• Journal of Environmental Health Sciences
• /
• v.37 no.6
• /
• pp.429-439
• /
• 2011

Objectives: Ethylene oxide (EtO) is classified as a human carcinogen, but EtO is still widely used to sterilize heat-sensitive materials in hospitals. Employees working around sterilizers are exposed to EtO after sterilization. The aim of the present study was to assess the exposure of EtO level, coupled with occupationally induced micronuclei from hospital workers. The influence of genetic polymorphisms of detoxifying genes (GSTT1 and GSTM1) and DNA repair genes (XRCC1 and XRCC3) on the frequencies of micronuclei in relation to exposure of EtO was also investigated. Methods: The study population was composed of 35 occupationally exposed workers to EtO, 18 student controls and 44 unexposed hospital controls in Korea. Exposure to EtO is measured by passive personal samplers. We analyzed the frequencies of micronuclei by performing cytokinesis-block micronucleus assay (CBMN assay) and GSTM1, GSTT1, XRCC1, and XRCC3 were also genotyped by performing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The frequencies of micronuclei in EtO exposure group, student controls and hospital controls were $18.00{\pm}7.73$, $10.47{\pm}7.96$ and $13.86{\pm}6.35$ respectively and their differences were statistically significant, but no significant differences according to the level of EtO were observed. There was a dose-response relationship between the frequencies of micronuclei and cumulative dose of EtO, but no significantly differences were observed. We also investigated the influence of genetic polymorphisms (GSTM1, GSTT1, XRCC1, and XRCC3) on the frequencies of micronuclei, but there were no differences in the frequencies of micronuclei by genetic polymorphisms. Conclusions: The frequencies of micronuclei in EtO exposure group was significantly higher than control groups. A dose-response relationship was found between the level of EtO exposure and the frequencies of micronuclei, but no statistically differences were observed. We also found that the frequencies of micronuclei were increased according to cumulative EtO level. There was no association of the genetic GSTM1, GSTT1, XRCC1, and XRCC3 state with the frequency of micronuclei induced by EtO exposure.

• Korean Journal of Microbiology
• /
• v.51 no.2
• /
• pp.126-132
• /
• 2015

Three different methods (simple washing of plastic and pulp sample, washing after direct heating of the diapers, and the heating after washing of plastic and pulp sample) were carried out to decrease total coliforms and heterotrophic plate count (HPC) in the diaper's plastic and pulp. Plastic and pulp samples were obtained from diaper by treatment with 10% $CaCl_2$ and 4% sea salt water, dilution with 1,000 ml tap water, and draining by using sieves. Three times washing was the most appropriate for the reduction of microorganisms in plastic and pulp. By three times washing, the number of total coliforms in the plastic and pulp samples showed 92.8% and 99.8% of decrease, respectively, and the number of HPC showed 97.3% of decrease in the plastic and 98.5% of decrease in the pulp. The washing after direct heating of the fecal contaminated diapers was not effective because HPC in the plastic and pulp samples were still detected about 2-3 log CFU/g in the plastic and 1-2 log CFU/g in the pulp, respectively, even after heating at $60^{\circ}C$, $80^{\circ}C$, $100^{\circ}C$ for 12 h. Meanwhile, total coliforms and HPC were completely sterilized at $80^{\circ}C$ for 4 h by heating after washing of plastic and pulp samples, suggesting that this method was the most appropriate method for the reduction of microorganisms in plastic and pulp obtained from fecal contaminated diapers.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.2
• /
• pp.166-172
• /
• 2002

The top shell, Omphalius pfeifferi capenteri meat vacuum-packed in can (diameter$\times$height, 74.1mm$\times$50.7mm) were heated at 115$^{\circ}C$ up to $F_0$ values of 5 min, 10 min, 15 min and 20 min, and the changes in food components were studied. After 14 days storage at 37$^{\circ}C$ and 55$^{\circ}C$, no growth of microorganism and panelling were recognized from the canned meats which were sterlized at 115$^{\circ}C$ with $F_0$ value of S min and over. In the case of proximate composition of the canned meats, the moisture content decreased with the increase of $F_0$ value, while crude protein increased. The increase of volatile basic nitrogen content, pH and degree of browning and the decrease of mineral, total amino acid, free amino acid, trimethylamine oxide, total creatinine contents and yields were observed during thermal processing, In sensory evaluation on color, texture and taste in the canned meats, no significant difference was observed among a boiled sample and the canned meats heated at re value of 10 min and below. But, in the canned meats heated at $F_0$ value of over 15 min, its sensory scores decreased with the increase of $F_0$ value. From these results, the reasonable $F_0$ value for preparation of the heat-treated top shell meats was in the range of 5$\~$10 min.

• Applied Biological Chemistry
• /
• v.22 no.3
• /
• pp.160-165
• /
• 1979

This study was carried out to investigate effects of iron content on the quality of soy sauce, bean paste and red pepper paste, and to elucidate the origin of iron and change of the contents during production processes. For the first step, the iron contents in commercial soy sauce and changes of the contents during brewing process were determined. The results obtained were as follows. 1, Iron contents of raw materials were 108 ppm in soy bean, 133ppm in defatted soy bean, 79 ppm in wheat, 5 ppm in sodium chloride, 58 ppm in seed koji, 300-2000 ppm in spore of Aspergillus oryzae, 240 ppm in wheat gluten, 20 ppm in sodium carbonate (above figures were of dry weight basis), 6 ppm in hydrochloric acid, 18 ppm in caramel and 0.3ppm in brewing water respectively. 2, Iron contents in koji were 200-240 ppm (as dry weight basis) and increased, more or less, in progress of koji-making period. 3. Iron contents in the mashes during fermentation were 40 rpm after 1 month, 43-47 ppm after 3 months and 49-62ppm after 6 months. 4. In chemical soy sauce, the iron content was 159 ppm after hydrolysis of wheat gluten with hydrochloric acid, and 184 ppm after neutralization. 5. Higher iron contents were detected both in fermented and chemical soy sauce when the concentration of total nitrogen increased, but the levels were higher in chemical soy sauce than in fermented one at the same concentration of total nitrogen. 6. In the case of fermented soy sauce, the iron content in the filtrate was decreased by press-filtration, but no significant change was found between before and after heat-sterilization. 7. Iron contents in commercial soy sauce were varied with the producers, however, the average value was 62.7 ppm as calculated as 1.0 percent of total nitrogen. And the average level of iron in home-made soy sauce produced by conventional method was 37.68 ppm.