• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.4
• /
• pp.561-567
• /
• 2021

The edible sargasso seaweed hijiki Sargassum fusiforme is known to have high concentration of arsenic, which is a threat to human health, particularly due to inorganic arsenic. In this study, various methods were used to remove inorganic arsenic from steamed hijiki concentrate. The highest concentration of arsenate [As(V)] in both raw and processed hijiki during steamed hijiki manufacturing process was within the range of 8.213-14.356 mg/kg, and it is a potential source of inorganic arsenic, which can result in re-contamination and cause environmental pollution. The removal efficiencies of the various removal methods were within the range of 57.3-83.4%, and 19.0% reduction was achieved using activated carbon and alginate bead. Further, activated carbon showed the best adsorption effect of inorganic arsenic. Therefore, we suggest that activated carbon is a suitable efficient method for removing inorganic arsenic and has low operational costs in field applicability.

• Microbiology and Biotechnology Letters
• /
• v.49 no.2
• /
• pp.192-200
• /
• 2021

Kunun-zaki, produced by submerged fermentation of a combination of millet and sorghum, is a popular beverage in Northern Nigeria. Owing to the nature of the process involved in its production, kunun-zaki is highly susceptible to contamination by food spoilage microorganisms, leading to inconsistent quality and short shelf-life. In this study, we investigated various food spices, including cinnamon, garlic, and nutmeg, as potential preservatives that could be used to extend kunun-zaki shelf-life. Kunun-zaki varieties were fermented with each of these spices mentioned above and subjected to bacterial, nutritional, sensory, and quality maintenance assessments (using a twelve-member sensory panel to evaluate the organoleptic properties of kunun-zaki). Bacterial counts in the final products ranged between 10^5-7 CFU/ml. We identified two bacterial genera, Weissella and Enterococcus, based on partial 16S rRNA gene amplicon sequencing. Three amino acids, namely leucine, aspartate, and glutamate, were abundant in all kunun-zaki varieties, while the total essential amino acid content was above 39%, suggesting that kunun-zaki could potentially be considered as a protein-rich food source both for infants and adults. The kunun-zaki products were also rich in carbohydrates, crude proteins, ash, crude fiber, and fat, with contents estimated as 81-84, 8-11, 0.8-4.0, 2.9-3.58, and 5.1-6.3%, respectively. However, this nutritional content depreciated rapidly after 24 h of storage, except for kunun-zaki fermented with garlic, which its crude protein and fat content was maintained for up to 48 h. Our results revealed that organic spices increased the nutritional content of the kunun-zaki varieties and could be potentially be used as natural preservatives for enhancing the kunun-zaki shelf-life. However, garlic might be considered a better alternative based on our preliminary investigation. The presence of the isolated microorganisms in the analyzed kunun-zaki samples should be highlighted to raise awareness on the possible health hazards that could arise from poor handling and processing techniques.

• Smart Media Journal
• /
• v.7 no.4
• /
• pp.44-51
• /
• 2018

The purpose of this research is to collect atmospheric environmental information at specific altitudes in a range of 0 to 1 km above the surface and to monitor it using drones. The corresponding temperature and humidity were measured with the meteorological factors, and the amounts of fine dust and $CO_2$ were observed by the environmental factors so that they could receive the normal values. Monitoring the status of atmospheric gas emission in specific enterprises, industrial complexes and regions through the measurement is meant to help establish policies to reduce pollution factors. In conventional means previously practiced, exhaust gas detection accompanies a great deal of risks in terms of safety because the surveyor is directly exposed to the source of contamination such as the holes installed in the chimney. However, in our proposed method, the drone can collect information in a wide range under safe circumstances, which can be utilized through wide industrial areas.

• The Journal of Engineering Geology
• /
• v.29 no.2
• /
• pp.113-122
• /
• 2019

In this study, the flow analysis to evaluate the extent of groundwater decline and the effect of the small valleys caused by the decrease of groundwater level in the construction of road tunnel, and the pollutant movement analysis to evaluate pollution of nearby water source by pollutant discharge during tunnel construction, respectively. The decrease of the groundwater during the 30 month tunnel excavation period was maximum 27 m and it was found to be the largest within 50 m from the tunnel center. The flow of groundwater is shown in the form of flowing into the tunnels and the effects of groundwater level decline were observed up to a tunnel radius of 200 m. As a result of the numerical modeling of the contaminant transport to examine the influence of the polluted water discharge from the tunnel, the range of the turbid water generated at the end of the tunnel is up to 120 m and it is estimated that the risk of contamination of the small river is not large.

• Ocean and Polar Research
• /
• v.43 no.3
• /
• pp.141-148
• /
• 2021

Microplastic contamination in waterbodies is a growing source of concern for researchers and other stakeholders. We investigated oxidative stress and toxicity in goldfish (Carassius auratus) in response to exposure to 1-㎛ diameter micro-polystyrene (MP) at concentrations of 0, 10, 100, and 1000 beads/mL (MP 0, MP 10, MP 100, and MP 1000 groups) for 7 d (at day 0, 1, 3, 5, and 7). We analyzed the survival rates; superoxide dismutase (SOD) and catalase (CAT) mRNA expression levels in the liver; SOD and CAT activity in the plasma; caspase-3 mRNA expression in the liver; and the levels of hydrogen peroxide (H₂O₂) in plasma. Terminal transferase dUTP nick end labeling (TUNEL) assays were also conducted to determine apoptosis levels in the liver. All fish in the MP 1000 group died by day 7 and the MP 100 group had a lower survival rate than the MP 10 and MP 0 groups. The mRNA expression as well as SOD, CAT, and caspase-3 activity levels were increased significantly with increases in MP concentration and exposure time. Finally, according to the TUNEL assay, more apoptosis was observed in the MP 1000 group at day 5 than in other groups. In summary, MP concentrations above 100 beads/mL caused death and oxidative stress to goldfish. We conclude that MP can cause oxidative stress and apoptosis in goldfish, which leads to death.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.11
• /
• pp.1519-1527
• /
• 2020

AGeneral radiation measuring devices have been developed in the form of spatial dose rate detection devices that measure dose rates to radioactive contaminant and 2D or 3D imaging devices for radioactive contamination information. Each of these radiation detection techniques has advantages. The advantages of both detection devices are necessary to minimize personal injury and rapid decontamination in the area of a radioactive accident. In this paper, we proposed a technique that can measure the dose rate and direction information about the radioactive pollutant source in real time using a detection sensor, a rotating body, and a directional shield for radioactive pollutant detection. The rotational-based detection device is configured to check the dose rate and direction using the location information of the rotator and measurement value. We proposed a measurement technique for vertical and horizontal directions through multiple holes. It was confirmed that the measurement error for direction information was less than 1% when detected in the horizontal direction.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.12
• /
• pp.1535-1541
• /
• 2019

To carry out safe and rapid decontamination in radiological accident areas, acquisition of various information on radiation sources is needed. In particular, to figure out the location and distribution of radiation sources is essential for rapid follow-up and removal of contaminants as well as minimizing worker damage. The radiation distribution detection device is used to obtain the position and distribution information of the radiation source. In the case of a radiation distribution detection device, a detection sensor unit is generally composed of a single sensor, and the detection range is limited due to the physical characteristics of the single sensor. We applied a calibration detector for controlling the detection sensitivity of a single sensor for radiation detection and improved the limited detection range of radiation dose rate. Also, gamma irradiation test confirmed the improvement of radiation distribution detection range.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.5
• /
• pp.514-523
• /
• 2022

Concentrations of perfluoroalkyl substances (PFASs) were measured in seawater, sediment, and biota collected from Gunsan coast, Korea to investigate their occurrence, distribution, and risk of exposure to humans through seafood consumption. The total concentrations of PFASs in seawater, sediment, and biota ranged from 5.97 to 74.9 ng/L, 0.01 to 13.3 ng/g dry weight, and 0.02 to 5.73 ng/g wet weight, respectively. Predominant PFAS compounds differed across matrices, indicating that the distribution of PFASs in multiple environmental samples is governed by their carbon-chain length. The concentrations of PFASs in seawater were significantly negatively correlated with salinity (P<0.01), suggesting terrestrial input (including land-used PFASs) as the major source of PFAS contamination in coastal environments. The estimated daily intakes (EDIs) of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) through seafood consumption were 0.05 and 0.06 ng/kg body weight/day, respectively. The EDIs of PFOA and PFOS measured in this study were lower those the proposed by the United States Environmental Protection Agency and Canada guidelines, indicating limited health risk for Korean population from PFASs through consumption of seafood from Gunsan coastal environment.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.10
• /
• pp.1307-1314
• /
• 2022

In this study, we sought to investigate the various characteristics of Salmonella spp. isolated from raw chicken meats available in Korean markets. The data collected, such as food source of isolation, sampling information, serotype, virulence, and genetic profile including sequence type, were registered in the database for further comparative analysis of the strains isolated from the traceback investigation samples. To characterize serotype, virulence and gene sequences, we examined 113 domestically distributed chicken meat samples for contamination with Salmonella spp. Phylogenetic analysis was conducted on 24 strains (21.2%) of Salmonella isolated from 113 commercially available chicken meats and by-products, using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Serotyping of the isolated Salmonella spp. revealed S. Enteritidis in 11 strains (45.8%), S. Virchow in 6 strains (25%), S. Montevideo in 2 strains (8.3%), S. Bsilla in 2 strains (8.3%), S. Bareilly in 1 strain (4.2%), S. Dessau in 1 strain (4.2%), and S. Albany in 1 strain (4.2%). The genetic correlation indicated that 24 isolated strains were classified into 18 clusters with a genetic similarity of 64.4-100% between them. Eleven isolated S. Enteritidis strains were classified into 9 genotypes with a sequence identity of 74.4%, whereas the most distantly related S. Virchow was divided into five genotypes with 85.9% identity. Here, the MLST analysis indicated that the major Sequence Type (ST) of the Salmonella spp. isolated from domestic chicken sold in Chungcheong Province belongs to the ST 11 and 16, which differs from the genotype of Salmonella isolated from imported chicken. The differential sequence characteristics can be a genetic marker for identifying causative bacteria for epidemiological investigations of food poisoning.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.47 no.1
• /
• pp.12-24
• /
• 2023

Sitophilus oryzae L. (Rice Weevil) is a stored pest of rice that causes extensive loss throughout the world. We tested the leaf powders of 12 plant species viz., Chrysanthemum sp., Cinnamomum zeylanicum, Citrus grandis, Citrus limon, Gliricidia sepium, Gymnema sylvestre, Hemigraphis colorata, Michelia champaca, Moringa oleifera, Murraya koenigii, Polyalthia longifolia, and Sauropus androgynus at dosages of 1.00, 1.50, 2.00 and 3.00g against the adult rice weevil and mortality was recorded at 1, 2, 3, 5, 7, 12 and 2l days after treatment (DAT) by direct contact toxicity for their adulticidal effect. We observed 100 percent adult mortality in C. zevlanicum and M. koenigii among the tested leaf powders. In addition, the first-time tested H. colorata and S. androgynus also caused high mortality compared to other plants. All the plant powders caused moderate to high adult mortality. Hence, these plants could be effective botanical insecticides against S. oryzae as they comprise a potential source of bioactive chemicals and are generally free from toxicants. Applications of these natural derivatives in S. oryzae control could reduce the cost of control methods and storage of rice contamination. Therefore, the present study indicates that some plant extracts can be used as an alternative to toxic synthetic chemicals in the management of rice weevils.