• 제목/요약/키워드: Exposure Concentration

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산꼬리풀의 효과적인 육묘를 위한 재배조건 최적화 (Optimization of Cultivation Conditions on Effective Seedlings of Veronica rotunda var. subintegra (Nakai) T.Yamaz.)

  • 이상인;연수호;조주성;정미진;이철희
    • 생물환경조절학회지
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    • 제29권2호
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    • pp.181-188
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    • 2020
  • 본 연구는 국내 특산식물이며 관상소재로 개발이 가능한 산꼬리풀의 효과적인 육묘조건을 구명하기 위해 수행되었다. 육묘는 토양 종류와 비료 농도, 차광정도, 추비 농도, 종자의 광원 전처리 및 채종 시기별로 각 요인을 달리하여 수행하였다. 연구 결과, 산꼬리풀은 원예상토에서 생육이 우수하였으며, 혼용토에서는 비료 첨가 시 생육이 억제되었다. 차광은 55% 차광조건에서 무차광에 비해 전체적인 생육이 향상되었다. 고농도(1000mg·L-1)의 Hyponex는 육묘 시 생육을 촉진하였으며, 파종 전 종자에 대한 적색광 조사는 추후 초장과 생체중 향상에 효과적이었다. 채종 시기는 2018년도 종자가 2017년 종자보다 생육이 우수하였다.

수확, 경운정지, 파종, 정식, 순지르기 작업에서 발생하는 PM10 노출 특성 (PM10 Exposure Characteristics During the Harvesting, Plowing, Sowing, Planting, and Decapitation Tasks of Agricultural Workplaces in South Korea)

  • 정원건;서민태;김효철
    • 한국산업보건학회지
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    • 제32권2호
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    • pp.137-145
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    • 2022
  • Objectives: This study aimed to identify PM10 mass concentration levels and conduct peak identification during five tasks in agricultural works. Methods: We investigated five agricultural tasks in 12 farms, which were harvesting, plowing, sowing, planting, and decapitation. All samples were measured by using the portable aerosol spectrometer(PAS 1.108) and the aerosol monitor(SidePak AM520). The collected data were compared with the national PM10 concentrations. They were calculated to descriptive statistics, independent t-test, or ANOVA, and the peak identification on time series graph. Results: The ten investigated farms showed no significant difference with the national PM10 concentrations, but the two greenhouses(AM, 143.31, 85.16 ㎍/m3) showed significant difference(p<0.05). As a result of the peak identification, the harvesting tasks showed repeated peak occurrence with the background concentration level of about 50 ㎍/m3. For plowing and sowing tasks, the peak occurred intermittently when the working was conducted near the sampling sites. Among the five tasks, the arithmetic mean of the harvesting task was 138.84±294.71 ㎍/m3, which was significantly higher than the other tasks(p<0.05). In addition, the case of using a tractor was higher than the case of not using the tractor(p<0.05), and the driver's seat showed the highest concentration(AM, 95.81 ㎍/m3). Conclusions: Works in greenhouses might have exposure to PM10, while outdoor works is similar to general atmospheric PM10 concentration levels. However, there is a possibility of intermittent exposure to high concentrations of PM10 depending on the characteristics of agricultural tasks.

Effect of Carbon Dioxide Concentration on Malate and Titratable Acidity in Pereskia aculeata and Kalanchoe rosea

  • Park Shin Young;Furukawa Akio
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제2권2호
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    • pp.109-114
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    • 1998
  • The induction of crassulacean acid metabolism(CAM) characterized by day/night acid fluctuation was investigated in leaves from 10 days exposure to elevated $CO_2$ concentration(1,000 ${\mu}L\;L^{-1}CO_2).$ For Pereskia aculeata, have $C_3-like$ gas exchange pattern in well watered condition and shift into CAM-like in water stress, showed a more typical CAM-like diurnal acid fluctuation. Whereas the massive diurnal fluctuation of acidity in typical CAM of Kalanchoe rosea was declined. The effect of short-term exposure to various concentrations of $CO_2$ on titratable acidity in P. aculeata and K. rosea was also investigated. To investigate the response of various $CO_2$ concentrations, four different $CO_2$ levels(350, 700, 1,000 and 1,500 ${\mu}L\;L^{-1})$ were imposed for 24hr and measured the titratable acidity at 06:00, when the acidity was maximum, and 14:00, when the acidity was minimum. The accumulation of acid in P. aculeata was enhanced markedly by higher concentration of $CO_2,$ while the level of acidity in f rosea did not highly respond to $CO_2.$ A notable difference between P. aculeata and K. rosea was the response of de-acidification to a higher concentration of $CO_2$ Increasing with $CO_2,$ the degree of do-acidification of P. auleata was increased while that of K. rosea was depressed.

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소주 및 맥주 음주와 혈중 수은과의 관계에 관한 연구 (Association between Blood Mercury and Drinking Soju and Beer in Korea)

  • 조준호
    • 한국환경보건학회지
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    • 제44권4호
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    • pp.348-359
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    • 2018
  • Objectives: The purpose of this study was to investigate the relationship between frequency of alcohol drinking and blood mercury concentration in Korea. Methods: This was a cross-sectional study that used data from the Korean National Health and Nutrition Examination Survey. Among them, 3,174 persons were selected for the final study. Results: The concentration of mercury in the blood increased as the frequency of drinking soju or beer increased. Similarly, in the multiple-linear regression analysis model, the frequency of soju drinking was identified as an independent variable showing a statistically significant positive linearity (p<0.001). After controlling for confounding factors, comparing those drinking 'more than twice a week' with those who almost do not drink alcohol, the adjusted ORs for exposure to high concentrations of mercury were 3.24 (95% CI, 2.10-4.99) for drinking soju and 2.07 (95% CI, 1.33-3.22) for drinking beer. The interaction effect between 'soju drinking' and 'spicy pollack and seafood stew' was not statistically significant (p=0.098) for evaluating the interaction effect between the two variables. Conclusions: The concentration of mercury in the blood increased as the frequency of drinking of soju or beer increased. The higher the frequency of alcohol drinking, the more likely is the blood mercury to be included in the high-concentration group. The results of this study can be used as important scientific evidence for the field of environmental health related to alcohol drinking and blood heavy metal exposure in Korea.

Effects of Ammonia Concentration on Histological and Physiological Status in Black Seabream (Acanthopagrus schlegeli)

  • KWON Joon Yeong;CHANG Young Jin
    • 한국수산과학회지
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    • 제29권6호
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    • pp.828-836
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    • 1996
  • The histological changes of gill, liver, spleen and muscle, and respiration and blood variables and liver glycogen content were examined in black seabream, Acanthopagrus schlegeli. Fish were exposed to a high level of total ammonia nitrogen (10.4 mg/l) and recovered from exposure $(0.4{\pm}0.2mg/l)$ in a closed recirculating seawater system. In the process of exposure, mortality was $9\%$, and hyperplasia, necrosis or inflammation appeared in all tissues except for muscle. Oxygen consumption was decreased by $49\%$, and red blood cell (RBC) number, hematocrit and hemoglobin concentration were significantly decreased, while plasma glucose contents, activities of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) increased. Liver glycogen content significantly increased from $6.6\%\;to\;10.4\%$. A large amount of hemosiderin was observed in the splenic tissue. During the recovery period, RBC number, hematocrit, hemoglobin concentration, GOT and GPT activities were returned to the normal status. Histological status of liver tissue was returned to the normal, but liver glycogen content was not recovered. During the recovery period, spleen melanin-macrophages temporarily increased, but subsequently decreased to the normal status.

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PC방에서의 간접흡연에 따른 요중 코티닌의 농도 (Urinary cotinine concentration by passive smoking in the PC game room)

  • 박용선;노영만;김치년
    • 한국환경보건학회지
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    • 제28권1호
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    • pp.11-20
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    • 2002
  • Tobacco smoke was confirmed as a human carcinogen by many research results. Because many adolescents stay long time in the PC game room, they are exposed to much of tobacco smoke. To evaluate the effect of passive smoking in the PC game room, airborne nicotine concentrations in 2 PC game rooms in Sung-nam city and urinary cotinine concentrations were measured for 20 adolescents. And the subjects were interviewed for duration and time in PC game room and smoking pattern. Subjects are composed of each of 10 smokers(5 males and 5 females) and 10 nonsmokers(5 males and 5 females). They stayed for three hours in the PC game room without smoking. Concentrations of nicotine in smokers and nonsmokers were 129.72 $\mu$g/$^3$ and 99.99 $\mu$g/m$^3$, respectively. Urinary cotinine concentrations were increased as time goes on after exposure to nicotine and showed maximum value at 9.45 hours after nicotine exposure and were 32.21 and 110.66 $\mu$g/L for nonsmoker and smokers. The more using time and frequency in PC game room, the higher urinary cotinine maximum concentration and the longer using duration, also the more increase urinary cotinine concentration. Urinary cotinine has a tendency to increase by passive smoking. Therefore, it is recommended that the effective control for indoor air quality and extensive research be needed to reduce nicotine concentration by passive smoking in the PC game room.

Green Tobacco Sickness Among Tobacco Harvesters in a Korean Village

  • Park, Sung-Jun;Lim, Hyun-Sul;Lee, Kwan;Yoo, Seok-Ju
    • Safety and Health at Work
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    • 제9권1호
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    • pp.71-74
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    • 2018
  • Background: Green tobacco sickness (GTS), an occupational disease in tobacco harvesters, is a form of acute nicotine intoxication by nicotine absorption through the skin from the wet green tobacco plant. We carried out a questionnaire survey and measured cotinine concentration, the metabolic product of nicotine, to determine the prevalence, incidence, and risk factors of GTS in Korean tobacco harvesters. Methods: We measured cotinine concentrations, and administered a questionnaire survey to tobacco harvesters in Cheongsong-gun, Gyeongsangbuk-do, Korea. We repeatedly measured urine cotinine concentration five times with a questionnaire survey. Results: Cotinine concentration at dawn was significantly higher than that at other times; it was significantly lower during the nonharvesting period than during the harvesting period. However, little change in cotinine concentration was detected in the daytime during the harvesting period. Study participants included 20 men and 20 women. The prevalence of GTS was 37.5% and was significantly higher in women than in men (55.0% vs. 20.0%, p < 0.01). GTS incidence according to number of workdays was 3.4 occurrences/100 person days. Conclusion: In this study, nicotine exposure and metabolism were experimentally determined from the time of cotinine exposure, and biological monitoring was performed in each season. In the future, this information may be valuable for medical decision-making in GTS prevention.

아질산 노출이 흰다리새우, Litopenaeus vannamei의 생존율 및 독성 생리에 미치는 영향 (Effects of nitrite exposure on survival and physiology of white leg shrimp, Litopenaeus vannamei)

  • 김수경;김석렬
    • 한국어병학회지
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    • 제36권2호
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    • pp.361-368
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    • 2023
  • Juveniles of the white leg shrimp Litopenaeus vannamei (Weight 0.18±0.08 g) were exposed to nitrite-N at 0, 25, 50, 100, 200 and 400 mg/L for 72 hours, and the lethal concentration, heamolymph and genes regulation were evaluated. The lethal concentration 50 (LC50) of L. vannamei exposed to nitrite-N was 141.2 mg/L at 25℃ and 33 psu. In Total protein, total cholesterol, and BUN in heamolymph temporarily increased after the start of the experiment and then stabilized, but glucose, an indicator of stress, decreased over time in the entire experimental group, and creatines, an indicator of tissue damage, decreased with nitrite concentration until the first 12 hours. The genes of immune-related showed that masquerade-like serine proteinase(Mas) increased at 50 and 400 ppm for 24 hours, and then gradually decreased depending on concentration. In the case of prophenoloxidase, it was highest at 400 ppm for 40 hours, and other genes(Ras-related nuclear protein, Masquerade-like serine proteinase, proPO-activating enzyme) showed a response for 48 hours and then gradually decreased. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of L. vannamei.

카드뮴과 아연 노출에 따른 야외종 장수깔따구(Chironomus plumosus)의 생태독성학적 반응 (Ecotoxicological Response of Cd and Zn Exposure to a Field Dominant Species, Chironomus plumosus)

  • 김원석;홍철;박기연;곽인실
    • 생태와환경
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    • 제52권3호
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    • pp.266-273
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    • 2019
  • 인간의 인위적 활동으로 인해 발생하는 중금속 중 카드뮴(Cd)과 아연(Zn)은 다양한 경로를 통해 하천으로 유입되어 서식생물에게 유해 영향을 준다. 본 연구에서는 도심 하천에서 우점하는 장수깔따구 (Chironomus plumosus)를 이용하여 Cd와 Zn 노출에 따른 생태독성학적 반응을 연구하였다. 생활사를 고려하여, 생존율, 성장율, 우화율, 성비와 하순기절 기형을 관찰하였다. 장수깔따구 생존율은 Cd와 Zn 노출에 따라 시간, 농도의존적인 경향을 나타냈다. 성장율은 Cd 노출 후 Day 4와 Day 7, 농도의존적인 감소를 보였으며, 고농도인 $50mg\;L^{-1}$에서 대조군에 비해 급격한 감소를 나타냈다. 또한, 우화율은 10, $50mg\;L^{-1}$ Cd에서 대조군에 비해 감소함을 관찰하였다. 성비 변화는 $100mg\;L^{-1}$ Zn에서 암컷의 비율이 증가였으나 농도가 높아짐에 따라 수컷의 비율이 높아짐을 보이며 성비불균형이 관찰되었다. 게다가, 장수깔따구의 하순기절에서는 대조군에 비해 Cd와 Zn 노출된 장수깔따구에서 기형이 관찰되었다. 이와 같은 결과는 수생태계로 유입되는 중금속이 하천의 하상저층에 서식하는 저서무척추동물에게 유해한 영향을 주며, 중금속 노출에 따른 생물학적 분석을 위한 현장 지표종으로서의 가능성을 보여주었다.

곰팡이 노출에 따른 건강영향 및 민감 시설 내 곰팡이 분포 현황 (Health Effects of Exposure to Indoor Mold and the Levels of Mold in Facilities with Susceptible Populations in Korea)

  • 서성철
    • 한국환경보건학회지
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    • 제46권4호
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    • pp.359-367
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    • 2020
  • Objectives: Exposure to mold is strongly associated with adverse health effects (development or exacerbation of allergic diseases). We reviewed the health effects of mold exposure and explored to determine the annual distribution of indoor mold in facilities with susceptible populations. Methods: The health effects of mold exposure were mainly summarized by reviewing related papers and WHO research reports. We selected 10 facilities, including daycare centers, postpartum care centers, medical institutions, and elderly care facilities within the Seoul Metropolitan. Mold sampling was performed once every week or once every quarter from February 2016 to 2017. In addition, fungal species analyses was performed, and distribution status by month and facility was analyzed in the same manner as concentration. Results: Adverse health effects attributed to fungal exposure are largely divided into allergic symptoms, toxic effects, and infectious effects. Monthly mean concentrations of mold indoors and outdoors was 368.8 CFU/㎥ (geometric mean 213.4 CFU/㎥) and 496.0 CFU/㎥ (327.9 CFU/㎥), respectively. The indoor concentration has begun to increase in February, peaked in July, declined in August, increased again until October, and then decreased in November. About 36 genera of indoor fungal species were found in each facility. Cladosporium sp., Penicillium sp., Fusarium sp., Aspergillus sp., Alternaria sp., and Arthrinium sp. were observed as the dominant species. Conclusions: Our findings showed that the overall level of indoor mold was below the 500 CFU/㎥ level recommended by the Ministry of Environment. The development of DNA-based assessment and expanding facilities to be monitored for mold would be necessary for preventive aspects.