Biomedical subjects
Publications and source records attributed to L D Kostenko.
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Benz(a)pyrene was detected in the ether-insoluble fraction of acidic water on being heated to 100 and 300-450 degrees C, while heating of total acidic water and settled tar at 300-450 degrees C did not cause any changes in the content of this compound. The obtained results suggest that the ether-soluble fraction of acidic water contains compounds which promote benz(a)pyrene breakdown or inhibit its synthesis from products of timber pyrolysis.
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Under study was the effect of overheating of wood pyrolysis products at 600 degrees C on the content of 3,4-benzpyrene in them. Overheating only of the water portion of pyrolysis products would increase considerably its BP content, on account of it the total output of the carcinogen is increased. While overheating of total pyrolysis products results in still greater increase of total BP output on account of its concentration rise both in the water portion and resin. Overheating of resin separately would result in a 7 times increase of BP concentration in it.
In 4 series of experiments a dependence between 3,4-benzpyrene (BP) output and the temperature of fir sawdust pyrolysis under isothermic conditions has been investigated. The experimental series differed in the duration of wood pulp particles stay in the reaction zone (tau). Also EPR spectra of pyrolysis products have been recorded. The experimental series did not differ in an output of ether extract from pyrolysis products, while BP output temperature curves in their shape were found to be largely dependent on tau: with an increased tau these curves definitely showed the maximum in the range of 300-350 degrees C and the BP output raised in the range of this maximum and also at the temperature of 600 degrees C. In the temperature range over 350 degrees C the character of dependence of the EPR signal value on temperature would correlate well with the temperature-dependent BP output, in the range of lower temperatures the EPR signal was not detected. The data obtained are considered as an evidence of two processes of BP formation in wood pyrolysis-a high-temperature process (temperature over 500 degrees C) and low-temperature one (300-350 degrees C). The high-temperature process seems to have the free-radical mechanism of BP formation, whereas in low temperatures it is evidently the result of a ion type reaction.
The content of benz(a)pyrene (BP) was studied in the grain, different sorts of flour and in talkan, a Kazakh national food product, prepared from fried grain. It was found that the grain contained 0.33 micrograms/kg of BP, flour--33-58% of that in the grain. The carcinogen content in flour varied with its kind: the highest BP concentration was detected in rye flour, the lowest--in high-quality wheat flour. In talkan, prepared from fried wheat, the content of BP was twice as much compared to the non-fried wheat, due to the intensity of frying. A man, who makes use of talkan during his life, may receive a significant amount of BP which can be conducive to raising the incidence of tumors of the digestive organs, especially of the esophagus.
Six samples of different kinds and sorts of native tea and 103 samples of tea beverage were tested for the benz(a)pyrene (BP) content. The results of the study showed that the carcinogen content in native tea varied from 2.4 micrograms/kg (in mixed tea No 36) to 3.84 micrograms/kg (in the Georgean tea, sort 1). The BP content in the tea beverage depended on the technology of its production. The carcinogen presence and its content increase in a violated technology of tea production may be an important factor in the genesis of esophagus carcinoma.