the effects of fluoride on the rabbit male reproductive system were investigated, focusing on the structure of the testis, epididymis and vas deferens, using light and scanning electron microscopy.…”

Section: Introductionmentioning

confidence: 99%

A study of the effect of high concentrations of fluoride on the reproductive organs of male rabbits, using light and scanning electron microscopy

Susheela

Kumar²

1991

Reproduction

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Section: Introductionmentioning

confidence: 99%

A study of the effect of high concentrations of fluoride on the reproductive organs of male rabbits, using light and scanning electron microscopy

Susheela

Kumar²

1991

Reproduction

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“…Chromosome aberrations were induced in a dose-dependent manner in spermatocytes from BALB/c mice given drinking water with 0, 1, 5, 10, 50, 100 or 200 mg fluoride/L for 3-6 weeks in the highest exposed animals (Mohamed and Chandler, 1982). Swiss Webster mice, on the contrary, who received fluoride in drinking water (1-100 mg/L) for six months or were maintained for several generations on drinking water with 50 mg fluoride/L did not develop chromosomal aberrations in mitotic or meiotic cells of testes (Martin et al, 1979).…”

Section: In Vivo Studiesmentioning

confidence: 99%

Opinion of the Scientific Panel on Dietetic Products, Nutrition and Allergies (NDA) on a request from the Commission related to the Tolerable Upper Intake Level of Fluoride

Products¹

2005

EFSA Journal

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SUMMARYFluoride is not essential for human growth and development but is beneficial in the prevention of dental caries (tooth decay) when ingested in amounts of about 0.05 mg/kg body weight per day and when applied topically with dental products such as toothpaste. Dental enamel which contains fluoride is less likely to develop caries, because of greater resistance to ingested acids or to acids generated from ingested sugars by the oral bacteria. In addition, fluoride inhibits sugar metabolism by oral bacteria.Fluoride content of the body is not under physiological control. Absorbed fluoride is partly retained in bone and partly excreted, predominantly via the kidney. In infants retention in bone can be as high as 90% of the absorbed amount, whereas in adults retention is 50% or less. Fluoride is also incorporated into dental enamel during tooth formation.Excessive intake of fluoride during enamel maturation before tooth eruption from birth to eight years of age, when enamel formation is complete, can lead to reduced mineral content of enamel and to dental fluorosis of deciduous but predominantly of permanent teeth. The incidence and severity of dental fluorosis is dose-dependent. Mild dental fluorosis is not readily apparent and is associated with increased resistance to caries. The Panel considered moderate dental fluorosis, which is characterised by staining and minute pitting of teeth, to be an adverse effect. On the basis that the prevalence of moderate dental fluorosis of permanent teeth is less than 5% in populations ingesting 0.08-0.12 mg fluoride/kg body weight/day, the Panel considered that the upper level (UL) for fluoride is 0.1 mg fluoride/kg/day in children aged 1-8 years. This is equivalent to 1.5 and 2.5 mg fluoride per day in children aged 1-3 years and 4-8 years, respectively.Fluoride accretion in bone increases bone density but excessive long term intake reduces bone strength and increases risk of fracture and skeletal fluorosis (stiffness of joints, skeletal deformities). Studies with therapeutic oral administration of fluoride in amounts of 0.6 mg/kg body weight/day in postmenopausal women over several years increased the risk for nonvertebral bone fractures significantly. The Panel applied an uncertainty factor of 5 to derive an UL of 0.12 mg/kg body weight/day. This is equivalent to an UL of 5 mg/day in children aged 9-14 years and 7 mg/day for age 15 years and older, including pregnant and lactating women.The UL for fluoride applies to intake from water, beverages, foodstuffs, including fluoridated salt, dental health products and fluoride tablets for caries prevention.Children aged 1-8 years have fluoride intakes from food and water well below the UL provided the fluoride content of their drinking water is not higher than 1.0 mg/L. An increase

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“…Sources of HF emissions, foliar injury symptoms induced by HF, relative susceptibilities of plant species to foliar injury, effects on physiological processes and crop quality have been well documented. 1 " 4 In addition to these effects, Mohamed and his co-workers have reported that HF induced cytogenetic changes in tomato plants, 5 …”

mentioning

confidence: 99%

“…Mohamed 6 had reported observing several chromosomal aberrations in progeny of tomatoes fumigated with HF; these abnormalities were similar to those reported in tomato plants fumigated directly with HF. 5 Experiments using onion (Allium cepa L.) root-tips exposed to high concentrations of fluoride in aqueous solution produced different results. After immersion for 24 hr in 10~2M NaF or 10~2M NaCl, the number of aberrations observed in metaphase chromosomes was greater in samples exposed to NaF than NaCl (Table II).…”

mentioning

confidence: 99%