Background: In Korea, a healthy 36-year-old man developed acute interstitial pneumonitis soon after inhaling a waterproofing spray which he had applied at home to his outdoor jacket. Objectives: The objectives of this study were to review cases of varying degrees of respiratory toxicity and poisoning in connection with the use of waterproofing spray and summarize major reasons for cases of poisoning. Methods: We searched articles reporting on a combination of a waterproofing agent and/or respiratory symptoms, including acute respiratory syndrome, lung injury, pneumonia, pulmonary toxicity, and respiratory disease. Results: We reviewed a number of cases of varying degrees of respiratory toxicity and poisoning resulting from inhalation of waterproofing spray containing fluorocarbon co-polymer, solvents and propellants reported in a variety of countries. The literature searches concluded that among the ingredients of waterproofing agents, fluorinated polymer may cause acute respiratory health effects. Conclusion: Environmental policy should be implemented in order to prevent consumers from using household and industrial products including waterproofing agents. In addition, a national surveillance system should be created to collect cases of poisoning caused by the use of consumer products.

Objectives: Due to global warming resulting from climate change, there has been increasing interest in the relationship between temperature and mortality. These temperature-related deaths depend on diverse conditions related to a given place and person, as well as on time. This study examined changes in the impact of high temperatures on death in summer, using the effect and burden of elevated temperatures on deaths in Seoul and Daegu. Methods: A Poisson regression model was used to estimate short-term temperature effects on mortality. Temperature-related risks were divided into three time periods of equal length (1996-2000, 2001-2005, and 2006-2010). In addition, in order to compare the impact of high temperatures on deaths, this study calculated the proportion of attributable deaths to population, which simultaneously considers the threshold and the slope above the threshold. Results: The effect and burden of high temperatures on deaths is high in Daegu. However, the impact (i.e. the effect and burden) of elevated summer temperatures on deaths has declined over the past 15 years. Sensitivity analyses using alternative thresholds show the robustness of these findings. Conclusion: This study suggests that the attributable burden of high temperatures on deaths to be more plausible than relative risk or threshold for comparing the health impact of high temperatures across populations. Moreover, these results contain important implications for the development or the adjustment of present and future strategies and policies for controlling the temperature-related health burden on populations.

Objectives: This study aims to investigate the AD (allergic diseases: asthma, allergic rhinitis and atopic dermatitis) prevalence among elementary schoolchildren in an industrial city, Ulsan, and identify major environmental risk factors associated with AD prevalence. Methods: Data on the physician-diagnosed prevalence over the past 12 months and potential risk factors of AD were collected through a questionnaire from a 2009-2010 survey of 4,067 schoolchildren living in different urban environments. The logistic regression analysis was performed to assess differences in AD prevalence among the areas and to determine which environmental factors impacted AD. Results: Our survey results showed that the AD prevalence rate ranged between 26.2% and 35.9%. Children living in polluted areas (near industrial and central urban areas) had about a 10% higher prevalence of AD than did those living in coastal or suburban residences. The Chi-Square test demonstrated that this local difference was statistically significant before and after adjustment of major confounders such as parental AD history and parental education. The results of the logistic regression analysis showed a statistically significant association between several environmental factors (ventilation in winter, odor conditions and exposure to traffic smoke, and outdoor $PM_{10}/O_3$ pollution) and the prevalence of AD found by multivariate model after adjusting confounders. Conclusion: These results suggest that local differences in AD prevalence are significantly associated with outdoor environmental factors. Although there are likely to be other risk factors for AD, living in a polluted area and exposure to high levels of air pollutants can contribute to an increased risk of childhood AD.

Objectives: The main purpose of this study is to produce background data which can be compared with data on vulnerable areas such as industrial complexes in Ulsan, SihwaBanwol, Gwangyang, Yeosu, Pohang, Cheongju and Daesan in Korea. Methods: This study was performed on 1,007 local residents in Gangneung using personal questionnaires and medical check-up. Environmental pollutants including heavy metals in blood and urine were analyzed and the results are as follows. Results: According to the results of medical check-up, 705 subjects were "Normal (A and B)", 232 subjects were "Disease doubtful (R1)" and 70 subjects were "High blood pressure or Diabetes doubtful (R2)". Regarding geometric mean concentration, blood lead was 1.57 ${\mu}g/dL$, urine cadmium was 0.82 ${\mu}g/g-cr$, urine mercury was 0.98 ${\mu}g/g-cr$ and urine arsenic was 15.78 ${\mu}g/g-cr$. In the analysis of 11 kinds of VOCs in blood, vinyl chloride, 1,3-butadiene and dichloroethylene were not detected, while the detection rate of other chemicals was above 70% except chloroform(49.7%) and trichloroethylene(19.0%). In analysis of 16 kinds of PAHs in blood, 10 kinds showed more than 80% in detection rate. Also, detection rate of 4 kinds of PCBs in blood ranged 52 to 78%. Conclusions: Compared with industrial compelxes, the concentration of blood lead was lower, while urine cadmium and mercury levels were similar. Also, urine arsenic ranged at a significant level. Further study is required to find the cause of regional differences in concentrations of environmental pollutants.

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.

Objectives: This study was performed in order to evaluate the generation characteristics of airborne bacteria and fungi while operating a household humidifier, in consideration of user habits. Methods: Microbial samples were collected in a closed chamber with a total volume of 2.76 $m^3$, in which a humidifier was operated according to experimental strategies. A cultivation method based on the viable counts of mesophilic heterotrophic bacteria and fungi was performed. Experimental strategies were divided into three classes: the type of water in the water reservoir (tap water, cooled boiled water); the frequency of filling the reservoir (refill every day, no refill); and the sterilization method (sterilization function mode, humidifier disinfectants). Results: Significant increases in the concentration of airborne bacteria were observed while the humidifier was in operation. The concentration had increased to 2,407 $CFU/m^3$ by 120 hours when tap water filled the reservoir without any application of sterilization, while for cooled boiled water, it was merely 393 $CFU/m^3$ at a similar time point. Usages of disinfectant in the water tank were more effective in decreasing bioaerosol generation compared to sterilization function mode operation. Generation characteristics of airborne fungi were similar to those of bacteria, but the levels were not significant in all experiments. Calculated exposure factor can be used as an indicator to compare biorisk exposure. Conclusion: This study identified the potential for bioaerosol generation in indoor environments while operating a household humidifier. User practices were critical in the generation of bioaerosol, or more specifically, airborne bacteria. Proper usage of a humidifier ensures that any biorisks resulting from generated bioaerosol can be prevented.

Objectives: This study was conducted in order to evaluate the microbiological contamination of the indoor air of the lunchrooms at child care centers and investigate the toxin genes and toxin production ability of food-borne pathogens. Methods: A total of 64 child care centers were sampled to test total aerobic bacteria, coliform bacteria, fungi, Staphylococcus aureus, Bacillus cereus and Salmonella spp. according to the Korea Food Code. All toxin genes of pathogens were detected using the Polymerase Chain Reaction method. The Sthaph. aureus enterotoxin was detected by a Staphylococcus aureus enterotoxin-reversed passive latex agglutination kit. The heamolysin BL (HBL) and non-heamolytic enterotoxin (NHE) produced by B. cereus were detected using a B. cereus enterotoxin-reversed passive latex agglutination kit and Bacillus diarrheal enterotoxin visual immunoassay kit, respectively. Results: The means of total aerobic bacteria and coliform bacteria were $1.91{\pm}1.84$ log CFU/plate and $0.47{\pm}0.62$ log CFU/plate, respectively. The mean of fungi also showed $0.59{\pm}0.71$ log CFU/plate. Among the pathogenic bacteria tested in this study, Staphy. aureus and B. cereus were detected in four (6.3%) and 21 (32.8%) out of 64 indoor air samples from lunchrooms in child care centers, respectively. All Staphy. aureus tested in this study possessed no toxin genes and did not produce enterotoxin. The detection rate of nheABC, hblCDA, entFM and ces toxin gene in B. cereus was 100, 57.1, 76.2 and 0%, respectively. B. cereus isolates were classified into four groups according to the presence or absence of toxin genes. The nheABC gene was the major toxin gene among B. cereus tested in this study. The HBL was detected in 11 out of 21 B. cereus isolates (52.4%) and three B. cereus isolates produced NHE (14.3%). Conclusion: The results indicated that the contamination by microorganisms in the indoor air of lunchrooms was unqualified to supply safe catering in child care centers. The ongoing control of indoor air quality is required.

Objective: This study was performed to assess bacterial distribution concerned in sanitation management of public lavatory in Seoul. Methods: In this research, bacteriological investigation on public lavatory was accomplished for bidet water, bidet nozzle, washbowl and lavatory stool in the 50 public facilities such as public institutions, subway stations, cinema, department stores, large-scale buildings and hospitals amount to 374 specimens. Results: The geometric mean of colony forming unit(CFU) in total aerobic colony count were analyzed as follows; $5.2{\times}10^2/100cm^2$ on lavatory stool, $7.2{\times}10^3/ea$ on bidet nozzle, $7.8{\times}10^3/ea$ on center ring of washbowl, $1.4{\times}10/mL$ in bidet water (ml) and 7.0/ea on doorknob. Opportunistically pathogenic germs such as Staphylococcus aureus, Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa were isolated in 3.7%, 5.9%, 3.2% and 1.9% of total specimens, respectively. Conclusion: The result of this study shows that there were some facilities where the pathogenic germs were detected to may cause urological infection. And the CFU of general bacteria as the representative indicator of disinfection and lavatory cleaning were high enough to imply the improvement of sanitation management of public lavatories should be contrived.

Objective: This research was performed to evaluate the state of oil pollution in an area surrounding a railway station that has over 100 years of business history as a railway station in S City, Korea. The amount of polluted soil was estimated, and the target area for remediation was assessed in this study to restore the oil-polluted area. Methods: To accomplish this aim, five observation wells were installed for the sampling of groundwater, and soil was sampled at 33 points. Electric resistance studies and a trench investigation were undertaken to understand the geological conditions of the site, and the groundwater movement in this area was simulated by MODFLOW. Physiochemical analyses were conducted to determine the quality of the groundwater and the current state of oil pollution influenced by that of the soil. Results: The mean level of total petroleum hydrocarbons (TPHs) in this area was 1,059 mg/kg, and the area for remediation was determined to be 7,610 mg/kg. Levels of benzene, toluene, ethylbenzene, and xylene (BTEX) were determined to be under the legal standard. Conclusion: In terms of depth, the biggest area polluted by TPH found was between 0 and 1 m from ground level, and the affected area was 5,900 $m^3$. TPHs were not detected in groundwater. Diesel and lubricating oil were the main causes of TPH pollution at this railway station.

Objectives: This study was undertaken in order to evaluate a potential mechanism involved in gastro-intestinal problems observed in autistic subjects and uses an animal model of autism investigation. Methods: BTBR T+tf/J, a mouse strain with typical socio-behavioral characteristics of autistic subjects and FVB mice with highly social behaviors as the control strain were used. Both genders of mice aged three weeks and six months were used from four separate litters for each strain. Serum was prepared following cardiac puncture, and mesenteric lymph nodes were collected for in vitro stimulation and enumeration of major immune cell proportion. Results: The level of serum IgA was significantly enhanced in six-month-old BTBR mice compared with three-week-old BTBR, which was not observed with the FVB control mice. The serum IgE level was also higher among BTBR mice than among age-sex matched FVB mice, respectively. Considering the ratio of interleukin-4 vs interferon-gamma production from mesenteric lymph node T cells, skewedness toward type-2 reactivities was observed. In addition, the proportion of B cells in mesenteric lymph nodes was significantly higher in BTBR mice than in FVB mice. Conclusion: Upregulation of mucosal immunity related with enhanced type-2 immune reactivity observed in BTBR mice could be involved with the etiology of gastro-intestinal abnormalities in autism.

Objectives: QSAR methodology was applied to explain two different sets of acceptable daily intake (ADI) data of 74 pesticides proposed by both the USEPA and WHO in terms of setting guidelines for food and drinking water. Methods: A subset of calculated descriptors was selected from Dragon$^{(R)}$ software. QSARs were then developed utilizing a statistical technique, genetic algorithm-multiple linear regression (GA-MLR). The differences in each specific model in the prediction of the ADI of the pesticides were discussed. Results: The stepwise multiple linear regression analysis resulted in a statistically significant QSAR model with five descriptors. Resultant QSAR models were robust, showing good utility across multiple classes of pesticide compounds. The applicability domain was also defined. The proposed models were robust and satisfactory. Conclusions: The QSAR model could be a feasible and effective tool for predicting ADI and for the comparison of logADIEPA to logADIWHO. The statistical results agree with the fact that USEPA focuses on more subtle endpoints than does WHO.

Objectives: Parabens are widely used as antimicrobial agents in pharmaceuticals and cosmetics as well as by the food industry. Parabens have been reported to show weak estrogenic activity and be related to health effects such as allergic reactions and skin and breast cancer. We evaluated an online solid phase extraction (SPE) method coupled with LC-MS/MS technique using free and conjugated parent parabens in human urine for assessing human exposure to parabens. Methods: We employed LC/MS/MS through online solid phase extraction and column-switching techniques and analyzed free and conjugated parabens as biomarkers of human exposure. Four major parabens, methyl-paraben (MP), ethyl-paraben (EP), propyl-paraben (PP) and butyl-paraben (BP), were analyzed. Method validation was performed by sensitivity, accuracy, precision and comparison of the results of online SPE with offline SPE. Results: The limits of detection (LOD) were in the range of 0.2-2 ng/mL, and actual limits of quantification (LOQ) were in the range of 0.7-6 ng/mL urine, depending upon the compound. Accuracy was in the range of 98.3-106.4%, and precision was in the range of 1.3-8.7% (CV) depending upon the compound. We found a good correlation between the results of analysis by online SPE method and that by off-line SPE method. Conclusions: The online SPE method showed proper LOD and validated accuracy, precision and good correlation with the offline method for analyzing parabens in urine.

Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.