• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.1 no.1
• /
• pp.47-55
• /
• 1991

Exposure level of respirable coal dust of underground coal mines in Taebaek area was evaluated. Personal air samplers with 10-mm nylone cyclones were attached to the coal workers including drillers, coal cutters, their assistants, haulers, and separators. Log-normality of respirable dust exposure concentration were tested by Kolmogorov-Smirnov one-sample test. Differences of means of respirable dust exposure concentration between work sites were tested by one-way ANOVA test and multiple comparison(Scheffe) test. And differences of respirable dust exposure concentration of principal and assistant workers in drilling sites and in coal faces were tested by paired t-test. Relation of respirable dust exposure concentration for the principal workers and their assistants in drilling sites and in coal faces were tested by regression analysis. The results were as follows : 1. All of the respirable dust concentration were log-normally distributed. 2. There were not only significantly different means of exposure concentration between drillers and coal cutters but between coal cutters and haulers. 3. Means of exposure concentration of drillers and drilling assistants were not significantly different. And means of exposure concentration of coal cutters and coal cutting assistants were not different.

• Journal of Biomedical Engineering Research
• /
• v.39 no.6
• /
• pp.243-249
• /
• 2018

The indoor radon concentration was measured in the lecture room of the university and the radon concentration was converted to the amount related to the radon exposure using the dose conversion convention and compared with the reference levels for the radon concentration control. The effect of indoor radon inhalation was evaluated by estimating the life effective dose and the risk of exposure. To measure the radon concentration, measurements were made with a radon meter and a dedicated analysis Capture Ver. 5.5 program in a university lecture room from January to February 2018. The radon concentration measurement was carried out for 5 consecutive hours for 24 hours after keeping the airtight condition for 12 hours before the measurement. Radon exposure risk was calculated using the radon dose and dose conversion factor. Indoor radon concentration, radon exposure risk, and annual effective dose were found within the 95% confidence interval as the minimum and maximum boundary ranges. The radon concentration in the lecture room was $43.1-79.1Bq/m^3$, and the maximum boundary range within the 95% confidence interval was $77.7Bq/m^3$. The annual effective dose was estimated to be 0.20-0.36 mSv/y (mean 0.28 mSv/y). The life-time effective dose was estimated to be 0.66-1.18 mSv (mean $0.93{\pm}0.08mSv$). Life effective doses were estimated to be 0.88-0.99 mSv and radon exposure risk was estimated to be 12.4 out of 10.9 per 100,000. Radon concentration was measured, dose effective dose was evaluated using dose conversion convention, and degree of health hazard by indoor radon exposure was evaluated by predicting radon exposure risk using nominal hazard coefficient. It was concluded that indoor living environment could be applied to other specific exposure situations.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.2
• /
• pp.474-483
• /
• 2004

To know the effects between Cd inhalation toxicity and extract of Radix Achyranthis Bidentatae, 4 rat groups were exposed to Cd aerosol in air using whole-body inhalation exposure for 6 hours/day, 5 days/week, and 4 weeks. Cd concentration in air was 1.03㎎/㎥ and mass median diameter(MMD) was 1.69㎛. 3 different dose intraperitoneal injections of extract of Radix Achyranthis Bidentatae to 3 inhalation exposure groups was done for 4 weeks and the results were as follows: The highest body weight gain for 4 weeks and food intake per day were from inhalation exposure group I and the highest lung and liver weight were also from inhalation exposure group I. The highest kidney weight was from inhalation exposure group III. The lowest Cd content in lung was 33.49㎍/g from inhalation exposure group I. The lowest Cd concentration in blood was 9.36㎍/㎗ from inhalation exposure control. Cd concentrations of 40.02㎍/g in liver and 69.18㎍/g in kidney were the lowest from inhalation exposure group I and III, respectively. The lowest Cd concentration in liver was 21.08㎍/g from inhalation exposure group III and The lowest Cd concentration in kidney was 15.78㎍/g from inhalation exposure group II. For weekly Cd concentration in urine, the value of the fourth week from inhalation exposure group III was the highest. For weekly Cd concentration in feces, the value of the first week from inhalation exposure group III was the highest. The highest metallothionein concentration in lung was 53.42 ㎍/g from inhalation exposure group III and the highest metallothionein concentration in liver was 188.18㎍/g from inhalation exposure group III. The highest metallothionein concentration in kidney was 143.92㎍/g from inhalation exposure group III. The highest Hct, Hb, and WBC values were from inhalation exposure group II and the highest RBC value was from inhalation exposure group III.

• Journal of Embryo Transfer
• /
• v.11 no.3
• /
• pp.225-231
• /
• 1996

This study was conducted to investigate the effects of preincubation time, concentration and exposure time of sperm on in vitro fertilization of porcine follicular oocytes rnatured in in vitro. The results obtained are as follows ; 1. Effect of preincuhation time for porcine sperm capacitation on in vitro fertilization in medium with heparin was investigated. Normal fertilization rate was highest in 15 min(26.4%). However, there were no significant differences among preincuhation times of 5~90 min, 2. Normal fertilization rates of sperm concentrations were 17.0~26.5%, and normal fertilization rate from l$\times$ l05cell /ml concentration was also higher than those of other sperm concentration. 3. Normal fertilization rates of sperm exposure time of 4, 8, 12, 16 and 20 hours were 6.1, 20.8, 27.8, 25.0 and 26.7%, respectively. Normal fertilization rate from sperm exposure time of 12 hours was also higher than that of other sperm exposure times.

• Toxicological Research
• /
• v.19 no.2
• /
• pp.99-104
• /
• 2003

This study was aimed to evaluate the effect of oxygen on motor activity and toxicity in male mice. The modified Porsolt forced swim test (FST) was used and the distance and time of movement by mice were analyzed in 15。C water bath for 20 minutes using the automatic Ethovision videotracking system. Analyses were carried out before and after 20 minutes of exposure to 10％-70％ concentration of normobaric oxygen. The effects of inspired oxygen tension on the distance and time of movement showed the similar trends, but changes in distance were more prominent. Both the distance and time of movement increased after exposure to 30％ and 40％ oxygen concentration. The distance and time of movement also increased upon exposure to 50％ and 60％ oxygen. In contrast, increases En movement and time under exposure to 21％ oxygen concentration were suppressed when exposed to over 50％ oxygen concentration. With exposure to 10％ oxygen, there was a significant decrease in the distance of movement and a slight suppression of movement time. During the swim test, 12.5％, 37.5％, and 87.5％ of the mice drowned after exposure to 10％, 60％, and 70％ oxygen concentration, respectively. These results suggest that motor activity can be enhanced by inspired oxygen up to 40％ concentration. When hypoxic and hyperoxic oxygen exposure over 50％, motor activity is reduced and toxicity may be induced.

• Journal of Environmental Health Sciences
• /
• v.28 no.2
• /
• pp.173-182
• /
• 2002

Exposure to environmental tobacco smoke(ETS) increases the risk of lung cancer and other diverse health effect for nonsmokers. Health risk assessment of nonsmokers related to ETS exposure requires large and exact data of ETS exposure to nonsmokers. This study presented the data of ETS exposure to workers at three category of restaurants(Korean restaurant, coffee shop, wine shop) in Seoul. Markers of ETS exposure measured in this study were area and personal NO$_2$, area and urine nicotine, area respiratory suspended particulate(RSP) and urine cotinine. The mean concentration of RSP and nicotine of all restaurant indoor samples was 177.8$\mu\textrm{g}$/㎥(range:75.3~317.0$\mu\textrm{g}$/㎥) and 7.8$\mu\textrm{g}$/㎥(range:0~57.3$\mu\textrm{g}$/㎥). The mean concentration of urine cotinine measured for the biomarker of ETS exposure was 77.3ng/mL(range:17.3~174.6ng/mL). In all measurements, the concentration of ETS markers at the wine shop was higher than those at other restaurants. The correlation coefficient among the ETS markers measured in the study was significant between area RSP and nicotine concentration and between area NO$_2$and nicotine concentration.

• Toxicological Research
• /
• v.26 no.2
• /
• pp.131-136
• /
• 2010

The time-dependent changes in cadmium (Cd) concentration were studied in Female Sprague-Dawley (SD) rats during and after Cd exposure via drinking water (10 and 50 ppm) for 30 days. The cadmium concentration in muscle, liver, kidney, blood plasma, and urine, and the metallothionein concentration in blood plasma were determined every 10 days during exposure and every 7 days after exposure for 3 weeks. The muscle Cd concentration did not change during, and neither after, exposure. The liver Cd concentration increased from 1.4 to 3.3 (at 10 ppm) and from 6.1 to 10.1 folds (at 50 ppm) during exposure and remained higher than those of controls in both groups even during post-exposure period. The kidney Cd concentrations were 2.3 to 5.1 (at 10 ppm) and 4.9-14.0 folds (at 50 ppm) higher than those of controls during exposure and also remained elevated during the post-exposure period. Plasma Cd concentrations were not significantly different from those of controls in both groups. Urine Cd concentrations were more than 2 folds (at 10 ppm) and 6.5 to 12.6 folds (at 50 ppm) higher than those of controls but rapidly decreased over the 7 days of withdrawal. Blood plasma metallothionein concentrations were more than 2.4 folds (at 10 ppm) and 3.1 to 7.4 folds (at 50 ppm), and they remained elevated till 7 days (10 ppm) and 14 days (at 50 ppm) after exposure. Our data support that Cd in urine could be a useful biomarker during Cd exposure period and metallothionein in blood plasma could be as a supportive biological marker for during and post Cd exposure.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.33 no.1
• /
• pp.3-5
• /
• 2023

Objective: This study introduces exposure concentrations of time-weighted average standard (TWA) evaluation and short-time exposure standard (STEL) evaluation for trichloroethylene in the cleaning process. Methods: Trichloroethylene measurement was conducted according to the KOSHA Guide (A-24-2019) method. It was carried out twice. Results: As a result of the first measurement, TWA concentration exceeded 4 times the exposure standard and STEL concentration exceeded 16 times, but the inaccuracy and breakthrough of the collection time could not be considered, so the second measurement was conducted. The second measurement result was lower than the first measurement result, but exceeded the exposure standards (TWA, STEL). Conclusions: We were able to confirm that the exposure level of workers in the cleaning process using trichloroethylene exceeded the exposure standard. And it is also considered necessary to grasp the approximate concentration using a detector tube in the preliminary survey.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.18 no.6
• /
• pp.1784-1794
• /
• 2004

To study the effects between Cd inhalation toxicity and methanol extract of Radix Achyranthis Bidentatae, 4 rat groups were exposed to Cd aerosol by whole-body inhalation exposure for 6 hours/day, 5 days/week, and 4 weeks. Cd concentration in air was 0.98㎎/㎥ and mass median diameter(MMD) was 1.78㎛. 3 different dose intraperitoneal injections of methanol extract of Radix Achyranthis Bidentatae to 3 inhalation exposure groups applied for 4 weeks and the results were as follows: The highest body weight gain for 4 weeks and food intake per day were from inhalation exposure group Ⅲ(p<0.05). The highest lung weight was from inhalation exposure group Ⅲ and the highest liver and kidney weight were from inhalation exposure group Ⅱ(p<0.05). The lowest Cd content in lung was 22.77㎍/g from inhalation exposure group Ⅲ(p<0.05). The highest Cd concentration in blood was 11.71㎍/㎗ from inhalation exposure group Ⅰ(p<0.05). Cd concentrations of 14.87㎍/g in liver and 17.91㎍/g in kidney were the highest from inhalation exposure group Ⅰ(p<0.05). The lowest Cd concentration in liver and kidney were 5.71㎍/g and 3.17㎍/g from the control(p<0.05). For weekly Cd concentration in urine, the highest value was 0.48㎍/㎖ from inhalation exposure group Ⅲ of the 3rd week and inhalation exposure group Ⅰ, Ⅱ of the 4th week. For weekly Cd concentration in feces, the highest value was 0.32㎍/g from inhalation exposure group Ⅰ, Ⅱ, Ⅲ. The highest metallothionein concentration in lung was 89.02㎍/g from inhalation exposure group Ⅲ(p<0.05). The highest metallothionein concentrations in liver and kidney were 265.47㎍/g and 214.21㎍/g from inhalation exposure group Ⅲ, respectively(p<0.05). The highest Hct, Hb, and WBC values were from inhalation exposure group Ⅱ and the highest RBC value was from inhalation exposure group Ⅲ(p<0.05). Mostly damaged part in liver tissue was hepatic lobule and the degrees of damage were lessened by the intraperitoneal injection of methanol extract of Radix Achyranthis Bidentatae. Proximal, distal convoluted tubules and glomerulus in kidney tissue were mostly damaged part. Degeneration and swelling were partially observed but the degrees of kidney tissue damage were lessened more or less by the intraperitoneal injection of methanol extract of Radix Achyranthis Bidentatae.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.6
• /
• pp.1243-1252
• /
• 2002

To experiment the effects between cadmium inhalation toxicity and extracts of Folium Mori, rat inhalation exposure groups were exposed to cadmium aerosol in air by whole-body inhalation exposure for 6 hours/day, 5 days/week, and 4 weeks. Cadmium concentration in the air of cadmium aerosol was 1.02㎎/㎥ and mass median diameter(MMD) was 1.40μm. Intraperitoneal injection of extracts of Folium Mori to inhalation exposure groups was done for 4 weeks and the results were as follows: The highest body weight gain for 4 weeks and food intake per day were 126.39g/4 weeks and 19.18g/day from inhalation exposure group III, respectively. The highest lung and liver weight were 1.27g and 8.19g from inhalation exposure group II, respectively. The highest kidney weight was 1.805g from inhalation exposure control. The lowest cadmium content in lung was 86.39μg/g from inhalation exposure group III. The lowest cadmium concentration in blood was 7.12㎍/㎗ from inhalation exposure group III. Cadmium concentrations of 40.02㎍/g in liver and 69.18㎍/g in kidney were the lowest from inhalation exposure group I and III, respectively. For weekly cadmium concentration in urine, the value of the fourth week from inhalation exposure group III was the highest, 3.12㎍/㎖. For weekly cadmium concentration in feces, the value of the fourth week from inhalation exposure group III was the highest, 2.67 ㎍/g. The highest metallothionein concentration in lung was 74.65㎍/g from inhalation exposure group III and the highest metallothionein concentration in liver was 386.84㎍/g from inhalation exposure group II. The highest metallothionein concentration in kidney was 236.17 ㎍/g from inhalation exposure group II.