• Tunnel and Underground Space
• /
• v.22 no.3
• /
• pp.163-172
• /
• 2012

As more diesel engines have been employed in underground limestone mines with large cross section, underground space environment is worsened by diesel exhausts and heat flow. This paper aims for the ultimate goal to optimize the work place environment through assuring the optimal required ventilation rate based on the analysis of the airflow, diesel exhaust gas concentrations and the effects of mechanization and deepening working face on temperature and humidity. Due to the insufficient capacity of the main exhaust fan and poor airway management, stagnant airflows were observed at various locations, while the flow direction was reversed instantly with passing diesel equipment and the flow reversal was also made by the seasonal variation of the outside surface weather. During the loading operation, CO concentration measurements were found to be frequently higher than the threshold limit of 50 ppm, and most of the $NO_2$ measurements during drilling and loading operations shows even more serious levels surpassing the permissible limit of 3 ppm. The actual ventilation quantity was considerably less than the required quantity estimated by the mine health and safety law, and this shortage problem was less serious in colder winter showing more effectiveness of the natural ventilation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.15 no.3
• /
• pp.207-212
• /
• 1986

Heavy metal contents and residues level of organochlorine pesticides were analyzed for commercial salted and fermented sea-food which bought from pusan area. Heavy metal contents ranged from 0.11 to 0.46 ppm of mercury, trace to 1.1 ppm of lead, 0.01 to 0.34 ppm of cadmium, 0.4 to 5.98 ppm of cupper, 0.16 to 4.5 ppm of zinc, trace to 0.49 ppm of manganese and trace to 1.35 ppm of arsenic. Residue level of organochlorine pesticides in salted and fermented sea-foods ranged from 0.3 ppb to 1.825 ppb of total BHC Organochlorine pesticides of DDE, dieldrine, pp'-DDD and pp'-DDT were detected a small amount from Ge jeot and Myeol-Chi jeot. In conclusion. the heavy metal and levels of organochlorine pesticides residues were safety to eat the salted and fermented sea foods.

• Journal of Convergence Society for SMB
• /
• v.3 no.2
• /
• pp.27-32
• /
• 2013

Wireless Body Area Networks (WBAN) have been made possible by the emergence of small and lightweight wireless systems such as Bluetooth, enabled devices and PDAs. Antennas are an essential part of any WBAN system and due to various technical requirements and physical constraints, careful consideration of their design and deployment is needed. This paper is proposing on the design of wearable antenna as parts of clothing to serve communications functions, such as tracking and navigation in health care applications. The substrates of the wearable antennas will be made from textile materials and since it is wearable, it should have a small size, be light weight, low maintenance, and unobtrusive. This proposed paper will also investigate the influence of different parameters for wearable antenna including types of textile/substrate to ensure that the antenna design satisfies WBAN requirements. The characteristics and behavior of the antenna need to adhere to specifications set by wireless standards and system technology requirements. This means that the transmitting and receiving frequency bands of the various units need to be chosen accordingly. Since there are restrictions on the level of power to which the human body can be exposed to, the antenna as well as other RF system components must be designed to meet these restrictions. Antenna gain, which directly affects power transmitted, is a critical parameter in ensuring power levels fall within the safety guidelines and so will be of primary importance in the design. The electromagnetic interaction between WBAN antennas and devices and the human body will also be explored.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.6
• /
• pp.753-758
• /
• 2007

To assess the safety of solar salts of Jeollanamdo province where most of Korean solar salts are produced, 433 samples of solar salts in total were collected and analyzed for their contents of sodium chloride and heavy metals (lead, cadmium, arsenic and mercury). Sodium chloride contents ranged from 80 to 85% in 63% of solar salts analyzed. Lead was not detected in 77% of solar salt samples and showed a value of below the maximum permissible limit (2 ppm) in other samples. Cadmium was not detected in most samples (78%), and the other samples where cadmium was detected showed a value far below the maximum permissible limit (0.5 ppm) except for three ones. Arsenic was detected in only four samples, but their concentrations were far below the permissible limit (0.1 ppm). Mercury was not detected in all samples. There were some differences between producing areas in the levels of sodium chloride and lead of solar salts, but the contents of cadmium, arsenic and mercury did not show significant regional differences. These results clearly indicate that solar salts produced from Jeollanamdo province are safe in the aspects of lead, cadmium, arsenic and mercury contents.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.3
• /
• pp.169-174
• /
• 2001

This study was conducted to compare and evaluate the heavy metal contents of agricultural products in Korea and to compare with relevant international criteria such as the Average Daily Intake(ADI) and the Provisional Tolerable Weekly Intake(PTWI) proposed by the joint FAO/WHO Codex Committee on additives and contaminant. Contents of heavy metal in cereals, pulses, potatoes, vegetables and fruits were in the range of $0.010{\sim}0.073$ for Cd, $0.40{\sim}6.45$ for Cu, $0.083{\sim}0.698$ for Pb, $2.45{\sim}16.30$ for Zn, $0.171{\sim}1.378$ for Ni, $0.023{\sim}0.233$ for Cr and $0.026{\sim}0.070$ mg/kg(F.W.) for As. Heavy metal contents of cereals, pulses, potatoes, vegetables and fruits were with natural content levels proposed by FAO/WHO and were similar to value monitored in other countries. Also, average intake of heavy metal from agricultural products was lower than the ADI and PTWI by the joint FAO/WHO Codex Committee on Additives and Contaminants. Therefore, none of the cereals, pulses, potatoes, vegetables and fruits evaluated showed accumulation of such heavy metal high enough to cause health problems to human.

• The Korean Journal of Pesticide Science
• /
• v.15 no.4
• /
• pp.357-365
• /
• 2011

Exposure measurement of agricultural worker to pesticide is one of important part of health risk assessment of pesticide. Therefore exposure matrices, apparatus, instruments and methods must be validated in advance to field experiment. In this study, method validation with an organophosphorus insecticide fenthion was carried out for exposure monitoring of agricultural worker. LOD and LOQ were 0.01 and 0.05 ng, respectively. Calibration curve linearity ($R^2$ > 0.999) and reproducibility (C.V. < 3%) were also excellent. Recovery at LOQ, 10LOQ and 100LOQ levels from gloves, socks, mask, patch, solid sorbent, glass fiber filter was 76~113% (C.V. < 3%). Trapping efficiency was 95~105% while no breakthrough was observed. Method validation for the exposure monitoring was established successfully through several experiments. Such method validation can be usually performed in laboratory and not much different for each pesticide so that, this techniques will be applied widely in research for pesticide exposure monitoring by combination with body surface area and respiration rates.

• Journal of the Korean Regional Science Association
• /
• v.39 no.3
• /
• pp.65-83
• /
• 2023

The purpose of this study is to conceptually define "spatial inclusivity" and empirically examine the impact of disability severity and spatial inclusivity on social participation among individuals experiencing physical discomfort. The social and spatial environment of the residential area is crucial for individuals with disabilities who face limited activity range and complex barriers due to physical constraints. In this study, spatial inclusivity from the perspective of people with disabilities is defined as establishment of equal relationships with non-disabled individuals within the local community, as well as the availability of basic facilities and services in a safe urban space that allows for access and utilization. This concept consists of three dimensions: individual networks, social environment, and physical environment. The physical environment encompasses safety levels, natural environment, living environment, public transportation conditions, medical services in residential areas. We used the 2019 Community Health Survey to examine the relationship between disability severity, spatial inclusivity, and social participation using a two level regression model. The findings are as follows: Firstly, personal relationships at the individual level and the physical environment at the local level have a positive impact on social participation. Secondly, when identifying dividing the physical environment into five sub-factors, no significant influence of individual factors is found. Thirdly, trustworthy and friendly social environment at the local level has a negative impact on social participation. These results provide empirical evidence that spatial inclusivity has an effect on the social participation of individuals with disabilities and suggest implications for urban planning to create and enhance conditions for the social participation of individuals with disabilities.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.3
• /
• pp.211-216
• /
• 2010

On 7 December 2007, about 12,547 kL of crude oil spilled from the Hong Kong registered tanker Hebei Spirit along the west coast of the Republic of Korea, including Taean-gun, Chungcheongnamdo Province. This study evaluated the safety of seafood collected from the coastal area polluted by the crude oil. The range of total polycyclic aromatic hydrocarbons (${\sum}PAHs$) at 22 stations was 3.9-37.1 ng/g. The concentration of ${\sum}PAHs$ was higher in oysters, Crassoatrea gias, than that in short-necked clams, Ruditapes philippinarum. Benzo(a)pyrene, a highly toxic PAH, ranged from 0.07-1.47 ng/g, which did not exceed the European Union regulatory limit for benzo(a)pyrene. The toxicity equivalent of benzo(a)pyrene in oysters and short-necked clams was 0.49-1.70 and 0.09-1.01 ng/g, respectively. The estimated life time cancer risk was very low, i.e., $1.31{\times}10^{-8}$ for the oysters and $6.9{\times}10^{-9}$ for the short-necked clams. The body burden of PAHs in bivalves originated mostly from petroleum contamination, but the levels was not sufficiently high to harm human health.

• Fire Science and Engineering
• /
• v.33 no.4
• /
• pp.140-151
• /
• 2019

It is to assess the indoor air quality of the chemical hazardous materials exposed to the fire after firefighters returned to the fire scene. The research subject randomly selected four fire stations located in Seoul, Korea. Two fire stations were set up as control groups after the return of the firefighting activities at the actual fire scene, and two other fire stations were set up as control groups to measure the air quality of the room at normal levels regardless of the action. We conducted 24-hour monitoring for all fire accidents that occurred in Seoul Metropolitan using fire safety map computer system. Also, indoor air quality was measured immediately after homecoming if the experiment group was to be dispatched due to an accident of intermediate or larger scale. 11 hazardous substance items such as fine dust, formaldehyde, volatile organic compounds, PAH, VCM, acidity, asbestos, CO₂, NO₂, O₃ were measured according to the process test method. Three of 11 types of harmful substances exceeded domestic and foreign standards, and one of them was found to be close to foreign standards. In particular, total volatile organic compounds, carbon dioxide and sulfuric acids were 2.5 times, 2.2 times and 1.1 times higher than the standard. Also, for formaldehyde and sulfuric acid, it was measured higher in the control group than in the case group. This findings could be used in policies to improve indoor air quality in the fire station of the Seoul Metropolitan Government.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.252-260
• /
• 2021

For frailty management, the importance of resistance exercise has been emphasized, and various devices have been developed. Recently, digital weight control technology that converts electromagnetic resistance to a digital weight is attracting attention, but there are no reports confirming the effectiveness and safety of the device for seniors in Korea. This study conducted a biomechanic-based ergonomic analysis of an elderly-friendly exercise device utilized in digital load control technology to suggest a direction for development. Twenty seniors (age: 62.40 ± 2.09 years) were included. The load of the device was classified into three levels, and the muscle activity and heart rate were assessed during three experimental motions. A questionnaire based on the International Organization for Standardization 9241-11 was adopted to evaluate the stability, operationality, efficiency, and satisfaction with the software and device. The program could be divided into three exercise intensities that can be utilized in the field depending on whether the exercise load, muscle activity, and heart rate were consistent. The monitor size needed to be enlarged to make the menu Korean, reduce the device size, and minimize noise. Considering these findings, the development of an advanced age-friendly exercise device by improving the size, display, and noise is suggested.