Amidst the international community"s competition for technological supremacy regarding carbon neutrality and the climate crisis, Korea needs to accumulate technological capabilities and gain a competitive advantage by fostering professionals in the field of climate technology. In particular, Korea urgently needs a mid- to long-term labor force development plan and a labor force demand forecast to support it. Therefore, this study conducted a mid- to long-term labor force demand forecast for each climate technology and industrial sector by linking climate technology industrial statistics and standard industrial classification statistics. Forecast results for the industrial sector indicate high demand for labor force in R&D, electrical and electronics, and chemical industries. Forecast results for the climate technology sector suggest that the labor force demand in energy production and efficiency sectors such as energy demand and storage, renewable energy, and power IT is high. Other results indicate that the growth rate for labor force demand in the climate technology adaptation field is relatively high, and that multi-disciplinary sectors have the highest labor force demand. Therefore, it is imperative to design and implement climate technology labor force development policies for climate technology and related industries with high demand for mid- to long-term labor force, and to increase cooperation among Korean ministries to foster interdisciplinary professionals in climate technology fields.

Interest in smart energy systems as a means to reduce greenhouse gas (GHG) emissions and mitigate climate change has been increasing. In particular, much attention is focused on the building sector, which has the highest potential for GHG reduction. Yet, there have been few studies that have thoroughly and quantitatively analyzed the potential amount of greenhouse gas reduction through introduction of building energy management systems (BEMS). This study focuses on empirical evidence generated by BEMS in Korea and analyzes the benefit to cost ratio of such installations for various types of buildings using individual building-level microdata from large buildings in the 2017 Energy Consumption Survey to quantitatively derive the potential for GHG reduction. According to the main research findings, the BEMS dissemination rate could increase by as much as 21 percent, which induces 3.3 percent of energy saving and 3.4 percent of GHG emission reduction. Among 9 sub-sectors, the telecommunications sub-sector has the largest dissemination rate (87.5 percent), and the department stores sub-sector has the lowest rate (1 percent).

This research studied the effect of factors that are able to form disinfection by-products (DBPs) of chlorination, including natural organic matter (NOM) with sewage, bromide ions, pH and contact time. Trihalomethane (THMs) yield of $0.95{\mu}mol/mg$ was higher than other DBPs yield for the chlorinated humic acid samples. THMs yield of sewage sample was $0.14{\mu}mol/mg$ and haloacetonitriles (HANs) yield in the sewage samples were $0.13{\mu}mol/mg$ but only $0.02{\mu}mol/mg$ for the humic acid samples. As the concentration of bromide ions increased, brominated DBPs increased while chlorinated DBPs decreased, because bromide ions produce brominated DBPs. THMs were highest $(55.55{\mu}g/L)$ at a pH of 7.9 and haloacetic acids (HAAs) were highest $(34.98{\mu}g/L)$ at a pH of 5. Also THMs increased with increasing pH while HAAs decreased with increasing pH. After chlorination, the rate of THMs and HAA formation are faster at initial contact time and then reaches a nearly constant value after 24 hours. This study considers ways to reduce DBP formation by chlorination.

In Korea, data for multi-route trihalomethane (THM) exposure in households using municipal tap water treated with ozone–chlorine or chlorine are unavailable or very limited. Accordingly, the present study was designed to obtain those data by measurements of the THM concentrations in the tap water and indoor and outdoor air in the two types of households, along with an estimation of THM exposure from water ingestion, showering, and the inhalation of indoor air. Chloroform was the most abundant THM in all three media, yet no bromoform was detected in any sample. Similar to previous findings, the winter chloroform concentration in tap water treated with chlorine (22.1 μg/l, median) was significantly higher than that in the tap water treated with ozone–chlorine (16.8 μg/l, median). However, the summer water chloroform concentrations and summer and winter water concentrations of the other two THMs (bromodichloromethane and dibromochloromethane) exhibited no significant difference between the chlorine and ozone–chlorine-treated water. It was suggested that the effects of the water parameters including biochemical oxygen demand of raw water entering water treatment plants should be considered when evaluating the advantage of ozone–chlorine disinfection for THM formation over chlorine disinfection. The indoor air THM concentration trend was also consistent with the water concentration trend. The indoor to outdoor air concentration ratios were comparable with previous studies. The THM exposure estimates from water ingestion, showering, and the inhalation of apartment indoor air when not in the shower suggested that, for residents living in the surveyed households, their exposure to THMs in the home was mostly associated with their household water uses. The THM exposure estimates from tap water ingestion were similar to those from showering.

The principle and methodology of risk assessment was applied to establish the quality standard of potential impurities of drinking water treatment chemicals. The impurities(arsenic, lead, cadmium, chromium, mercury, etc.) are regulated as the contained quantity of chemicals in Korea while they are regulated as the quality standard with the idea of 10% of the national safety drinking water standard in U.S.A(NSF) and Japan(JWWA). According to risk assessment of the current standard implemented in Korea, the excess cancer risk of arsenic and lead were determined in around 10^(-5) and the hazard quotient(HQ) of cadmium and chromium were below 10^(-2), respectively. And the standard concentration of the impurities are regulated as much as 2%~6% of the national drinking water quality standard. The values are more enforced rather than the standards in U.S.A(NSF) and Japan(JWWA) regulating the concentration of impurities the 10% of the national drinking water quality standard. We conclude that the impurities standard of drinking water treatment chemicals should be reconsidered comprehensively concerning the national safety drinking water quality standard and risk assessment.

Chlorine disinfection is carried out for the purpose of sterilization of microbes existing in drinking water. Chlorination may cause the formation of disinfection by-products (DBPs) by the reaction of free chlorine with humic substance in the water. In particular, the DBPs including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloketones exist in tap water. The US Environmental Protection Agency (US EPA) suggests 80 μg/L THMs and 60 μg/L HAAs as maximum contamination levels for drinking water. This study was performed to detect the level of DBPs in drinking water and to measure disinfection by-product formation potential (DBPFP) of raw water with four different properties. After 24 h of chlorination, the measured level of trihalomethane formation potential (THMFP), haloacetic acid formation potential, and haloacetonitrile formation potential ranged from 55.0 to 102.6 μg/L, from 9.1 to 23.6 μg/L, and from 10.3 to 33.6 μg/L, respectively. DBPFP was the highest at pH 7.0 and increased with the reaction time. Among the DBPFP, THMFP was detected more frequently than the others. In the treated water, DBPs were measured with a mean value of 47.0 μg/L. Chloroform, dichloroacetic acid, trichloroacetic acid, and dichloronitrile all known as hazardous compounds, were measured as major parts of DBPs.

OBJECTIVES:Man-made vitreous fibers (MMVFs) can induce cytotoxicity in a way similar to that of other particles, including silica and asbestos fibers. However, as yet the mechanism of MMVF-induced cytotoxicity is still not clear. This report aims to clarify the mechanism of MMVF-induced cytotoxicity in the alveolar macrophage (AM). In this mechanism, an attempt to prove the involvement of the adenosine triphosphate (ATP) generation system and the polyinosinic acid-inhibitable scavenger receptors was made.METHODS:Several parameters were observed for cytotoxicity, such as cell viability, the release of lactic dehydrogenase (LDH) and ATP levels in rat AM's that were treated with refractory ceramic fibers (RF2) and rock wool (RW1). A specially designed ATP generation system was used to determine the effect of MMVF on ATP generation. A scavenger receptor ligand was applied to evaluate the relationship between scavenger receptors and MMVF-induced ATP depletion.RESULTS:A 3-(4,5-dimethylthiazol)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that both RF2 and RW1 caused a decrease in cell viability and this decrease was concentration-dependent. RF2 and RW1 increased the release of LDH with increasing fiber concentration. From these parameters, RF2 was shown to exhibit greater cytotoxicity than did RW1. Both fibers decreased the intracellular ATP content and this decrease was concentration-dependent. The decrease was more pronounced in RW1 than in RF2 at all fiber concentrations. These fibers suppressed succinate-triggered oxygen consumption. Polyinosinic acid, a ligand of the scavenger receptor, inhibited the MMVF-induced decrease in ATP concentration.CONCLUSION:These results suggest that RF2 and RW1 can induce cytotoxicity and ATP depletion in the AM through the polyinosinic acid-inhibitable scavenger receptor. ATP depletion was the important factor in MMVF cytotoxicity, especially by RW1.

Dissolved air flotation (DAF) is currently being received in much attention as an effective process for solid-liquid separation in water technology. In this study, we scaled-up the DAF plant from a pilot-scale (72 m(3)/day) to a full-scale (6000 m(3)/day) plant and the sand-float type DAF was used. The concept of maintaining equal surface loading rate into scaling-up of DAF was a proper practice and strategy. In order to optimize the DAF plant, it was needed to determine the surface loading rare and air dissolving tube pressure. The optimum conditions of surface loading rate and air dissolving tube pressure were indicated in 7.5 m(3)/m(2) day and 440 kPa from the pilot plant, respectively. The removal efficiency for TOC and UV254 from the full-scale plant was as satisfactory as those from the pilot plant for the same surface loading rates. However, especially in flotation zone, the full-scale plant performed a little bit poorer than the pilot-scale plant in turbidity and chlorophyll-a reduction: because hull-scale plant had long retention time and turbulent mixing condition during backwashing time which might be brought about the breakage of fragile flocs.Performance comparisons between the full-scale DAF plant and the conventional plant located at the city of Nam-Yang Ju in Korea are presented. DAF process showed higher efficiency than the conventional settling system improving the water quality in general, namely, turbidity, TOC, UV254, Fe and Mn. We, therefore, conclude that DAF system should have substantial advantages over the conventional settling process in drinking water treatment. (C) 2000 Elsevier Science Ltd. All rights reserved.

The relationship between air pollution and daily mortality for the period 1991-1995 was examined in two Korean cities, Seoul and Ulsan. The observed concentrations of sulfur dioxide (SO2; mean = 28.7 ppb), ozone (O3; mean = 29.2 ppb), and total suspended particulates (TSP; mean = 82.3 microg/m3) during the study period were at levels below Korea's current ambient air quality standards. Daily death counts were regressed separately in the two cities, using Poisson regression on SO2, O3, and/or TSP controlling for variability in the weather and seasons. When considered singly in Poisson regression models controlling for seasonal variations and weather conditions, the nonaccidental mortality associated with a 50-ppb increment in a 3-day moving average of SO2 concentrations, including the concurrent day and the preceding 2 days, was 1.078 [95% confidence interval (CI), 1.057-1.099] for Seoul and 1.051 (CI, 0.991-1.115) for Ulsan. The rate ratio was 1.051 (CI, 1.031-1.072) in Seoul and 0.999 (CI, 0. 961-1.039) in Ulsan per 100 microg/m3 for TSP, and 1.015 (CI, 1. 005-1.025) in Seoul and 1.020 (0.889-1.170) in Ulsan per 50 ppb for 1-hr maximum O3. When TSP was considered simultaneously with other pollutants, the TSP association was no longer significant. We observed independent pollution effects on daily mortality even after using various approaches to control for either weather or seasonal variables in the regression model. This study demonstrated increased mortality associated with air pollution at both SO2 and O3 levels below the current World Health Organization recommendations.

Objectio ostinato the carcinogenic risks from the ingestion of some carcinogenic pesticides (CPs) in vegetables sampled at a local agricultural product market in Seoul. Methods: After applying a hazard identification step, we selected four pesticides, such as DDT, dieldrin, folpet, and heptachlor epoxide, for this risk assessment. Concentrations of each pesticide were measured from randomly sampled vegetables. In order to estimate the human exposure levels, we combined the concentration of pesticides in the vegetables with consumption rate of those vegetables. Three scenarios were hypothesized for human exposure assessment. Scenario I was the most conservative which supposed the undetected CPs would be the detection limit values. Scenario II was assumed that the undetected CPs would be a half of the detection limit values, and finally scenario III merely considered only values greater than the detection limit values. We finally presented the estimated carcinogenic risks on the basis of the traditional risk assessment procedure suggested by U.S. EPA. Results: Pesticides including DDT, dieldrin, folpet and heptachlor epoxide were detected in 9 samples (6%) in the range of . The daily intake levels of carcinogenic pesticides were estimated in the range of . As we expected, excess cancer risks based on scenario I was also the highest . Conclusions: We found that the estimated risks from the pesticides we investigated were not serious. We, however, propose that a continuos monitoring is needed to make sure for the protection of public health.

The main purpose of applying the chlorination process during water treatment is for disinfection. Research results, however, indicate that disinfection by-products (DBPs) including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), haloketones (HKs), and chloropicrin (CP) can be produced by the chlorination process. Some of these DBPs are known to be potential human carcinogens. This 3-year project is designed to establish a standard analysis procedure for DBPs in drinking water of this country and investigate the distribution and sources of specific DBPs. The occurrence level of DBPs in drinking water was below 50 μg/l in most cases. THMs in plant effluent accounted for 60% of all DBPs measured, whereas HAAs accounted for 20%, HANs 12%, HKs 5% and CP 3%. Chloroform was found to be the major THMs compound (77%), followed by bromodichloromethane (BDCM, 18%) and bromoform (BF, 3%). The concentration of DBPs formed in distribution systems increased from those detected in plant effluent. Comparison of humic acid and sewage as precursors for THMs formation showed that humic acid was the major THMs precursor. Results would play an important role in exposure assessment as a part of the risk assessment process, and would give basic information for establishment of DBPs reduction and management procedures.

Objectives: To reexamine the association between air pollution and daily mortality in Seoul, Korea using a method of meta-analysis with the data filed for 1991 through 1995. Methods: A separate Poisson regression analysis on each district within the metropolitan area of Seoul was conducted to regress daily death counts on levels of each ambient air pollutant, such as total suspended particulates (TSP), sulfur dioxide , and ozone , controlling for variability in the weather condition. We calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. Results: We found that the p value from each pollutant model to test the homogeneity assumption was small (p increment in a 3-day moving average of TSP levels was 1.034 (95% Cl 1.009-1.059). The mortality was estimated to increase 6% (95% Cl 3-10%) and 3% (95% Cl 0-6%) with each 50 ppb increase for 9-day moving average of SO2 and 1-hr maximum O3, respectively. Conclusions: Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in a district-specific estimate since a monitoring station is hefter representative cf air quality of the matched district. The similar results to those from the previous studios indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

A large number of studies have indicated associations between particulate air pollution and daily mortality. Daily measurements of total suspended particulates (TSP) by high volume air sampler were matched to daily death counts supplied by the National Statistics Office, Korea. All deaths, except deaths from accidents, occurred at Ulsan from 1 January 1991 to 31 December 1994 were considered in the poisson regression analysis. The multiple regression models were used to investigate a main effects of air particulate pollution controlling for levels, air temperature, relative humidity, seasonal variation, and calendar year. The results indicated that the effects of TSP, , temperature, and relative humidity were not significantly associated with all cause mortality. It could, however, be emphasized that the size of the parameter estimate of TSP was very similar to that of previous studies. An increase in particulates of was associated with a 3% increase in mortality. This relationship was observed at TSP levels well below the current National Ambient Air Quality Standard of in Korea as well.

Biological Monitoring of Benzene in Residents living near Petrochemical Industrial Areas: Yoonho C hoi , et al . Department of Preventive Medicine and Public Health, Yonsei University, Korea —Residents who live near petrochemical industrial areas risk exposure to a variety of petrochemicals, including benzene and benzene‐containing liquids. It is a serious concern because benzene is a human carcinogen naturally present in petroleum and gasoline. The aim of this study was to assess the exposure to benzene, measured by personal/indoor/outdoor air sampling, and to estimate the relationship between the air samples and biological monitoring data. Through biological monitoring, we investigated s ‐phenylmercapturic acid (s‐PMA), minor urinary metabolites of benzene, and benzene in blood. The external benzene exposure of 115 subjects was measured with passive dosimeters and urinary s ‐PMA and blood‐benzene were determined by GC/MS. The mean concentration of benzene in the breathing zone of residents was 6.3 μg/m 3 , slightly higher than indoor or outdoor concentrations. Personal, indoor and outdoor concentrations of benzene were significantly correlated to each other. s ‐PMA was affected by personal exposure (p<0.05) and was differed according to age (p<0.01) and residence time (p<0.05). Blood benzene was not affected by external benzene during these periods.

The contamination of drinking water supply is becoming an increasingly serious problem in Korea. In order to protect public health, there is a need to regulate drinking water pollutants. The purpose of this project, a national project for three years starting from 1992 to 1995, is to assess the health risk of pollutants in drinking water and recommend guidelines and management plans for maintaining good quality of drinking water. This study was conducted to monitor 80 species of chemicals including volatile organic compounds(VOCs), polycyclic aromatic hydrocarbons(PAHs), pesticides and metals in six major rivers and their distribution system for drinking water in Korea, and evaluate health risk due to exposure to these chemicals through four main steps of risk assessment in drinking water. In hazard identification, 80 species of chemicals were identified by the US EPA classification system. In their steps of exposure assessment, sampling of raw, treated and drinking water from the public water supply system have been conducted from 1993 to 1995, and 80 chemicals were analyzed. In dose-response assessment, cancer potencies, unit risk estimates and virtual safety doses of carcinogens were obtained by TOX-RISK, and reference doses and lifetime health advisories of noncarcinogens were calculated. Finally, in the risk characterization of detected chemicals, health risk due to exposure to carcinogens (weight of evidence, A or B) such as vinyl chloride, carbon tetrachloride, 1,2-dichloroethane, benzen, 1,1,1,2-tetrachloroethane, trihalomethanes(THMs), lead and arsenic of tap water in several cities exceeded 10−5 level. We suggest that non-regulated chemicals such as vinyl chloride, carbon tetrachloride and 1,2-dichloroethane should be monitored periodically and be regulated by the Drinking Water Management Act.

To investigate the relationship between methyl jasmonate (MeJA) and ethylene in leaf senescence, we studied the effects of MeJA on ethylene production and ethylene biosynthetic enzyme activities in oat(Avena sativa L.) leaf segments incubated in darkness. MeJA promoted dark-induced senescence judged from the contents of chlorophyll and protein, and increased ethylene production 6 times of the control. MeJA also increased the activities of ethylene biosynthetic enzymes, 1-aminocyclopropane carboxylic acid (ACC) synthase and ACC oxidase as compared to control. In MeJA-treated leaf segments, ACC synthase activity reached its maximum level at 24 h of incubation and ACC oxidase activity peaked at 6 h of incubation. Aminoethoxyvinylglycine (AVG) and Co2+, inhibitors of ACC synthase and ACC oxidase respectively, reduced MeJA-induced ethylene production. They also delayed leaf senescence that was promoted by the treatment of MeJA. From these results, we can suggest that MeJA increased the activities of ACC synthase and ACC oxidase, these increased activities lead to increase in ethylene production and this increased ethylene production might promote dark-induced leaf senescence.

Kinetic studies on phosphorus (P as orthophosphate) sorption onto a sandy loam soil hom North Sydney, Australia, and a slag (waste products from the BHP steel industry, Australia) revealed that more than 90% of the P was adsorbed within 70 and 12 hours for the soil and slag respectively. The pH of the P solution played a critical role in the rate of P removal. Removal was at a minimum at pH 2. Dominant removal mechanism of P at pH less than 8 was physical sorption, while it was chemical precipitation at pH greater than 10. Adsorptive capacity of the slag was 225 and 53 times of that of the soil for the static and dynamic systems respectively. Breakthrough curves obtained from the column experiments are S-shaped and more spreaded with the decrease of influent P concentration. Simulated results from an equilibrium sorption model (ESM) and Freundlich isotherm constants did not always match the corresponding experimental breakthrough data. Mobility of P is restricted by the adsorbent due to its high sorption capacity of P.

This study described methods to predict human health risk associated with exposure to environmental carcinogens using animal bioassay data. Also, biological assumption for various dose-response models were reviewed. To illustrate the process of risk estimate using relevant dose-response models such as Log-normal, Mantel-Bryan, Weibull and Multistage model, we used four animal carcinogenesis bioassy data of chloroform and chloroform concentrations of tap water measured in large cities of Korea from 1987 to 1995. As a result, in the case of using average concentration in exposure data and 95% upper boud unit risk of Multistge model, excess cancer risk(RISK I) was about , in the case of using probability distribution of cumulative exposure data and unit risks, those risks(RISK II) which were simulated by Monte-Carlo analysis were about at 50 and 95 percentile, respectively. Therefore risk estimated by Monte-Carlo analysis using probability distribution of input variables may be more conservative.