Animal cancer bioassays are available by inhalation a condensate from a mixture of air-rectified and vacuum residue and dermal routes of exposure bitumen fume condensates and solutions of bitumen in solvent.
Одно из зданий на периферии Парка неожиданно исчезло, и на его месте немедленно появилось другое -- совершенно иной архитектуры. Превращение произошло настолько стремительно что, мигни Олвин именно в этот момент, и он ничего бы уже не заметил. В изумлении смотрел он на слегка изменившийся город, но даже и в этот миг потрясения от увиденного мозг его искал объяснений.
Ему вспомнились появившиеся на экране слова: Регрессия начнется.
Two key epidemiological studies in European asphalt workersare also available. Inhalation Study It is important to recognize that toxicity studies involving exposure to bitumen fumes represent only the volatile fraction of the whole material.
Mult mai mult decât documente.
No chronic cancer inhalation study on bitumen has been performed. The read across was based on the transitional cell papilloma nose that the fumes of this material have been assessed and compared with fumes from straight-run paving bitumen and found to be comparable in composition and physical properties.
With regard to the read-across inhalation study, a two-year bioassay papillomavirus sur un homme fumes from a mixture of air-rectified bitumen and vacuum residue was conducted in Wistar rats Crl: WI WU BR Fuhst These concentrations were chosen based on transitional cell papilloma nose series of range-finding experiments in which the animals at the highest dose showed signs of slight respiratory irritation.
The mean actual concentrations in the study, measured as total hydrocarbon sum of aerosol and vapourwere 0, 4. Note: taking into account the conversion factor of 1.
Additional control animals 36 and animals exposed to the high dose 36 were included in the study to conduct bronchio-alveolar lavage and to investigate proliferation of respiratory epithelia, at 7 days, 90 days and 12 months following the start of exposure. A statistically-significant reduction in body weight gain was observed in the medium-dose groups from day males and females and in the high-dose groups as of day 21 males or day 28 females.
Lactic dehydrogenase activity in fluid, indicating an increased permeability of cell membranes, was slightly elevated in the exposed females but not males.
Disease of Paranasal Sinuses(1)
However, the absolute values were low transitional cell papilloma nose below the values of historical controls and were considered of minor relevance by the investigators. Gamma-glutamyltransferase levels in fluid, indicative of increased phagocytitic activity of macrophages, were slightly increased in both males and females.
Overall results of investigations showed that effects, if any, were very slight to slight. The authors conclude that the broncheoalveolar region of the respiratory tract is not significantly impacted by exposure oxidized air-rectified asphalt fume.
Unit Length Labelling Index was comparable in lung parenchyma of treated and control animals. No consistent effects transitional cell papilloma nose cell proliferation were seen for level 1 respiratory epithelium, level 1 non-ciliated epithelium and level 3 olfactory epithelium.
Я почти забыл.
- Residues (petroleum), vacuum - Registration Dossier - ECHA
- Papilloma virus gyogyitasa
The only consistent increase in proliferation was seen in the transitional zone of respiratory to olfactory epithelium in the exposed males, but not females. At the mid-dose level In particular hyperplasia of mucous cells goblet cells and eosinophilic cytoplasmic inclusions in the olfactory epithelium transitional cell papilloma nose observed. In addition, a statistically-significant increased incidence of mononuclear cell infiltrates was seen transitional cell papilloma nose the epithelium of the nasal and para-nasal cavities in animals of the mid- and high-dose groups.
These effects were also seen at a lower incidence in the animals of the control and low-dose groups and are probably adaptive transitional cell papilloma nose nature. No increases in the number of tumour-bearing animals were observed among the groups, nor were any statistically-significant increases in organ-related tumour incidences found in exposed animals compared to the controls.
It was concluded that the fumes from a sample of mixed air-rectified asphalt and vacuum residue were not carcinogenic to rats.
Dermal Studies A relatively large number of mouse skin-painting studies have been performed. Most of these involve dermal application of dilutions of bitumen, using a variety of transitional cell papilloma nose.
In addition, a limited number of skin painting experiments have been performed using condensates of fumes derived from heating bitumens or condensates of fumes collected from the headspace of heated storage tanks. In a key carcinogenicity dermal skin painting study Clark et al.
И игрой, которую он не сможет разделить ни с кем, и сама по себе она не даст ему. И все же на это стоит пойти хотя бы только для того, чтобы унять душевную тоску. Словно не желая возвращаться в знакомый мир, Олвин бродил и бродил среди отражений прошлого.
Aliquots The total weekly dose of fume condensate was 50 mg. In the negative control group mineral oil vehicle control one mouse developed a basal cell carcinoma.
In the mice treated with paving asphalt fume condensate, a single animal with a squamous cell papilloma was found transitional cell papilloma nose terminal sacrifice week In addition, tumours observed in other organs were within the incidence range of historical controls for this strain and not considered significant.
The positive control benzo[a]pyrene BaP0. Five supporting dermal cancer studies on bitumen were identified. In a dermal carcinogenicity study Goyak et al. Benzo[a]pyrene [BaP] 0.
Disease of Paranasal Sinuses(1)
Survivorship was unaffected by treatment. Treated animals, as well as mineral oil treated animals, were generally free of dermal irritation during the course of the study and upon histopathological examination. Animals treated with BaP and its vehicle, toluene, exhibited slight-to-moderate dermal irritation throughout the study.
No tumors were observed in animals treated with the bitumens or the vehicle controls toluene and mineral oil. Of the tumor-bearing animals, 45 developed squamous cell carcinomas, while one animal developed a papilloma.
In another dermal skin painting study Hueper et al. The test materials included 3 paving grade steam refined bitumens and 1 paving grade steam-vacuum refined bitumen. The carcinogenic potential of 8 bitumens was investigated in a skin painting study in Swiss mice Wallcave et al.