• Title/Summary/Keyword: Geometric Mean

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BACTERIOLOGICAL STUDIES ON MAEKET SEA FOODS 3. Sanitary indicative bacteria in frozen sea foods (시판 수산식품에 대한 세균학적연구 3. 냉동식품의 위생지표세균에 관하여)

  • CHANG Dong-Suck;CHOE Wi-Kyung;CHO Kwon-Ok
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.3
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    • pp.157-165
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    • 1975
  • This experiment was carried out to evaluate the sanitary quality of commercially frozen sea foods. One hundred and sixteen samples in six different items from several refrigeration plant in Busan city were examined from March to December in 1974. In addition, the changes in bacterial density through the process from thawing, round or semifilleted frozen alaska pollack to the finishing as frozen fillet blocks were observed. To evaluate the sanitary quality, sanitary indicative bacteria such as total coliform, fecal coliform, fecal streptococci and enterococci as well as plate counts were determined. From the results, the median value of fecal coliform MPN was 20 per 100 grams of the samples and that of enterococci was 790. The median value of plate counts was $2.2\times10^4$ per gram. The plate counts were not correlated with the number of sanitary indicative bacteria. The results suggest that enterococci could be used advantageously in preference to coliform organisms as indicative bacteria for the evaluation of sanitary quality of frozen sea foods. The plate counts at $20^{\circ}C$ of the samples were 14 times higher than that at $35^{\circ}C$. Geometric mean of total coliform MPN was 310 and that of enterococci was 143. Bacterial density was reduced by fleering. Morethan 50 percent for total coliform MPN and $35^{\circ}C$ plate counts, and about 35 percent for enterococci MPN and $20^{\circ}C$ plate counts were reduced under the contact freezing unit which was generally operated at $-40^{\circ}C$. About fifty-five percent of the samples were negative in fecal coliform test and 10 percent of those were exceeded $1.0\times10^5$ per gram in $35^{\circ}C$ plate counts.

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Methacholine and adenosine 5'-monophosphate challenge tests in children with atopic asthma and with nonatopic asthma, and their relationships to blood eosinophil markers. (아토피성 천식 환아와 비아토피성 천식 환아에서 메타콜린과 아데노신 기관지 유발 검사의 비교 및 혈중 호산구 염증 지표와의 관련성)

  • Lee, Sun Hee;Kim, Do Kyun;Choi, Sun Hee;Koh, Young Yull
    • Clinical and Experimental Pediatrics
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    • v.49 no.11
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    • pp.1216-1222
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    • 2006
  • Purpose : Though atopic and nonatopic asthma have different clinical manifestations, bronchial hyperresponsiveness (BHR) and airway inflammations are common characteristics of them. We investigated BHR to both methacholine and adenosine 5'-monophosphate (AMP), and their relationships with blood eosinophil markers in nonatopic asthma as well as atopic asthma. Methods : We studied 116 children (82 atopics; 34 nonatopics) with mild to moderate asthma. Methacholine and AMP challenge tests were performed and bronchial responsiveness was expressed as $PC_{20}$ (provocative concentration causing a 20 percent fall in $FEV_1$); blood eosinopil counts (ETCs) and serum eosinophil cationic protein (ECP) levels were gauged. Results : In atopics, 95.1 percent and 90.2 percent showed hyperreactivity to methacholine ($PC_{20}$<16 mg/mL) and AMP ($PC_{20}$<200 mg/mL), respectively. Meanwhile, in nonatopics, 94.1 percent and 52.9 percent displayed hyperreactivity to methacholine and AMP, respectively. The geometric mean of AMP $PC_{20}$ was lower in atopics (31.6 mg/mL) than in nonatopics (125.9 mg/mL); that of methacholine $PC_{20}$ was similar in the two groups. AMP $PC_{20}$ correlated with blood ETCs in both atopics(r=-0.30, P<0.01) and nonatopics (r=-0.57, P<0.01), and correlated with serum ECP levels (r=-0.23, P<0.01) in atopics, but not in nonatopics. Apart from AMP, methacholine $PC_{20}$ was not associated with blood eosinophil markers in either group. Conclusion : Atopics more frequently displayed BHR to AMP than nonatopics. Furthermore, BHR to AMP was associated with not only blood ETCs, but serum ECP levels in atopics but was correlated with only blood ETCs in nonatopics. Those results suggest that BHR to AMP reflects airway inflammation in asthma and is more related to atopy.

Bacteriological Quality of Sea Water at Swimming Beaches in Busan Area (부산시내 해수욕장해수의 세균학적 수질에 관한 연구)

  • KIM Yong-Kwan;CHANG Dong-Suck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.3
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    • pp.148-157
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    • 1981
  • This experiment was carried out to evaluate the sanitary quality of sea water at popular swimming beaches such as Haeundae, Kwanganri and Songjeong which are located in the suburbs of Busan Korea. One hundred and seventy five sea water samples were collected from the 25 stations during the both summer seasons in 1979 and in 1980. The sampling stations were established in the above 3 swimming beaches and the estuary of Suyeong river (See Fig.1.). To evaluate the sanitary quality, coliform group, fecal coliform, viable cell count and Vibrio parahaemolyticus were observed. The median value of coliform group MPN of the samples ranged 2,300 to 6,500/100m1 in Kwanganri, 670 to 910/100m1 in Haeundae and 430 to 460/100m1 in Songjeong swimming beach. Geometric mean of fecal coliform MPN was 3,200/100m1 in Kwanganri, 500/100m1 in Haeundae and 360/100m1 in Songjeong swimming beach. Composition of coliform was $23\%$ Escheri-chia coli group, $20\%$ Citrobacter freundii group, $41\%$ Klebsiella aerogenes group and $16\%$others. The density of Vibrio parahaemolyticus in Kwanganri was much higher than those of in other beaches by 5 to 6 times. Plate count of the samples in the estuary of Suyeong river was varied from 300 to $8.5\times10^6/ml$ during the study period. No remarkable difference was observed in bacterial density by tide in swimming beaches but the bacterial density of sea water at ebb tide was obviously higher than those of the samples at flood tide in the estuary of Suyeong river.

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Antibody persistence after Haemophilus influenzae type b (Hib) primary vaccination and response to boosters in Korean children (한국 소아에서 Haemophilus influenzae type b (Hib) 기초 예방 접종 후 항체 지속과 추가 접종에 대한 반응)

  • Lee, Hyunju;Park, So Eun;Lim, Soo Young;Choi, Kyong Min;Lee, Hoan Jong;Kim, Kyung Hyo
    • Clinical and Experimental Pediatrics
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    • v.50 no.5
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    • pp.449-456
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    • 2007
  • Purpose : Antibody persistence after primary series of Haemophilus influenzae type b (Hib) vaccine and responses to a boosters are little known in Korean children. We performed this study to evaluate the antibody titer in relation with a booster immunization of Hib vaccine in Korean children. Methods : One hundred forty-four children aged 12-23 months old were enrolled in three university hospitals. The immunogenicity of a boosters with Hib vaccine was assessed in children previously primed with Hib vaccine. Antibody persistence was also assessed in children who had received 3 doses of Hib vaccine without a booster. Anti-polyribosylribitol phosphate (PRP) IgG antibody levels and bactericidal titers were determined by enzyme immunoassay and bactericidal assay at the Center for Vaccine Evaluation and Study, Medical Research Institute, Ewha Womans University. Results : Prior to a booster in the second year of life, geometric mean antibody concentrations were $2.39{\mu}g/mL$ and the percent of subjects who had a anti-PRP antibody level ${\geq}1{\mu}g/mL$ was 68.6%. After boosting, antibody concentration was $19.09{\mu}g/mL$ and the percent of subjects who had a anti-PRP antibody level ${\geq}1{\mu}g/mL$ was 96.5%, which reflects previous immune priming. In subjects who had finished primary immunization only, the bactericidal titer was 3,946 and in subjects who had a booster, it was 11,205. Anti-PRP antibody level was correlated with serum bactericidal titer. Conclusion : Many children aged 12-23 month old still had protective antibodies after recommended primary immunization only. A booster dose seemed to induce good anamnestic antibody responses in Korean children.

Biological Study on the Increment of Survival Rate during Early Life Cycle in th Rockfish, Sebastes schlegeli (Telostei: Scorpaenidae) - I. Effects of Ammonia on Survival and Growth of the Larvae and Juveniles Stage (조피볼락, Sebastes schlegeli의 초기생활사 동안 생존율 향상을 위한 생물학적 연구 - I. 자어의 생존과 성장에 미치는 암모니아의 영향)

  • Chin, Pyung;Shin, Yun-Kyung;Kim, Hak-Gyoon;Lee, Jeong-Sick;Kim, Hyung-Soo
    • Korean Journal of Ichthyology
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    • v.10 no.1
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    • pp.98-105
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    • 1998
  • The effect of ammonia on survival and growth of the larval rockfish, Sebastes schlegeli was examined by a static renewal bioassay method. The tolerance of larvae to ammonia toxicity was more sensitive at the early larvae, but increased with the development of larvae. In 14 day-old-larvae after parturition, the mortality with treatment of each concentration of ammonia was 5% at control group and 0.0112 $NH_3$mg/l, whereas it was increased up to 27.5% at exposure group of 0.1230 $NH_3$mg/l with higher concentration. Regression equation between ammonium concentration(X) and mortality(Y) was followed; Y=0.516+3.482 X($r^2=0.4737$, P<0.01). The NOEC(no-observable-effect concentration) and LOEC (lowest-observable-effect concentration) to mortality compared to control group were 0.100 $NH_3mg/l$ and 0.1230 $NH_3$mg/l, respectively and chronic value(ChV) which is the geometric mean of the NOEC and LOEC was 0.1110 $NH_3$mg/l. Body length after 7-days exposure in control group, 0.0112 $NH_3$mg/l and 0.1230 $NH_3$mg/l were 7.8325mm, 7.700mm and 7.05mm, respectively. The NOEC, LOEC and chronic value(ChV) were 0.0335 $NH_3$mg/l, 0.0558 $NH_3$mg/l and 0.0432 $NH_3$mg/l, respectively.

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Antibody Responses in Hematopoietic Cell Transplantation Recipients after Vaccination Against Haemophilus Influenzae Type b and Streptococcus pneumoniae (소아 조혈모세포 이식 환자에서 b형 헤모필루스 인플루엔자와 폐렴구균 백신 접종 후 항체 반응에 관한 연구)

  • Kim, Yae-Jean;Hwang, Ji-Young;Choi, Soo-Han;Kong, Eunhye;Kim, Yanghyun;Park, Ki-Sup;Yoo, Keon-Hee;Sung, Ki-Woong;Koo, Hong Hoe;Kim, Kyung-Hyo
    • Pediatric Infection and Vaccine
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    • v.21 no.2
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    • pp.81-95
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    • 2014
  • Purpose: Hematopoietic cell transplantation (HCT) recipients are vulnerable to invasive infection by Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (Sp). This study was performed to evaluate immune responses after Hib and Sp vaccination in Korean pediatric HCT recipients. Methods: Patients were prospectively enrolled at Samsung Medical Center during 2009-2011. ELISA tests to detect anti-PRP IgG antibody and antibodies to Sp serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F were performed at the Center for Vaccine Evaluation and Study, Ewha Medical Research Institute. Results: Ten patients (two allogeneic, eight autologous recipients) with median age 5.4 years (range 2.7-12.2 years) were enrolled. Before Hib vaccination, 60% of patients' anti-PRP IgG titers were below $0.15{\mu}g/mL$. After vaccination, 100% of patients' anti-PRP IgG titers increased above $0.15{\mu}g/mL$ (cut-off value for detection) and $1.0{\mu}g/mL$ (cut-off value for seroprotection). For pneumococcus, in 2-5 year-old patients, pre-vaccination geometric mean concentrations (GMCs) of IgG for six serotypes (4, 6B, 9V, 14, 18C, and 23F) were below $0.35{\mu}g/mL$ and at 5 months post-vaccination GMCs of IgG for all seven serotypes increased to above $0.35{\mu}g/mL$. In patients older than 5 years, pre-vaccination GMCs of IgG for four serotypes (4, 9V, 14, and 23F) were below $0.35{\mu}g/mL$ and at 3 months post-vaccination GMCs of IgG for all seven serotypes increased to above $0.35{\mu}g/mL$. Conclusion: Most HCT recipients had low or no protective antibodies to Hib and Sp before vaccination, but showed good immune responses to protective levels after vaccination.

DEVELOPMENT OF SAFETY-BASED LEVEL-OF-SERVICE CRITERIA FOR ISOLATED SIGNALIZED INTERSECTIONS (독립신호 교차로에서의 교통안전을 위한 서비스수준 결정방법의 개발)

  • Dr. Tae-Jun Ha
    • Proceedings of the KOR-KST Conference
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    • 1995.02a
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    • pp.3-32
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    • 1995
  • The Highway Capacity Manual specifies procedures for evaluating intersection performance in terms of delay per vehicle. What is lacking in the current methodology is a comparable quantitative procedure for ass~ssing the safety-based level of service provided to motorists. The objective of the research described herein was to develop a computational procedure for evaluating the safety-based level of service of signalized intersections based on the relative hazard of alternative intersection designs and signal timing plans. Conflict opportunity models were developed for those crossing, diverging, and stopping maneuvers which are associated with left-turn and rear-end accidents. Safety¬based level-of-service criteria were then developed based on the distribution of conflict opportunities computed from the developed models. A case study evaluation of the level of service analysis methodology revealed that the developed safety-based criteria were not as sensitive to changes in prevailing traffic, roadway, and signal timing conditions as the traditional delay-based measure. However, the methodology did permit a quantitative assessment of the trade-off between delay reduction and safety improvement. The Highway Capacity Manual (HCM) specifies procedures for evaluating intersection performance in terms of a wide variety of prevailing conditions such as traffic composition, intersection geometry, traffic volumes, and signal timing (1). At the present time, however, performance is only measured in terms of delay per vehicle. This is a parameter which is widely accepted as a meaningful and useful indicator of the efficiency with which an intersection is serving traffic needs. What is lacking in the current methodology is a comparable quantitative procedure for assessing the safety-based level of service provided to motorists. For example, it is well¬known that the change from permissive to protected left-turn phasing can reduce left-turn accident frequency. However, the HCM only permits a quantitative assessment of the impact of this alternative phasing arrangement on vehicle delay. It is left to the engineer or planner to subjectively judge the level of safety benefits, and to evaluate the trade-off between the efficiency and safety consequences of the alternative phasing plans. Numerous examples of other geometric design and signal timing improvements could also be given. At present, the principal methods available to the practitioner for evaluating the relative safety at signalized intersections are: a) the application of engineering judgement, b) accident analyses, and c) traffic conflicts analysis. Reliance on engineering judgement has obvious limitations, especially when placed in the context of the elaborate HCM procedures for calculating delay. Accident analyses generally require some type of before-after comparison, either for the case study intersection or for a large set of similar intersections. In e.ither situation, there are problems associated with compensating for regression-to-the-mean phenomena (2), as well as obtaining an adequate sample size. Research has also pointed to potential bias caused by the way in which exposure to accidents is measured (3, 4). Because of the problems associated with traditional accident analyses, some have promoted the use of tqe traffic conflicts technique (5). However, this procedure also has shortcomings in that it.requires extensive field data collection and trained observers to identify the different types of conflicts occurring in the field. The objective of the research described herein was to develop a computational procedure for evaluating the safety-based level of service of signalized intersections that would be compatible and consistent with that presently found in the HCM for evaluating efficiency-based level of service as measured by delay per vehicle (6). The intent was not to develop a new set of accident prediction models, but to design a methodology to quantitatively predict the relative hazard of alternative intersection designs and signal timing plans.

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A Study on the Concentration of Nanoparticles and Heavy Metals in Indoor/Outdoor Air in a University Administrative Public Office (대학교 행정실 실내 외 공기 중 나노입자와 중금속 농도에 관한 연구)

  • Choi, Su-Hyeon;Im, Ji-Young;Park, Hee-Jin;Chung, Eun-Kyung;Kim, Jong-Oh;Son, Bu-Soon
    • Journal of Environmental Health Sciences
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    • v.38 no.6
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    • pp.493-502
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    • 2012
  • Objectives: The purpose of this study is to investigate the mass concentration of nanoparticles and understand the characteristics of elements of heavy metal concentrations within nanoparticles in the air using Micro-Orifice Uniform Deposit Impactor Model-110 (MOUDI-110), based on indoor and outdoor air. Methods: This Study sampled nanoparticles using MOUDI-110 indoors (office) and outdoors at S University in Asan, Korea in order to reveal the concentration of nanoparticles in the air. Sampling continued for nine months (10 times indoors and 14 times outdoors) from March to November 2010. Mass concentrations of nanoparticle and concentrations of heavy metals (Al, Mn, Zn, Ni, Cu, Cr, Pb) were analyzed. Results: Indoors, geometric mean concentration of nanoparticles ranged in size from 0.056 ${\mu}m$ to 0.10 ${\mu}m$ and those of 0.056 ${\mu}m$ or less recorded 0.929 ${\mu}g/m^3$ and 1.002 ${\mu}g/m^3$, respectively. On the other hand, the levels were lower outdoors with 0.819 ${\mu}g/m^3$ and 0.597 ${\mu}g/m^3$. Mann-Whitney U tests showed that the difference between the indoors and the outdoors was statistically meaningful in terms of particles of 0.056 ${\mu}m$ or less (p<0.05) in size. These results are possibly influenced by the use of printers and duplicators as the factor that increased the concentration of nanoparticles. In seasonal concentration distribution, the level was higher during the summer compared to in the autumn. Those of 0.056 ${\mu}m$ or less in size presented a statistically meaningful difference during the summer (p<0.05). These results may be influenced by photochemical event as the factor that makes the levels high. Regarding zinc, among the other heavy metals, the fine particles ranged in size from 0.056 ${\mu}m$ to 0.10 ${\mu}m$ and those of 0.056 ${\mu}m$ or less recorded 1.699 $ng/m^3$ and 1.189 $ng/m^3$ in the outdoors. In the indoors, the levels were lower, with 0.745 $ng/m^3$ and 0.617 $ng/m^3$. Cr and Ni at the size of 0.056 ${\mu}m$ or less, both of which have been known to pose severe health effects, recorded higher concentrations indoors with 0.736 $ng/m^3$ and 0.177 $ng/m^3$, compared to 0.444 $ng/m^3$ and 0.091 $ng/m^3$ outdoors. By season, Zn, Ni, Cu and Pb posted a high level of indoor concentration during the fall. As for Cr, the level of concentration indoors was higher than outdoors both during the summer and the autumn. Conclusion: This study indicates the result of an examination of nano-sized particles and heavy metal concentrations. It will provide useful data for the determination of basic nanoparticle standards in the future.

The immunogenicity and safety of three-component DTaP vaccine in Korean infants (우리나라 영아에서 3가 정제 백일해 항원 DTaP 백신의 면역원성 및 안전성)

  • Kang, Jin Han;Kim, Jong Hyun;Lee, Jung Hyun;Lee, Soo Young;Hong, Young Jin;Kim, Chang Hwi
    • Clinical and Experimental Pediatrics
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    • v.50 no.4
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    • pp.355-362
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    • 2007
  • Purpose : We conducted the study to evaluate the immunogenicity and safety of three component DTaP vaccine ($Infanrix^{(R)}$) in a group of Korean healthy infants on a three-dose primary vaccination. And we compared the immunogenicity of this DTaP vaccine with two component DTaP vaccine which has been widely used in Korea. Methods : We enrolled one hundred fifty one healthy infants aged 8-9 weeks. These infants were vaccinated at age 2, 4 and 6 months of age with three component DTaP vaccine. Solicited adverse events were actively monitored for 72 hours following each vaccination, and all adverse events after each vaccination were observed for three weeks. Anti-diphtheria toxoid Ab., anti-tetanus toxoid Ab., anti-pertussis toxin Ab., anti-filamentous hemagglutinin Ab., and anti-pertactin Ab. were measured using ELISA for assessing immunogenicity of study vaccine in 60 infants. Immunogenicity analysis of two component DTaP vaccine was performed with same methods in 14 infants as control. Results : The seroconversion rates of anti-diphtheria toxoid Ab, anti-tetanus toxoid Ab. anti-filamentous hemagglutinin Ab. were 100% in both group. Seroconversion rate of anti-pertactin Ab in study group was 100%, but the rate in control group was 50%. However, geometric mean concentration of anti-pertussis toxin Ab. was higher in control group. Mild local and systemic reactions were observed within three days after vaccination, and no serious adverse events related study vaccine were happened during study period. Conclusion : Our study results suggest that three component DTaP vaccine ($Infanrix^{(R)}$) is a well-tolerable and high immunogenic vaccine, especially anti-Pertactin Ab. of the study vaccine is very immunogenic. It can be available as routine DTaP vaccination in our infants.

Airborne Concentrations of Welding Fume and Metals of Workers Exposed to Welding Fume (용접사업장 근로자의 흄 및 금속 노출농도에 대한 평가와 혈중 금속 농도)

  • Choi, Ho-Chun;Kim, Kangyoon;An, Sun-Hee;Park, Wha-Me;Kim, So-Jin;Lee, Young-Ja;Chang, Kyou-Chull
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.9 no.1
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    • pp.56-72
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    • 1999
  • Airborne concentrations of welding fumes in which 13 different metals such as Al, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Si, Sn, Ti, and Zn were analyzed were measured at 18 factories including automobile assembly and manufactures, steel heavy industries and shipyards. Air samples were collected by personal sampler at each worker's worksite(n=339). Blood levels of Cd, Cu, Fe, Mn, Pb and Zn were also measured from samples taken from 447 welders by atomic absorption spectrometry and compared with control values obtained from 127 non-exposed workers. The results were as follows ; 1. Among various welding types, $CO_2$ welding 70.2 % were widely used, shielded metal arc welding(SMAW) 22.1 % came next, and rest of them were metal inert gas(MIG) welding, submerged arc welding(SAW), spot welding(SPOT) and tungsten inert gas(TIG) welding. 2. Welding fume concentration was $0.92mg/m^3$($0.02{\sim}15.33mg/m^3$) at automobile assembly and manufactures, $4.10mg/m^3$($0.02{\sim}70.75mg/m^3$) at steel heavy industries and $5.59mg/m^3$($0.30{\sim}91.16mg/m^3$) at shipyards, respectively, showing significant difference among industry types. Workers exposed to high concentration of welding fumes above Korean Permissible Exposure Limit(KPEL) amounted to 7.9 % and 12.5 %, in $CO_2$ welding and in SMAW at automobile assembly and manufactures and 62.7 % in $CO_2$ welding, and 12.5 % in SMAW at shipyards, and 66.2 % in $CO_2$ welding and 70.6 % in SMAW at steel heavy industries. 3. Geometric mean of airborne concentration of each metal released from welding fumes was below one 10th of KPEL in all welding types. Percentage of workers, however, exposed to airborne concentration of metals above KPEL amounted to 16.8 % in Mn and 7.6 % in Fe in $CO_2$ welding; 37.5 % in Cu in SAW, 30 % in Cu in TIG; and 25 % in Pb in SPOT welding. As a whole, 76 Workers(22.4%) were exposed to high concentration of any of the metals above KPEL. 4. There were differences in airborne concentration of metals such as Al, Cd, Cr, Cu. Fe. Mn, Mo, Ni, Pb, Si, Sn, Ti and Zn by industry types. These concentrations were higher in shipyards and steel heavy industries than in automobile assembly and manufactures. Workers exposed to higher concentration of Pb above KPEI amounted to 7.4 % of workers(7/94) in automobile assembly and manufactures. In shipyards, 19.2 % of workers(19/99) were over-exposed to Mn and 7.1 % (7/99) to Fe above KPEL. In steel heavy industries, 14.4 %(21/146), 7.5 %(11/146) and 13 %(19/146) were over-exposed to Mn, Fe and Cu, respectively. As a whole, 76 out of 339 workers(22.4%) were exposed to any of the metals above KPEL. 5. Blood levels of Cd, Cu, Fe, Mn, Pb, and Zn in welders were $0.11{\mu}g/100m{\ell}$, $0.84{\mu}g/m{\ell}$, $424.4{\mu}g/m{\ell}$, $1.26{\mu}g/100m{\ell}$, $5.01{\mu}g/100m{\ell}$ and $5.68{\mu}g/m{\ell}$, respectively, in contrast to $0.09{\mu}g/100m{\ell}$, $0.70{\mu}g/m{\ell}$, $477.2{\mu}g/m{\ell}$, $0.73{\mu}g/100m{\ell}$, $3.14{\mu}g/100m{\ell}$ and $6.15{\mu}g/m{\ell}$ in non-exposed control groups, showing significantly higher values in welders but Fe and Zn.

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