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Water fluoridation—no evidence of genotoxicity in humans
Information Section
857
rhinitis caused by this biocide (Moscato G. et aL, OccupationalMedicme 1997, 47, 249).
workers (Lim C.H. et aL, IndustrialHealth 1997, 35, 278).
Methyl tert-butyl ether testing
Tripropylene glycol diacrylate--a skin carcinogen In mice
The results of a large toxicology programme on this fuel oxygenate--cortducted under the auspices of an industry task force responding to TSCA-driven objectives--are reported in a supplement to the Journal of Applied Toxicology. Animal studies include examination of reproductive and developmental toxicity, carcinogenicity and in vivo mutagenicity (Journal of Applied Toxicology 1997, 17 (Suppl. 1), $1).
2,2',3,3',4,4'-Hexachlorobiphenyl subchronic toxicity in rats In a 13-week dietary" study in rats, 2,2',3,Y,4,4'hexachlorobiphenyl (PCB 128) produced pathological changes in the thyroid at 0.05 ppm (about 4 rLg/kg body weight/day), the lowest tested dose. Treatment-induced liver changes also possibly occurred at this dose, and were certainly present at 0.5 ppm (Lecavalier P. et al., Journal of Toxicology and Environmental Health 1997, 51,265).
Chronic inhalatiion toxicity of methyl methacrylate Male and female rat.'; exposed to methyl methacrylate vapou]m at concentrations of about 100 and 400 ppm fo:: up to 2 years developed concentration-deperLdent microscopic changes in their nasal cavities (degenerative, regenerative and inflammatory effects). The no-observed-effect level was probably 25 ppm. Hamsters exposed to the same concentrations for up to 18 months showed no such effects. The:re was no evidence of carcinogenicity in either species (Lomax L.G. et al., Food and Chemical Toxicology 1997, 35, 393).
2-Bromopropane and reproductive toxicity in mice 2-Bromopropane (BI?) was the suspectedcauseof serious occupational health problems at an electronic company in Korea (BIBRA Bull. 1996, 35, 370). In an attempt to clarify the role of BP, a study has been conducted in female mice treated (intraperitoneally) fi)r 21 days before and during mating. The adverse effects (reduced fertility, delayed oestrous cycle and decreased ovarian weight), some present even at the lowest dose of 300 mg/kg body weight/day, have led the Korean investigators to conclude that BP was the likely cause of the menstrual problems seen in the female
A brief citation notes that tripropylene glycol diacrylate induced skin tumours (papillomas) when applied dermally as a 10 gM solution to transgenic mice 3 times/week for 20 weeks at a dose of 0.01 mg/kg body weight. No such effect was seen at 0.002 mg/kg body weight. Concurrently run genotoxicity studies (DNA damage and induction of micronuclei in blood cells) gave no evidence of an effect at 0.02 mg/kg body weight, the highest dose tested (Tice R.R. et al., Environmental and MolecularMutagenesis 1997, 29, 240).
Water fluoridation~no evidence of genotoxicity in humans In a comparison of three groups of 63-70 Indiana residents, each with over 30 years' exposure to fluoride in the drinking water, those exposed at 4.0 ppm showed a slight, but statistically significant (P < 0.001), increase in the frequency of sister chromatid exchanges (SCEs) in their blood lymphocytes compared with those exposed at the 'optimal' or 'suboptimal' fluoridation levels of 1.0 or 0.2 ppm. A follow-up study within the highfluoride (4.0 ppm) community provided no evidence that fluoride was responsible, as the SCE frequency was no greater in 30 individuals from the original study group than in 28 from the same community who had used a private well as their primary source of drinking water for the preceding 30 years (< 0.3 ppm fluoride) (Jackson R.D. et al., Environmental and Molecular Mutagenesis 1997, 29, 265).
Alzheimer's disease a n d aluminium A U K study comparing 106 men with Alzheimer's disease with over 750 hospital controls found no link between the levels of aluminium in drinking water and the risk of developing the disease. The mean level of aluminium in the highest category of exposure was 0.2 mg/litre 0VIartyn C.N. et al., Epidemiology 1997, 8, 281).
Aluminium neurotoxicity in premature babies A study of premature babies being fed intravenously indicated that the feeding solutions routinely used in the US and Europe may be markedly impairing neurological development due
857
rhinitis caused by this biocide (Moscato G. et aL, OccupationalMedicme 1997, 47, 249).
workers (Lim C.H. et aL, IndustrialHealth 1997, 35, 278).
Methyl tert-butyl ether testing
Tripropylene glycol diacrylate--a skin carcinogen In mice
The results of a large toxicology programme on this fuel oxygenate--cortducted under the auspices of an industry task force responding to TSCA-driven objectives--are reported in a supplement to the Journal of Applied Toxicology. Animal studies include examination of reproductive and developmental toxicity, carcinogenicity and in vivo mutagenicity (Journal of Applied Toxicology 1997, 17 (Suppl. 1), $1).
2,2',3,3',4,4'-Hexachlorobiphenyl subchronic toxicity in rats In a 13-week dietary" study in rats, 2,2',3,Y,4,4'hexachlorobiphenyl (PCB 128) produced pathological changes in the thyroid at 0.05 ppm (about 4 rLg/kg body weight/day), the lowest tested dose. Treatment-induced liver changes also possibly occurred at this dose, and were certainly present at 0.5 ppm (Lecavalier P. et al., Journal of Toxicology and Environmental Health 1997, 51,265).
Chronic inhalatiion toxicity of methyl methacrylate Male and female rat.'; exposed to methyl methacrylate vapou]m at concentrations of about 100 and 400 ppm fo:: up to 2 years developed concentration-deperLdent microscopic changes in their nasal cavities (degenerative, regenerative and inflammatory effects). The no-observed-effect level was probably 25 ppm. Hamsters exposed to the same concentrations for up to 18 months showed no such effects. The:re was no evidence of carcinogenicity in either species (Lomax L.G. et al., Food and Chemical Toxicology 1997, 35, 393).
2-Bromopropane and reproductive toxicity in mice 2-Bromopropane (BI?) was the suspectedcauseof serious occupational health problems at an electronic company in Korea (BIBRA Bull. 1996, 35, 370). In an attempt to clarify the role of BP, a study has been conducted in female mice treated (intraperitoneally) fi)r 21 days before and during mating. The adverse effects (reduced fertility, delayed oestrous cycle and decreased ovarian weight), some present even at the lowest dose of 300 mg/kg body weight/day, have led the Korean investigators to conclude that BP was the likely cause of the menstrual problems seen in the female
A brief citation notes that tripropylene glycol diacrylate induced skin tumours (papillomas) when applied dermally as a 10 gM solution to transgenic mice 3 times/week for 20 weeks at a dose of 0.01 mg/kg body weight. No such effect was seen at 0.002 mg/kg body weight. Concurrently run genotoxicity studies (DNA damage and induction of micronuclei in blood cells) gave no evidence of an effect at 0.02 mg/kg body weight, the highest dose tested (Tice R.R. et al., Environmental and MolecularMutagenesis 1997, 29, 240).
Water fluoridation~no evidence of genotoxicity in humans In a comparison of three groups of 63-70 Indiana residents, each with over 30 years' exposure to fluoride in the drinking water, those exposed at 4.0 ppm showed a slight, but statistically significant (P < 0.001), increase in the frequency of sister chromatid exchanges (SCEs) in their blood lymphocytes compared with those exposed at the 'optimal' or 'suboptimal' fluoridation levels of 1.0 or 0.2 ppm. A follow-up study within the highfluoride (4.0 ppm) community provided no evidence that fluoride was responsible, as the SCE frequency was no greater in 30 individuals from the original study group than in 28 from the same community who had used a private well as their primary source of drinking water for the preceding 30 years (< 0.3 ppm fluoride) (Jackson R.D. et al., Environmental and Molecular Mutagenesis 1997, 29, 265).
Alzheimer's disease a n d aluminium A U K study comparing 106 men with Alzheimer's disease with over 750 hospital controls found no link between the levels of aluminium in drinking water and the risk of developing the disease. The mean level of aluminium in the highest category of exposure was 0.2 mg/litre 0VIartyn C.N. et al., Epidemiology 1997, 8, 281).
Aluminium neurotoxicity in premature babies A study of premature babies being fed intravenously indicated that the feeding solutions routinely used in the US and Europe may be markedly impairing neurological development due