• Title/Summary/Keyword: Cd Aerosol

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Design of Ultrasonic Nebulizer for Inhalation Toxicology Study of Cadmium with Application of Engineering Methodology and Performance Evaluation with Light-Scattering Photometer (공학적 기법을 응용한 카드뮴의 흡입독성 연구를 위한 초음파 네뷸라이져의 설계 그리고 광산란 광도계를 이용한 성능평가)

  • Jeung Jae Yeal;Milton Donald K.;Kim Tae Hyeung;Lee Jong Young;Chong Myoung Soo;Ko Kwang Jae;Kim Sang Duck;Kang Sung Ho;Song Young Sun;Lee Ki Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.3
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    • pp.464-471
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    • 2002
  • Author applied several engineering methodologies to classical ultrasonic nebulizer to cope with it's demerits. After several trials and errors, we got the several meaningful results. To evaluate the modified ultrasonic nebulizer for inhalation toxicology of cadmium, author used light-scattering photometer. This paper is the one part of inhalation exposure systems for inhalation toxicology study of cadmium. According to the testing conditions, source temperature 50℃ and inlet-duct band temperature 150℃, aerosol generation results for sodium chloride and cadmium chloride were as followings: Coefficients of variation(CV) of sodium chloride and cadmium chloride for repeated trials were 3.38 and 4.77 for 10g, 2.47 and 5.02 for 5g, and 4.70 and 2.98 for 2.5g. All the CVs were within 10% of acceptance variability. Count Per Minute(CPM) changes of NaCl and CdCl₂ for 5 repeated trials were similar. CPM ratios of CdCl₂/NaCl were 1.13 for 10g, 0.76 for 5g, and 1.06 for 2.5g. Relative aerosol generation of cadmium chloride to sodium chloride was the highest in 10g. Efficiency increases of 24.50% for 5g NaCl, 14.91 % for 2.5g NaCl, and 16.48% for 2.5g CdCl₂ with respect to theoretical efficiency were observed but 0.04% efficiency decrease was observed in 5g CdC₂. According to the modifications of source temperature(20, 50, 70℃) and inlet-duct band temperature(20, 50, 100, 150, 200℃), aerosol generation results for NaCl and CdCl₂ were as followings: CPM trends for each quantity excepting 10g NaCl in inlet-duct band temperature 200℃ were similar, and the highest CPM was observed in source temperature 70℃ to each inlet-duct band temperature. The highest CPMs to 10, 5, and 2.5g NaCl were observed in source temperature 70℃ and inlet-duct band temperature 20℃. Aerosol generation of cadmium chloride was increased with the higher source temperature, excepting inlet-duct band temperature 200℃. The highest CPMs for 10, 5, and 2.5g CdCl₂ were observed in source temperature 70℃ and inlet-duct band temperature 20℃, and this trend was similar to NaCl aerosol generation The highest CPMs for 10, 5, and 2.5g CdCl₂ were observed in source temperature 70℃ and inlet-duct band temperature 20℃, and this result was similar to NaCl aerosol generation. Observed efficiencies of 5 and 2.5g NaCl were similar to ifs theoretical efficiency but -3.08% efficiency decrease of 5g CdCl₂, 17.47% efficiency increase of 2.5g CdCl₂ were observed. CPM ratio of CdCl₂/NaCl of 10g was different to 5 and 2.5g, and 2.5g ratio was higher than 5g ratio. In conclusion, to get maximum aerosol generation for NaCl and CdCl₂ will be the conditions that set the appropriate inlet-duct band temperature for each materials and increase the source temperature. Sodium chloride can be used to evaluate the performance and predict the concentration for cadmium aerosol in aerosol generator and inhalation exposure system.

Effect of an Excipient on the Formation of PLGA Particles Using Supercritical Fluid (초임계 유체를 이용한 PLGA 입자 제조에 첨가제가 미치는 영향)

  • Jung, In-Il;Haam, Seung-Joo;Lim, Gio-Bin;Ryu, Jong-Hoon
    • Polymer(Korea)
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    • v.36 no.1
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    • pp.1-8
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    • 2012
  • In this study, we employed hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) as an excipient to produce poly(lactic-$co$-glycolic acid) (PLGA) fine particles by a supercritical fluid process, called aerosol solvent extraction system (ASES), and investigated the effect of HP-${\beta}$-CD content on the morphology of the particles. The influence of HP-${\beta}$-CD on the drug release characteristics of paclitaxel-loaded PLGA particles was also evaluated. Fine particles were obtained when the HP-${\beta}$-CD content in PLGA/HP-${\beta}$-CD mixtures was greater than 40% and 30%, respectively, for PLGA(75:25) and PLGA(50:50), whereas a film-like precipitate was obtained for lower HP-${\beta}$-CD content. The release rate for paclitaxel loaded PLGA(75:25)/HP-${\beta}$-CD particles was found to increase with HP-${\beta}$-CD content.

Utilization of Supercritical Carbon Dioxide for the Preparation of 2-Hydroxypropyl-β-Cyclodextrin Microparticles and Their Inclusion Complexes with Ibuprofen (초임계 이산화탄소를 이용한 2-Hydroxypropyl-β-Cyclodextrin 미립자와 이부프로펜과의 포접복합체 제조)

  • Ryu, Jong-Hoon
    • Clean Technology
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    • v.19 no.3
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    • pp.212-218
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    • 2013
  • The microparticles of 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) were prepared using aerosol solvent extraction system (ASES) by employing supercritical carbon dioxide as an antisolvent, The effects of various process parameters such as temperature, pressure, solution concentration and solution flow rate on the formation of HP-${\beta}$-CD microparticles were investigated. The HP-${\beta}$-CD microparticles prepared by the ASES process were observed to consist of agglomerates of nano-sized (50-200 nm) particles. When an aqueous solution of ethanol was used as a solvent for HP-${\beta}$-CD, the HP-${\beta}$-CD particles were found to be spherical in shape and to become larger as the water content increased. It was confirmed that the micronization of HP-${\beta}$-CD using the ASES process could enhance the inclusion efficiency of ibuprofen/HP-${\beta}$-CD complexes significantly.

Determination of Cadmium and Zinc Contamination Source in Arable Soil in the Vicinity of a Zinc Smelting Factory

  • Hong, Chang-Oh;Gutierrez, Jessie;Lee, Seul-Bi;Lee, Yong-Bok;Yu, Chan;Kim, Pil-Joo
    • Korean Journal of Environmental Agriculture
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    • v.26 no.3
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    • pp.204-209
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    • 2007
  • Agricultural area in the vicinity of the ${\triangle}{\triangle}$ smelting factory in Kyeongbuk province, the third largest zinc smelting factory in the world, was contaminated by high concentration of heavy metals. However, the heavy metals source was not yet directly traced and thus, resulted to a conflict between the factory and residents within its vicinity. In order to determine the level of heavy metal contamination in the arable lands located at the north eastern part of the factory, soils were sampled systematically. To find out the major reason for the occurrence of this problem, waters and aerosols were sampled with constant intervals to the upward and downward direction from the factory and were analyzed to find out the heavy metal concentrations. Cadmium (Cd) and zinc (Zn) of the heavy metals were highly accumulated more than the Korean warning criteria (Cd 1.5, Zn 300 mg $kg^{-1}$) with mean values 1.7 and 407 mg $kg^{-1}$, respectively, at the surface soils (0-20 cm), and heavy metal concentration significantly decreased with increasing soil depth In addition, the concentration of both metals slightly decreased with increasing distance from the factory to the surface soils. Cadmium and Zn were detected in the upward stream water with low concentration and concentrations increased significantly in the downstream after passing across the factory. Aerosol samples also showed traces of Cd and Zn which could be attributed to the contamination of the water system and the surface soils. Conclusively, Cd and Zn emitted from the ${\triangle}{\triangle}$ smelting factory moved with the aerosol in the atmosphere and thus, contaminated the agricultural areas and the water system within it vicinity.

Emission Characteristics of Elemental Constituents in Fine Particulate Matter Using a Semi-continuous Measurement System (준 실시간 측정시스템을 이용한 미세입자 원소성분 배출특성 조사)

  • Park, Seung-Shik;Ondov, John M.
    • Journal of Korean Society for Atmospheric Environment
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    • v.26 no.2
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    • pp.190-201
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    • 2010
  • Fine particulate matter < $1.8{\mu}m$ was collected as a slurry using the Semicontinuous Elements in Aerosol Sampler with time resolution of 30-min between May 23 and 27, 2002 at the Sydney Supersite, Florida, USA. Concentrations of 11 elements, i.e., Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn, in the collected slurry samples were determined off-line by simultaneous multi-element graphite furnace atomic absorption spectrometry. Temporal profiles of $SO_2$ and elemental concentrations combined with meteorological parameters such as wind direction and wind speed indicate that some transient events in their concentrations are highly correlated with the periods when the plume from an animal feed supplement processing facility influenced the Sydney sampling site. The peaking concentrations of the elemental species during the transient events varied clearly as the plume intensity varied, but the relative concentrations for As, Cr, Pb, and Zn with respect to Cd showed almost consistent values. During the transient events, metal concentrations increased by factors of >10~100 due to the influence of consistent plumes from an individual stationary source. Also the multi-variate air dispersion receptor model, which was previously developed by Park et al. (2005), was applied to ambient $SO_2$ and 8 elements (Al, As, Cd, Cr, Cu, Fe, Pb, and Zn) measurements between 20:00 May 23 and 09:30 May 24 when winds blew from between 70 and $85^{\circ}$, in which animal feed processing plant is situated, to determine emission and ambient source contributions rates of $SO_2$ and elements from one animal feed processing plant. Agreement between observed and predicted $SO_2$ concentrations was excellent (R of 0.99; and their ratio, $1.09{\pm}0.35$) when one emission source was used in the model. Average ratios of observed and predicted concentrations for As, Cd, Cr, Pb, and Zn varied from $0.83{\pm}0.26$ for Pb to $1.12{\pm}0.53$ for Cd.

Effects of Extract of Radix Achyranthis Bidentatae on Cadmium Inhalation Toxicity in Rats (우슬 추출물이 카드뮴 흡입폭로된 흰쥐의 독성해독에 미치는 영향)

  • Kim Hong Ki;Jeung Jaeyeal;Park Seung Jong;Kang Sung Ho;Song Young Sun;Lee Ki-Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.2
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    • pp.474-483
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    • 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.

The Formation of Absorption Layer for the CIGS Solar Cell by Aerosol Deposition Method (Aerosol Deposition 법을 이용한 CIGS 태양전지의 광흡수층 형성)

  • Kim, In Ae;Shin, Hyo Soon;Yeo, Dong Hun;Jeong, Dae Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.12
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    • pp.909-914
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    • 2013
  • CIGS is one of thin film solar cell and has been studied so much, because of the possibility of low price and high efficiency. Until now, co-evaporation and sputtering were typical method to prepare CIGS absorption layer, and a few company commercialized solar cell by these method. However, non-vacuum process which has been studied for long time has not been progressed, though the merit of low price. Especially, aerosol deposition method has not been reported, because it is difficult to prepare a large quantity of various CIGS powder. In this study, CIGS powder was synthesized by mechanochemical method and CIGS absorption layer was deposited by aerosol deposition method. The thickness of the CIGS layer was controlled by the number of deposition and the surface roughness of it was affected by the amount of flow gas. And, also, I-V curve of it appeared metallic property in the case of 'as deposition'. After heat treatment in Se-rich atmosphere, the electrical property of it changed to a semiconductor. CdS and transparent conduction layer were formed by a typical method on it for solar cell. The efficiency of cell was appeared 0.19%. Though the efficiency was low because of the disharmony in the after-process, it was conformed that CIGS solar cell could be prepared by aerosol deposition.

Particle Size of Aerosol from 0.25% Cadmium Chloride Nebulizing Solution for Inhalation Toxicology Study (흡입독성 연구에 이용될 0.25% 염화카드뮴 네뷸라이징 용액 에어로졸의 입경)

  • Jeung Jae Yeal;Lee Ki Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1257-1263
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    • 2003
  • The modified engineering methodology and the modified electronic circuit in classical ultrasonic principles were applied to ultrasonic aerosol nebulizer for inhalation toxicology study of cadmium aerosol. 1532.96ppm Cd nebulizing solution was used to generate cadmium aerosol for particle size analysis with the modifying source and inlet temperatures. The results of particle size analysis for cadmium aerosol were as following. The highest particle counting for source temperature 20℃ was 399.75 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 50℃ was 399.70 × 10² in inlet temperature 50℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 70℃ was 411.14 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The ranges of geometric mean diameter were 0.74-0.79㎛ in source temperature 20℃, 0.65-0.72㎛ in source temperature 50℃, and 0.65-0.80㎛ in source temperature 70℃. The smallest geometric mean diameter was 0.65㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest geometric mean diameter was 0.80㎛ in source temperature 70℃ and inlet temperature 100℃. The ranges of geometric standard deviation were 1.71-1.80 in source temperature 20℃, 1.27-1.61 in source temperature 50℃, and 1.27-2.29 in source temperature 70℃. The lowest geometric standard deviation was 1.27 in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the highest geometric standard deviation was 2.29 in source temperature 70℃ and inlet temperature 100℃. Generated aerosol for cadmium inhalation toxicology study was polydisperse aerosol with the above geometric standard deviation 1.2. The ranges of mass median diameter(MMD) were 1.75-2.25㎛ in source temperature 20℃, 1.27-1.61㎛ in source temperature 50℃, and 1.27-2.29㎛ in source temperature 70℃. The smallest MMD was 1.27㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest MMD was 2.29㎛ in source temperature 70℃ and inlet temperature 100℃. Cadmium chloride concentration in nebulizing solution affected the particle size and distribution of cadium aerosol in air. MMO for inhalation toxicology testing in OECD and EU is less than 3㎛ and EPA guidance is less than 4㎛. In our results, in source temperatures of 20, 50, 70℃, and inlet temperatures of 20, 50, 100, 150, 200, 250℃ were conformed to the those guidance.

Chemical characteristics of atmospheric particulate species in Mt. Soback, Korea(II):The sources and seasonal variations of metallic elements (소백산 대기 중 입자상 물질의 화학적 특성에 관한 연구(II):금속 원소의 계절적인 변화와 기원을 중심으로)

  • 최만식;이선기;최재천;이민영
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.2
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    • pp.191-198
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    • 1995
  • In order to evaluate the distribution and behaviour of atmospheric particulate metals in high-altitude area, we collected 22 aerosol samples using a high volume air sampler at Soback Mt. Meteorological Observation Station from Jan. to Nov. 1993 and analysed for metals (Al, Fe, Mg, Na, Ca, Mn, Co, Ni, Cu, Zn, Cd, and Pb) with ICP/AES and ICP/MS. Although sampling site is located in high-altitude and far from local sources of atmospheric pollutants, enrichments of metals are 2 times higher than those of western coastal reural area. This fact may imply that of metallic pollutants in the coastal rural site were came from further western side (e.g. China), atmospheric metals in this study area contain the signal of metropolitan cities located in the main wind direction (NNW). Sea salts are negligible in the aerosol particle population because reference elements of sea salts (Na, Mg) are all originated from soil particles. The contents of soil particles in aerosols are highest in spring and lowest in winter. Atmospheric enriched elements (Ni, Cu, Zn, Cd and Pb) are diluted with soil particles, especially during the yellow sand period. The results of factor analysis suggest possibility of interpreting their chemical significance in terms of sources (soil, pollutants) and gas-particle conversion processes (formation of ammonium sulfates, ammonium nitrates and/or their mixtures).

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Aerosol Sampling with Two Stage Filter Sampler and Seasonal Variation of Metal Components in the Atmosphere (이단 필터 샘플러에 의한 대기 부유분진의 포집 및 금속 성분의 계절별 거동에 관한 연구)

  • Lee, Yong-Keun;Kim, Nam-Hoon;Myung, No-Seung;Whang, Kyu-Ja
    • Journal of Korean Society for Atmospheric Environment
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    • v.4 no.2
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    • pp.20-27
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    • 1988
  • A simple two stage aerosol filter sampler which allows simultaneous and fractional collection of two different-size particles, coarse and fine, was constructed and applied to the collection of Seoul atmospheric particulate for inorganic analysis. The sampler consist of two 47-mm diameter filter holder, a pneumatic pump, and a flowmeter. Filtering rate normally runs around 20$\ell$/min for 8 hrs. Using the sampler, a series of seasonal aerosol samples were collected from June 1986 to March 1988 at Yonsei University campus, Seoul and subsequently analysed for ten environmentally important metals using an atomic absorption spectrometer and an inductively coupled plasma emission spectrometer. The analysed metals are Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn. The analytical results showed the following order of metal abundance; Al > Fe > Zn > Pb > Mn > Cu > V > Ni > Cr > Cd. Based upon their size distribution pattern, the analyzed matals could be clasified into two groups, those present primarily in coarse particle and those in fine particle. Fe, Al, Mn, V, and Cr belong to the former group while the rest to the latter. Most metal concentration were highest in spring or winter, and lowest in autumn. Statistical analysis showed strong correlations between Al and Fe, Pb and Zn, and Cu and Mn.

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