- Email: [email protected]
Smoking and sudden infant death syndrome
Information Section
carcinoma were seen in subjects exposed to fibreglass dust, dry-cleaning agents, asbestos dust and luminous paint. “Although solar W radiation is known to be the major environmental exposure causing nonmelanocytic skin cancer, results of this study suggest that nonslolar factors may also be important” (Gallagher RP. et al., Chncer Epidemiology, Biomarkew and Prevention 1996,5, 419).
Mobile phones an’d the chromosomes Microwave radiation of a mobile telephone frequency has been shown to enhance the activity of a known genotoxin, mitomycin C. Lymphocyte cultures were incubated with mitomycin C following the exposure of human blood samples to 954 MHz waves from a mobile communication network base station for 2 hr. Microwave exposure alone induced no chromosome effect (sister chromatid exchanges), but had a synergistic action on the response of the lymphocytes to mitomycin C. The investigators cautioned against extrapolation of the results to cellular phone users, but noted the exposure conditions were relevant to workers in the telecommunications sector (Maes A. et al., Environmental and MolecukarMutagenesis 1996,28, 26).
Blindness from pplhenylenediamine ingestion A 24yr-old Sudanese m.an who ingested around 7 g of pphenylenediamine in the form of a hair dye developed breathing difficulties, a swollen face and neck and became blind. He was stil1 blind when he was examined six months later (Yagi H. et af., Hwnun and Experimental Toxicology 1996, 15,617).
Nicotine - addictive oc not? The conclusion that nic:otine is inherently addictive (and not just ‘habit-forming’) is stil1 subject to debate. Evidente that supports the ‘addictive’ view has recently been published by investigators from Italy. Rats receiving smal1 intravenous doses of nicotine-corresponding to a leve1 which the animals wil1 self-administer-showed an increase in the release of the neurotransmitter dopamine and an activation of energy metabolism in the same specific region of the forebrain (the nucleus accumbens) that is simi:larly activated by cocaine, amphetamine and morphine and is thought to play a role in the rewarding effects of these drugs. The “results provide . . . evid.ence that there are specific
1195
neurobiological commonalities between nicotine and addictive drugs” (Pontieri F.E. et al., Nature 1996,382,255).
Smoking and sudden infant death syndrome A recent study has led to the suggestion that the incidence of tot deaths could be reduced by almost two-thirds if parents did not smoke. In a 2-yr investigation of three regions of Britain with a total population of 17 million, 195 tot deaths were investigated and compared with 780 matched controls. Smoking during pregnancy was associated with an increased risk of tot death (RR after controlling for other factors 1.78,95% CI 1.04-3.05). However, the risks associated with tobacco smoke were not restricted to exposure prior to birth, but rose with increasing postnatal exposure (odds ratios rose with increasing numbers of smokers in the household, increasing numbers of cigarettes smoked daily and estimated duration of exposure of the infant to tobacco smoke) (Blair P.S. et al., British Medical Joumal 1996,313, 195). Additional analysis of the data revealed bed-sharing with mothers who smoke to be a further factor significantly associated with an increased risk of sudden infant death syndrome (odds ratio 9.25,95% CI 2.51-34.02) (Fleming P.J. et al., British Medical Journall996, 313, 191).
Skin absorption - importante of the solvent In an investigation of the absorption of phenol and pnitrophenol through isolated perfused pig skin, the US investigators demonstrated that, on covered application, the choice of vehicle had a greater influence than did the concentration of the chemical. Significantly greater absorption was observed with acetone as the vehicle than with ethanol (Brooks J.D. and Riviere J.E., Fundamental and Applied Toxicology 1996,32,233).
Subchronic oral toxicity of 1,3-dichloropropene in rodents The stomach was identified as the target organ in male and female rats fed 15 mg/kg body weight/ day and above in their diet for 13 wk. NO specific target tissues were identified in mice similarly treated with up to 175 mg/kg body weight/day. The only sign of toxicity at the lowest tested doses (5 mg/kg body weight/day in the rat and 15 mg/kg body weight/day in the mouse) was a slight
carcinoma were seen in subjects exposed to fibreglass dust, dry-cleaning agents, asbestos dust and luminous paint. “Although solar W radiation is known to be the major environmental exposure causing nonmelanocytic skin cancer, results of this study suggest that nonslolar factors may also be important” (Gallagher RP. et al., Chncer Epidemiology, Biomarkew and Prevention 1996,5, 419).
Mobile phones an’d the chromosomes Microwave radiation of a mobile telephone frequency has been shown to enhance the activity of a known genotoxin, mitomycin C. Lymphocyte cultures were incubated with mitomycin C following the exposure of human blood samples to 954 MHz waves from a mobile communication network base station for 2 hr. Microwave exposure alone induced no chromosome effect (sister chromatid exchanges), but had a synergistic action on the response of the lymphocytes to mitomycin C. The investigators cautioned against extrapolation of the results to cellular phone users, but noted the exposure conditions were relevant to workers in the telecommunications sector (Maes A. et al., Environmental and MolecukarMutagenesis 1996,28, 26).
Blindness from pplhenylenediamine ingestion A 24yr-old Sudanese m.an who ingested around 7 g of pphenylenediamine in the form of a hair dye developed breathing difficulties, a swollen face and neck and became blind. He was stil1 blind when he was examined six months later (Yagi H. et af., Hwnun and Experimental Toxicology 1996, 15,617).
Nicotine - addictive oc not? The conclusion that nic:otine is inherently addictive (and not just ‘habit-forming’) is stil1 subject to debate. Evidente that supports the ‘addictive’ view has recently been published by investigators from Italy. Rats receiving smal1 intravenous doses of nicotine-corresponding to a leve1 which the animals wil1 self-administer-showed an increase in the release of the neurotransmitter dopamine and an activation of energy metabolism in the same specific region of the forebrain (the nucleus accumbens) that is simi:larly activated by cocaine, amphetamine and morphine and is thought to play a role in the rewarding effects of these drugs. The “results provide . . . evid.ence that there are specific
1195
neurobiological commonalities between nicotine and addictive drugs” (Pontieri F.E. et al., Nature 1996,382,255).
Smoking and sudden infant death syndrome A recent study has led to the suggestion that the incidence of tot deaths could be reduced by almost two-thirds if parents did not smoke. In a 2-yr investigation of three regions of Britain with a total population of 17 million, 195 tot deaths were investigated and compared with 780 matched controls. Smoking during pregnancy was associated with an increased risk of tot death (RR after controlling for other factors 1.78,95% CI 1.04-3.05). However, the risks associated with tobacco smoke were not restricted to exposure prior to birth, but rose with increasing postnatal exposure (odds ratios rose with increasing numbers of smokers in the household, increasing numbers of cigarettes smoked daily and estimated duration of exposure of the infant to tobacco smoke) (Blair P.S. et al., British Medical Joumal 1996,313, 195). Additional analysis of the data revealed bed-sharing with mothers who smoke to be a further factor significantly associated with an increased risk of sudden infant death syndrome (odds ratio 9.25,95% CI 2.51-34.02) (Fleming P.J. et al., British Medical Journall996, 313, 191).
Skin absorption - importante of the solvent In an investigation of the absorption of phenol and pnitrophenol through isolated perfused pig skin, the US investigators demonstrated that, on covered application, the choice of vehicle had a greater influence than did the concentration of the chemical. Significantly greater absorption was observed with acetone as the vehicle than with ethanol (Brooks J.D. and Riviere J.E., Fundamental and Applied Toxicology 1996,32,233).
Subchronic oral toxicity of 1,3-dichloropropene in rodents The stomach was identified as the target organ in male and female rats fed 15 mg/kg body weight/ day and above in their diet for 13 wk. NO specific target tissues were identified in mice similarly treated with up to 175 mg/kg body weight/day. The only sign of toxicity at the lowest tested doses (5 mg/kg body weight/day in the rat and 15 mg/kg body weight/day in the mouse) was a slight