Sung-Ok Baek

Indoor air quality in homes, offices and restaurants in Korean urban areas—indoor/outdoor relationships

Air quality monitoring was carried out to collect data on the levels of various indoor and ambient air constituents in two cities in Korea (Seoul and Taegu). Sampling was conducted simultaneously indoors and outdoors at six residences, six offices and six restaurants in each city during summer 1994 and winter 1994–1995. Measured pollutants were respirable suspended particulate matter (RSP), carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), and a range of volatile organic compounds (VOCs). In addition, in order to evaluate the effect of smoking on indoor air quality, analyses of parameters associated with environmental tobacco smoke (ETS) were undertaken, which are nicotine, ultraviolet (UVPM), fluorescence (FPM) and solanesol particulate matter (SolPM). The results of this study have confirmed the importance of ambient air in determining the quality of air indoors in two major Korean cities. The majority of VOCs measured in both indoor and outdoor environments were derived from outdoor sources, probably motor vehicles. Benzene and other VOC concentrations were much higher during the winter months than the summer months and were not significantly greater in the smoking sites examined. Heating and cooking practices, coupled with generally inadequate ventilation, also were shown to influence indoor air quality. In smoking sites, ETS appears to be a minor contributor to VOC levels as no statistically significant relationships were identified with ETS components and VOCs, whereas very strong correlations were found between indoor and outdoor levels of vehicle-related pollutants. The average contribution of ETS to total RSP concentrations was estimated to range from 10 to 20%.

Review on Analytical and Biological Applications of Hydrazones and their Metal Complexes

Hydrazones are very important group of analytical regents for the determination of various metal ions by using various analytical techniques. Besides this use of hydrazones are also having biological activities also. In this paper we first discussed about the chemical nature of hydrazones and their biological activities. We mainly focused on the papers which were published during 1980-2011 on analytical applications (spectrophotometric and spectrofluorimetric) of hydrazones. We gave the total established conditions for the determination of various metal ions with hydrazones.

A QUANTITATIVE ESTIMATION OF SOURCE CONTRIBUTIONS TO THE CONCENTRATIONS OF ATMOSPHERIC SUSPENDED PARTICULATE MATTER IN URBAN, SUBURBAN, AND INDUSTRIAL AREAS OF KOREA

The purpose of this study was to estimate the contributions of various sources to the suspended particulate matter (SPM) in the atmosphere of urban residential, suburban, and industrial areas of Korea. In this work, the techniques of principal component analysis (PCA) and stepwise multiple regression analysis were employed to identify and quantify the major sources which influence the ambient SPM. The mass contributions of the different sources were estimated by the calculation of absolute principal component scores (APCS), and a subsequent stepwise regression of the SPM concentrations using the APCS. The results indicated that the major classes of source which contribute to the ambient SPM in Korea are soil re-suspension, fuel combustion, motor vehicles, and secondary aerosols. The compilation of an extensive inventory of such sources is an essential task, so that a more detailed apportionment of their contributions to the SPM can be made in Korea.

Recent Developments in the Speciation and Determination of Mercury Using Various Analytical Techniques.

This paper reviews the speciation and determination of mercury by various analytical techniques such as atomic absorption spectrometry, voltammetry, inductively coupled plasma techniques, spectrophotometry, spectrofluorometry, high performance liquid chromatography, and gas chromatography. Approximately 126 research papers on the speciation and determination of mercury by various analytical techniques published in international journals since 2013 are reviewed.

Characterization of carbonyl compounds in the ambient air of an industrial city in Korea.

The purpose of this study was to characterize spatial and temporal variations of carbonyl compounds in Gumi city, where a number of large electronic-industrial complexes are located. Carbonyl samples were collected at five sites in the Gumi area: three industrial, one commercial, and one residential area. Sampling was carried out throughout a year from December 2003 to November 2004. At one industrial site, samples were taken every six days, while those of the other sites were for seven consecutive days in every season. Each sample was collected for 150 minutes and at intervals of three times a day (morning, afternoon, and evening). A total of 476 samples were analyzed to determine 15 carbonyl compounds by the USEPA TO-11A (DNPH-cartridge/HPLC) method. In general, acetaldehyde appeared to be the most abundant compound, followed by formaldehyde, and acetone+acrolein. Mean concentrations of acetaldehyde were two to three times higher in the industrial sites than in the other sites, with its maximum of 77.7 ppb. In contrast, ambient levels of formaldehyde did not show any significant difference between the industrial and non-industrial groups. Its concentrations peaked in summer probably due to the enhanced volatilization and photochemical reactivity. These results indicate significant emission sources of acetaldehyde in the Gumi industrial complexes. Mean concentrations of organic solvents (such as acetone+acrolein and methyl ethyl ketone) were also significantly high in industrial areas. In conclusion, major sources of carbonyl compounds, including acetaldehyde, are strongly associated with industrial activities in the Gumi city area.

Performance Evaluation of Simultaneous Monitoring of Personal Exposure to Environmental Tobacco Smoke and Volatile Organic Compounds

The objective of this study was to develop and demon strate a methodology to determine human exposure to a variety of indoor air contaminants by personal monitor ing. Target analytes included respirable suspended par ticulates, components of environmental tobacco smoke (ETS) and a wide range of volatile organic compounds (VOCs). A total of 60 non-smoking, non-occupational res idents at homes in metropolitan Taegu, Korea, were recruited for this study. The subjects were classified into two groups, i.e. subjects living in homes with smokers and without smokers. Seasonal air samples were col lected using three-channel personal samplers for each subject in two phases over a 24-hour period, i.e. awake time and sleeping time separately. Performance of sam pling and analytical methods used for the simultaneous measurements of ETS and VOCs were evaluated with respect to sensitivity, repeatability and field application.

Determination of heavy metals in the ambient atmosphere: A review

Heavy metal determination in ambient air is an important task for environmental researchers because of their toxicity to human beings. Some heavy metals (hexavalent chromium (Cr), arsenic (As), cadmium (Cd) and nickel (Ni)) have been listed as carcinogens. Furthermore, heavy metals in the atmosphere can accumulate in various plants and animals and enter humans through the food chain. This article reviews the determination of heavy metals in the atmosphere in different areas of the world since 2006. The results showed that most researchers concentrated on toxic metals, such as Cr, Cd, Ni, As and lead. A few studies used plant materials as bio-monitors for the atmospheric levels of heavy metals. Some researchers found higher concentrations of heavy metals surrounding industrial areas compared with residential and/or commercial areas. Most studies reported the major sources of the particulate matter and heavy metals in the atmosphere to be industrial emissions, vehicular emissions and secondary aerosols.

Speciation and determination of mercury by various analytical techniques

Abstract Mercury is one of the most important metals to environmental researchers due to its toxicity. In recent years, many authors determined the concentration of mercury and its different forms in the environment, such as soil, water, atmosphere and biota, with various analytical techniques, such as atomic absorption spectrometry, spectrophotometry, voltammetry, inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry, spectrofluorometry and chromatography. The objective of this paper is to summarize the recent understanding of the available techniques for the analysis and speciation of mercury in environmental and biological samples reported worldwide during 2010–2011. We tabulated all the analytical parameters of about 129 research papers published in reputable international journals during 2010–2011 about mercury determination and speciation studies.

Application of Adsorption Sampling and Thermal Desorption with GC/MS Analysis for the Measurement of Low-Molecular Weight PAHs in Ambient Air

Polycyclic aromatic hydrocarbons (PAHs) have been of particular concern since they are present both in the vapor and particulate phases in ambient air. In this study, a simple method was applied to determine the vapor phase PAHs, and the performance of the new method was evaluated with a conventional method. The simple method was based on adsorption sampling and thermal desorption with GC/MS analysis, which is generally applied to the determination of volatile organic compounds (VOCs) in the air. A combination of Carbotrap (300 mg) and Carbotrap-C (100 mg) sorbents was used as the adsorbent. Target compounds included two rings PAHs such as naphthalene, acenaphthylene, and acenaphthene. Among them, naphthalene was listed as one of the main HAPs together with a number of VOCs in petroleum refining industries in the USA. For comparison purposes, a method based on adsorption sampling and solvent extraction with GC/MS analysis was adopted, which is in principle same as the NIOSH 5515 method. The performance of the adsorption sampling and thermal desorption method was evaluated with respect to repeatabilities, detection limits, linearities, and storage stabilities for target compounds. The analytical repeatabilities of standard samples are all within 20%. Lower detection limits was estimated to be less than 0.1 ppbv. In the results from comparison studies between two methods for real air samples. Although the correlation coefficients were more than 0.9, a systematic difference between the two groups was revealed by the paired t-test (α=0.05). Concentrations of two-rings PAHs determined by adsorption and thermal desorption method consistently higher than those by solvent extraction method. The difference was caused by not only the poor sampling efficiencies of XAD-2 for target PAHs and but also sample losses during the solvent *Corresponding author. Tel : +82-(0)53-810-2544, E-mail : sobaek@yu.ac.kr 기술자료

Current Status and Prospective of Hazardous VOC in Ambient Air

In this article, we reviewed the monitoring status of hazardous VOC in ambinet air in Korea and some developed countries such as USA, Japan, and UK. In many countries, two types of VOC monitoring stations are being operated, i.e., for hazardous VOC and photochemical VOC. Each country has different target VOC but all includes benzene. Korea, Japan, and UK have a national ambient air quality standard for benzene, but no national standard has been established in the USA. For sampling of the hazardous VOC, the adsorbent method is adopted in Korea and UK, while the canister method is used in the USA. Both of adsorbent and canister methods are used in Japan. USA and UK have only non-automatic method to measure the hazardous VOC, and the individual samples are being sent to their national laboratories for integrated analysis. On the other hand, Korea and Japan have automatic and nonautomatic methods to measure the hazardous VOC. Local governments or regional environmental agencies in Korea and Japan have the authorization for the sampling and analysis of VOC. According to a field study to evaluate the performance of automatic VOC monitoring system, controlling the moisture in the air sample was identified as the most important problem. However, careful attention must be given to using a moisture removing device such as Nafyon dryer, because of unexpected artifacts formation. In order to have reliable data, it is highly recommended not only to use internal standards, but to use appropriate hydrophobic adsorbents as a cold trap in any automatic on-line VOC monitoring system.