Objectives : The purposes of this study were to evaluate exhaust ventilation systems(EVSs) and to suggest problems and improvements. Methods : For 50 small and medium-sized enterprises, we carried out evaluation of EVSs. We evaluated hoods with smoke tester and measurement of capture velocity. In addition, we used several indicators for performance evaluation designed in this study. Results : 1. Based on the smoke flow pattern and the criteria of occupational health and safety act, 67.8% of hoods were rated 'good' level at smoke test whereas 26.3% were rated 'good' level at measurement of capture velocity. 2. 29.3% of hoods, of which ratio of measured actual air flow at hood(Qah) to required ideal exhaust air flow at hood(Qih) was 1 or more, were rated 'good' level. 3. The % of EVS, of which ratio of measured actual air flow at stack(Qast) to total required ideal exhaust air flow at hood(Qith) was 1 or more, was 29.0%. 4. For the ratio of measured Qast to existing air flow at fan(Qfan), only 5% of EVSs were 1 or more and 26.0% were 0.8 or more but less than 1.0. 5. For the ratio of measured Qast to total measured actual exhaust air flow at hood(Qath), 74.0% were 0.8 or more but less than 1.0. 6. The percentage of EVS, of which ratio of total measured Qath to existing Qfan was 0.8 or more, was 19.0%. 7. The percentage of EVS, of which ratio of total measured Qath to total required ideal exhaust Qith was 1 or more, was 26.0%. 8. For the comprehensive evaluation indicators designed in this study, 29.0% were 0.8 or more. Conclusions : We found that few exhaust local ventilations at small and medium-sized enterprises were rated 'good' level and that most exhaust local ventilations had 'poor' design and installation. Therefore, relevant professional manpower and enterprises have to construct exhaust local ventilation where it is needed, and technical guidance and economic support are needed to improve 'poor' exhaust local ventilation after self-evaluation.

To provide necessary information for future environmental monitoring of smelting and litharge making industries in Korea, environmental monitoring dataset of air lead concentration of 4 lead industries(1 primary smelting, 2 secondary smelting and 1 litharge making industry) were analyzed from 1994 to 2007. Data were compared using geometric mean and standard deviation with minimum and maximum values according to year of measurement, type of lead industries and type of operation of lead industries. The geometric mean and standard deviation of air concentration for a total of 1140 samples in all lead industries for overall 14 years were 70.7${\mu}g/m^3$ and 5.51 with minimum of 1${\mu}g/m^3$ and maximum of 9,185 ${\mu}g/m^3$. The overall geometric means of air concentration were above the permissible exposure levels(PEL) until year of 2001 and thereafter they were remained at the level of half of PEL. The geometric means of primary smelting, secondary smelting and litharge making industry for overall 14 years were 21.7${\mu}g/m^3$(number of samples: 353), 82.5${\mu}g/m^3$(number of samples: 357) and 164.2 ${\mu}g/m^3$(number of samples: 430) respectively. In primary smelting industry, the highest geometric mean air concentration was 35.4 ${\mu}g/m^3$ in the secondary smelting operation; followed by casting operation (24.9 ${\mu}g/m^3$) and melting operation (14.9 ${\mu}g/m^3$), respectively. On the other hand, in secondary smelting industries, the highest geometric mean air concentration was 125.4${\mu}g/m^3$ in melting operation; followed by casting operation (90.5${\mu}g/m^3$) and pre-treatment operation (43.4${\mu}g/m^3$), respectively. However, in litharge making industries, there were no significant differences of geometric mean air concentrations between litharge operation and stabilizer operation. The proportion of over PEL (50${\mu}g/m^3$) was highest in litharge industry and followed by secondary smelting industries. However The proportions of over PEL(${\mu}g./m^3.$) were decreased by the years of environmental monitoring. The significant reduction of mean air lead concentration since year of 2000 was observed due to more active environmental engineering control and new introduction of new operation in manufacturing process, but may be also influenced by non-engineering method such as reduction of operation hours or reduction of exposure time during actual environmental measurement by industrial hygienist according to more strict enforcement of occupational and safety law by the government.

This study was designed to investigate the effect of increased blood and tibia lead on the change of bone mineral density in retired male lead workers. One hundred nine retired male lead workers who worked in 4 different lead industries and 51 nonoccupationally lead exposed male subjects were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured by broadband ultrasound attenuation(BUA) at left calcaneous bone area with broadband ultrasound attenuation method of QUS-2(Metra Biosystems Inc, USA). Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.711) and these two variables were negatively correlated with BUA in bivariate analysis. BUA and tibia lead showed significant main effects on the change of blood lead after adjusting covariates. The effect modification by the level of BMD (low: lower than the median of BUA and high: higher than the median of BUA) was observed between the association of tibia lead and blood lead after adjustment of covariates. The subjects who had higher BMD seemed to have lower blood lead by the increase of tibia lead than those of lower BMD. In the multiple regression analysis of blood lead and tibia lead on BUA after adjustment of covariates, only blood lead showed statistically significant effect on BUA. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.

This study was aimed at investigating the gene expression profile in basal ganglia of cadmium exposed rat based on cDNA array analysis. For cDNA array analysis, adult Sprague-Dawley male rats (350 ${\pm}$ 25 g) were intraperitoneally injected with 2.0 mg/kg body weight/day of CdCl2 (0.3 ml) for 5 days. For doserelated gene expression analysis rats were intraperitoneally injected with 0.0, 0.1, 0.3, 1.0 mg/kg body weight/day of CdCl$_2$ for 5 days. Control rats were injected with equal volume of saline. Cadmium concentration of brain was analyzed by atomic absorption spectrophotometer. For cDNA array, RNA samples were extracted from basal ganglia and reverse-transcribed in the presence of [${\alpha}$32P]-dATP. Membrane sets of the Atlas Rat 1.2 array II and Toxicology array 1.2 (Clontech, Palo Alto, CA) were hybridized with cDNA probe sets. RT-PCR was employed to validate the relative gene expression patterns obtained from the cDNA array. Northern blot hybridization methods were employed to assess the dose-related gene expression. Among the 2352 cDNAs, 671 genes were detected in both array sets and 63 genes of 38 classes showed significant (more than two fold) changes in expression. Thirty five of these genes were up-regulated and twenty eight were down-regulated in the cadmium exposed group. According to the dose-related gene expression analysis, heat shock 27 kDa protein (HSP27), neurodegeneration-associated protein 1 (Neurodap 1) genes were significantly up-regulated and melatonin receptor 1a (Mel1a), Kinesin family member 3C (KIF3C), novel kinesinrelated protein (KIF1D) genes were significantly downregulated even in the low-dose of cadmium exposed group (0.1 mg/kg body weight/day). Conclusions Sixty three genes detected in this study can give some more useful informations about the cadmium-induced neurotoxicity in the basal ganglia. As well as, HSP27, Neurodap1, Mel1a, KIF3C and KIF1D genes may be useful for the study of the cadmium-induced neurotoxicity because these genes showed dramatic changes of mRNA levels in response to the low dose of cadmium exposure.

The purpose of this study is to assess the level of fungi concentration in the university laboratories in Seoul, Korea, and to investigate factors contributing to these concentrations. The samples were taken from three spots in each laboratory; the top of sink, the center of laboratory, and the front of ventilation system, i.e fume hood at the chemical laboratory and clean bench/biosafety cabinet at the microbial laboratory. Air samples were collected using the single-stage Anderson sampler (Quick Take 30) at a flow rate of 28.3 l/min for 5 min on nutrient media in Petri-dishes located on the impactor. Fifty-two air samples were collected from 19 different laboratories (13 microbiology laboratories, 6 chemistry laboratories) in the university, and concentrations of airborne fungi showed no significant difference (p>0.05) between microbiology and chemistry laboratory, and also no significant difference at three locations (sink, center, front of ventilation system) in microbiology and chemistry laboratories. Average concentrations of fungi in 19 laboratories ranged from 7 to 459 cfu/$m^3$, with an overall Geometric Mean of 52 cfu/$m^3$. Airborne fungi concentrations of 6 samples (12 %) exceeded 150 cfu/$m^3$, the guideline of WHO. The ratios of Indoor/Outdoor for airborne fungi ranged from 0.2 to 4.8 (mean = 1.6). Related factors were measured such as relative humidity, temperature, and laboratory area. Temperature and laboratory area showed no significant relations to concentrations of airborne fungi except for relative humidity in the laboratory Concentrations of fungi were significant different (p<0.01) between rainy or cloudy and sunny. However, there was no significant difference between general ventilation and nongeneral ventilation.

Green tobacco sickness (GTS) is known as an occupational disease among tobacco harvesters, and a form of acute nicotine intoxication by the absorption of nicotine through the skin from the wet green tobacco plant. On the assumption that GTS may occur by inhalation as well as absorption of nicotine, we measured the airborne nicotine concentration in tobacco field and the processing room of tobacco leaves. We measured the airborne nicotine concentrations in the tobacco field and processing room between 13 and 30 July 2008. All sampling and analyses of airborne nicotine were conducted according to the manual of analytic methods of NIOSH 2551, and we sampled 2 times at 11 points in the tobacco field by area sampling. The sampling in the processing room of tobacco leaves was conducted at 3 points, and earlymorning dew was collected from the tobacco by wringing the moisture into specimen bottles. The airborne nicotine concentration [geometric mean (geometric standard deviation)] in the tobacco field in the P.M. was higher [49.2 mg/$m^3$ (1.3)] than the A.M. concentration [43.4 mg/$m^3$ (1.4)]. Similarly, the nicotine concentration in the processing room of tobacco leaves was 224.4 mg/$m^3$ (1.2), and the concentration of nicotine in the dew was 64.7 mg/${\ell}$ (1.7). Based on our results, the airborne nicotine concentration in the tobacco field and the processing room of tobacco leaves were 100 and 400 times higher than the occupational recommended values (TLV-TWA of 0.5 mg/$m^3$), respectively. In the future, it is hoped that epidemiologic studies and environmental measurements will be conducted for GTS which occurs by inhalation of nicotine. If GTS is confirmed to occur by inhalation of nicotine, respiratory and dermal protective equipment must be distributed.

일샵 종사자들의 1) 공기 중 화학물질에 대한 노출정도를 파악하고 2) 공기 중 미량으로 존재하는 아세톤 및 톨루엔과 요 중 아세톤 및 마뇨산과의 연관성을 분석하여 후자들이 아직도 생물학적인 지표로 유용한지를 알아보고자 본 연구를 실시하였다. 경인 지역소재 9개의 네일숍에 근무하는 20명의 종사자들을 노출군으로 선정하였으며 이 작업과 무관한 일반 여성 20명을 대조군 선정하였다. 작업장 공기는 한 네일숍에 3개씩 총 27개의 시료를 가능한 한 작업자의 호흡영역에서 가장 가까운 곳에서 지역시료로 채취하였다. 공기 중 유기증기 13개 물질, 포름알데히드, 요 중 아세톤, 요 중 마뇨산을 가스크로마토그래프, 자외선분광광도계 그리고 GC/MS를 이용하여 분석하였다. 유기증기 13개 물질 중 아세톤과 톨루엔은 모든 네일샵에서 검출되었다. 각 네일샵 공기 중 유기증기의 노출정도를 기하평균(GM)과 복합물질간 상가작용을 이용하여 평가를 하였을 때 노동부 노출기준의 10%, ACGIH의 13% 수준에 불과하여 네일샵 종사자들의 유기증기에 대한 직업적인 노출정도는 매우 낮은 것으로 판단되었다. 요 중 아세톤과 마뇨산은 공기 중 아세톤과 툴루엔과 약한 상관성을 보였다(아세톤의 상관 계수 r=0.49, 톨루엔의 상관계수 r=0.45). 그러나 요 중 아세톤의 농도가 노출군과 대조군 간에 통계적으로 유의하지 않았으며 마뇨산은 대조군에 비해 노출군에서 약간 높은 것으로 나타났다. 따라서 저자들은 공기 중 아세톤과 톨루엔의 농도가 낮은 작업장에서 요 중 아세톤과 마뇨산을 생물학적 지표로 삼는 것은 적절하지 못한 것으로 결론지었다.

This study was conducted to compare the concentration of various air contaminants in nine different laboratories during routine activities. Volatile organic compounds (VOC) were sampled and analyzed using NIOSH Method 1500 and asbestos fibers were sampled and analyzed using NIOSH Method 9002 and 7400. Detectable levels of acetone, toluene and ethanol were found in all the laboratories and xylene and n-hexane were detected in eight of the nine laboratories. All the VOC concentrations were well below the Korean Ministry of Labor's Exposure Limit and American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Values (TLVs). Total VOC concentrations at the university laboratories were significantly higher than those at governmental agency laboratories. Airborne fiber concentrations were below 0.01 fibers/cc, while the concentration of chrysotile was 2% in insulation materials sprayed on the ceiling of one laboratory. While all the governmental agency laboratories (n=4) had fume hoods, two out of the five university laboratories did not have fume hoods. The capture velocity of half of the fume hoods were below the maintenance standard(0.4 m/sec). In conclusion, the study suggests that the current controls in place at both university and government agency laboratories are not sufficient in limiting exposure to harmful chemicals to non-detectable levels, though they appear to be adequate in protecting workers to levels below applicable occupational exposure limits. The study also suggests that researchers working in university laboratories may be exposed to greater levels of contaminant than those working in government agency laboratories.

The purpose of this study is to investigate the appropriate metabolite as biomarker for the biomonitoring of 1,3-butadiene(BD) inhalation exposure. We measured the hemoglobin adducts which were extracted from the blood of the ICR mice inhalation exposure with 100ppm and 500ppm 1,3-butadiene for 2 weeks(5 hr/day ${\times}$ 5 days/week). Hemoglobin adducts were the (N-2-hydroxy-3 -butenyl) valine (HB Val) and (N-2,3,4-trihydroxy-butyl)valine (THB Val). Body weights of the exposure groups were significantly lower from 11 exposure post-day in 100ppm BD inhalation mice and from 7 exposure post-day in 500ppm BD inhalation mice than in control. The levels of HB Val are 0.8~1.7pmol/mg globin for 100ppm BD inhalation exposure, and 2.1~4.4 pmol/mg globin for 500ppm BD inhalation exposure. The levels of THB Val are 15.0~22.0 pmol/mg globin in 100ppm BD inhalation exposure, and 34.8~45.7 pmol/mg globin for 500ppm BD inhalation exposure. So the levels of THB Val and HB Val are proportional relationship with BD exposure level. THB Val is 12.9~18.8 times higher level that HB Val in 100ppm BD exposure group and 10.4~16.6 times higher level than HB Val in 500ppm BD exposure group. We concluded that THB Val is an appropriate metabolite as biomarker for the biomonitoring for BD inhalation exposure.