Objectives: The pollution status of heavy metals within the soil was investigated with an aim to establishing a sustainable soil environment within parks and amusement facilities installed in urban areas of Gyeonggi-do Province.Methods: As sampling sites, 14 locations were selected from a city with a number of factories near a residential area, a residential area, and a children's park in a city with mixed green areas. Seven kinds of heavy metals, including Cd, Pb, and Hg, and the pH of soil were analyzed three times by inductively coupled plasma optical emission spectroscopy (ICP-OES) and atomic absorption spectrometer (AAS).Results: In this study, the pH of the samples from the residential park and industrial park showed 5.7-6.5 and 5.9-7.0, respectively. The overall mean concentration (mg/kg) of heavy metals was Zn (132.8), Ni (73.0), Cu (47.4), Pb (35.9), As (4.84), Cd (0.39), and Hg (0.07), indicating that these concentrations of heavy metals were lower than those for the area 1 standard of soil pollution concern criteria. In addition, the sampling sites in the residential area and the industrial area also showed the same tendency for concentration distribution.
Conclusions:We found that the soil pollution class (SPC) of some spots were over 200, which are third and fourth classes. In order to manage a sustainable soil environment in a city park, it is suggested that local governments, the management bodies for these parks, need to manage, supervise, and investigate soil pollution and quickly replace contaminated soil.
After establishment of Banwol industrial complex in 1987, Ansan city becomes the largest industrial sector development in Gyeonggi-do, Korea. As the population and industrial activity grow over this region, toxic air pollutants, particularly POPs (Persistent Organic Pollutants) from various emission sources have been major public concerns. Air samples for POPs monitoring were collected at the industrial sites (A 2 ), residential sites (B 1 , B 2 ), commercial site (C), and rural/remote site (D) of the area of Ansan during 2008 with a prolonged industrial sampling site A 1 from 2001 to 2008. All samples were analysed for 2,3,7,8 substituted-polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) and dioxin like polychlorinatd diphenyls (dl-PCBs).In site A 1 , a steady decline of their concentrations from 2003 to 2008 was observed due to the reinforced emission guideline from waste incinerators. The average concentration of the PCDD/Fs and dl-PCBs ranged between 0.118 pg-TEQ/m 3 (rural/remote site D) and 0.532 pg-TEQ/m 3 (industrial area A 2 ). These level were generally consistent with previous studies in Gyeonggi-do, while higher than other places. Most of PCDD/Fs congener were partitioned into particle phase, whereas dl-PCBs were partitioned into gas phase. The logarithm of gas-particle partition coefficient K P of dl-PCBs and PCDD/Fs were well correlated with sub-cooled liquid vapor pressure P L . The slope m T of log K P versus log P L for PCDD/Fs (-1.22) and dl-PCBs (-1.02) in industrial area (A 2 ) were high compared to other residential/commercial area. It suggests that this area was likely influenced by the direct emission source of PCDD/Fs and dl-PCBs. To simulate the partition of PCDD/Fs and dl-PCBs between gas and particle phase, Junge-Pankow model (P L -base) and K oa model were applied. It was found that J-P model was more suitable than the K oa model in this study.
Electrical properties and thermal annealing e f f ec ts of Czz-quinol ium ( TCNQ ) Langmui r -Blodge t t ( LB ) f i lms were studied. Typical current-voltage( I-V) characteristics along the perpendicular direction show an anomalous behavior of breakdown near the electric-field strength of 10' V/cm. From the study of I-V characteristics in the high-electric field region, it is found that there is a contribution of joule heating in addition to the electrical effect. To see the thermal influence of the specimen, current was measured as a function of temperature(20 -180C). It shows that the current increases about 4 orders of magnitude near 60 -70t, and remains constant for a while up to -150C and then suddenly drops. Such increase of current near 60 -70C seems to be related to a softness of alkyl chains. Besides the electrical measurements, W/visible absorption(300 -
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