• Asian Journal of Atmospheric Environment
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• 제12권1호
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• pp.67-77
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• 2018

To investigate the effects of forest and the surrounding natural and anthropogenic sources on the bulk depositions on forested land, this study examined differences in ion concentrations between wet-only and bulk samples at two forested sites in Japan. The surrounding natural and anthropogenic sources at each site were different; Shirasaka is in a rural area and Tanashi is an urban environment. The volume weighted (vw) mean concentrations of $K^+$ and $Ca^{2+}$ in the bulk samples were significantly (p<0.05) higher than those in the wet-only samples at both sites. The forest canopy and a nearby incineration plant were hypothesized to be the main sources of $K^+$ contaminants at Shirasaka and Tanashi, respectively. The transport of sea salt and urban dust may explain the presence of enriched $Ca^{2+}$ concentrations in the bulk samples at Shirasaka and Tanashi, respectively. The $NH_4{^+}$ concentrations in the Shirasaka bulk samples were significantly (p<0.05) lower than those in the wet-only samples. The vw mean $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations in both sample types were not significantly different at either site. This study demonstrated that the ion concentration differences between wet-only and bulk samples were affected by nearby natural and anthropogenic sources even at forest sites, similar to previous findings for non-forested locations. However, the $K^+$ concentration differences between wet-only and bulk samples may be higher owing to forest sources, even in the absence of anthropogenic sources.

• 대기
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• 제29권5호
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• pp.567-583
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• 2019

In this study, the high-resolution numerical simulations considering detailed anthropogenic heat, albedo, emission and roughness length are analyzed by using single layer Urban Canopy Model (UCM) in Weather Research Forecast (WRF). For this, improved urban parameter data for Seoul Metropolitan Area (SMA) was collected from global data. And then the parameters were applied to WRF-UCM model after it was processed into 2-dimensional topographical data. The 6 experiments were simulated by using the model with each parameter and verified against observation from Automated Weather Station (AWS) and flux tower for the temperature and sensible heat flux. The data for sensible heat flux of flux towers on Jungnang and Bucheon, the temperature of AWS on Jungnang, Gangnam, Bucheon and Neonggok were used as verification data. In the case of summer, the improvement of simulation by using detailed anthropogenic heat was higher than the other experiments in sensible flux simulation. The results of winter case show improved in all simulations using each advanced parameters in temperature and sensible heat flux simulation. Improvement of urban parameters in this study are possible to reflect the heat characteristics of urban area. Especially, detailed application of anthropogenic heat contributed to the enhancement of predicted value for sensible heat flux and temperature.

• 한국환경농학회지
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• 제41권4호
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• pp.344-354
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• 2022

BACKGROUND: Although antibiotics have contributed to treatment of bacterial infection, the antibiotic abuse can lead to antibiotic resistant bacteria. Impact of human activities on distribution of antibiotic resistance has been intensively issued and occurrence of antibiotic resistant bacteria in contaminated environments would not be a surprise. Nonetheless, anthropogenic contamination with the dissemination of antibiotic resistance along uncontaminated environments has been less considered. The aim of this study is to investigate antibiotic resistant bacteria across Ulleungdo, known as antibiotic resistance free and anthropogenic pollution free environment in Rep. of Korea. METHODS AND RESULTS: Antibiotic resistant bacteria in coastal seawater of Ulleungdo were investigated in July 2021. Antibiotic susceptibility test using the disk diffusion method was applied with six drugs according to the Clinical and Laboratory Standards Institute (CLSI) guideline. Total 43 bacterial isolates were tested and 20 isolates among of them showed multidrug resistance. Particularly, the number and ratio of resistant bacteria were relatively high in a densely populated area of Ulleungdo. The bacterial communities were investigated using 16S rRNA gene metabarcoding approach in the coastal seawater and soils of Ulleungdo. In the bacterial communities, Firmicutes were selectively distributed only in seawater, suggesting the possibility of anthropogenic contamination in coastal seawater of Ulleungdo. CONCLUSION(S): We found antibiotic resistant bacteria in a populated area of Ulleungdo. The occurrence of antibiotic resistant bacteria in Ulleungdo seems to result from the recent anthropogenic impact. Consistent monitoring of antibiotic resistant bacteria in the uncontaminated environment needs to considered for future risk assessment of antibiotics.

• 대기
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• 제17권4호
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• pp.483-492
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• 2007

The objective of this study is to describe scientific progresses in understanding of climate change in the Intergovernmental Panel on Climate Change (IPCC) assessment reports, contributed by Working group I. Since 1988, IPCC's four assessment reports showed significant improvements in understanding of observed climate change, drivers of climate change, detection and attribution of climate change, climate models, and future projection. The results are based on large amounts of observation data, sophisticated analyses of data, improvements of climate models and the simulations. While the First Assessment Report (FAR) in 1990 reported that a detectable anthropogenic influence on climate has little observational evidence, the Fourth Assessment Report (AR4) reported that warming of the climate system is unequivocal and is very likely due to human influences. It is also noted that anthropogenic warming and sea level rise would continue for centuries due to the time scales associated with climate processes and feedbacks, even if greenhouse gas were to be stabilized.

• 환경영향평가
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• 제21권5호
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• pp.665-681
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• 2012

This study investigates the influence of anthropogenic heat (AH) release on urban boundary layer in the Gyeong-In region using the Weather Research and Forecasting model that includes the Seoul National University Urban Canopy Model (SNUUCM). The gridded AH emission data, which is estimated in the Gyeong-In region in 2002 based on the energy consumption statistics data, are implemented into the SNUUCM. The simulated air temperature and wind speed show good agreement with the observed ones particularly in terms of phase for 11 urban sites, but they are overestimated in the nighttime. It is found that the influence of AH release on air temperature is larger in the nighttime than in the daytime even though the AH intensity is larger in the daytime. As compared with the results with AH release and without AH release, the contribution of AH release on urban heat island intensity is large in the nighttime and in the morning. As the AH intensity increases, the water vapor mixing ratio decreases in the daytime but increases in the nighttime. The atmospheric boundary layer height increases greatly in the morning (0800 - 1100 LST) and midnight (0000 LST). These results indicate that AH release can have an impact on weather and air quality in urban areas.

• 한국대기환경학회지
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• 제17권3호
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• pp.277-288
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• 2001

Continuous atmospheric CO$_2$measurements measured during the 1 year(1998.8∼1999.8) at Korea Global Atmosphere Watch Observatory (KGAWO) in Anmyeon-do are analyzed by the selecting method which is recommended by WDCGG to get background CO$_2$. This method can reject data based on two criteria: the instability of CO$_2$ concentration within 1 hour from hourly standard deviation (hourly variability$\leq$ 0.6 ppm first selection) and the large changes in the CO$_2$ concentration from one hour to the nex(∼$\leq$0.3 ppm, second selection). We could obtain hourly background CO$_2$ of 37% in first selection and 20% in second selection during the l year. That are a little less than those of Ryori station in Japan. especially, the cases of background CO$_2$ which is selected were few during the summer. That is caused by affection of vegetation and anthropogenic source. After the selecting methods are applied, the cases which is selected for easterly wind decrease remarkably according to the analysis of wind direction about continuous CO$_2$ .That was affected by anthropogenic source from the east area.

• 수산해양교육연구
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• 제28권3호
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• pp.831-840
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• 2016

Hydrodynamic condition can be used to predict particle movement within water column and the results used to optimize environmental conditions for effective site selection, setting of environmental quality standard, waste dispersion, and pathogen transfer. To predict the extent of movement of particle from land, 3D hydrodynamic model that includes particle tracking module was applied to Geoje Bay and to calibrate particle tracking model, floating buoy measurement is operated. The model results show that short time is required for particles released into system from river to be transported to the shellfish farming area. It takes about 2 days for the particles to shellfish farming area under mean flow condition. It meant Geoje Bay, especially shellfish farming area is vulnerable to anthropogenic waste from river.

• Ocean and Polar Research
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• 제24권3호
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• pp.279-287
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• 2002

Successive 24 snow samples, collected from a 1.2m snow pit at a site on the summit of Main Dome in King George Island, Antarctic Peninsula, were measured for heavy metals such as Pb, Cd, Cu, and Zn and other chemical species. The mean concentrations of heavy metals are 3.48pg/g for Pb, 0.10pg/g for Cd, 16.6 pg/g for Cu and 15.8 pg/g for Zn, respectively. Pb and Cd concentrations observed in our samples are very comparable to those reported for recent snow at other Antarctic sites, while Zn and Cu levels are much higher than those at other sites. The annual fallout fluxes of all heavy metals approximately calculated are, however, much greater in King George Island than at other sites. With respect to the estimates of natural contributions, sea salt spray is found to be a major contributor to Cd and Zn inputs to the snow and minor to Cu inputs. On the other hand, the anthropogenic input can account for a large part of Pb concentrations. A tentative estimate represents that local emissions could be responsible for more than half of the excess Pb flux to the snow in King George Island.

• 한국대기환경학회지
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• 제17권6호
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• pp.463-474
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• 2001

In this study, the concentrations of major anthropogenic volatile organic compounds(VOCs) which include benzene, toluene, m, p-xylene, o-xylene, and ethylbenzene were measured at the Nan-ji-do landfill site during the spring and fall season of 2000. the temporal distribution characteristics of these VOCs were investigated over varying time scale. According to our study, the mean concentration of those species were computed to be 1.65$\pm$2.68(benzene), 9.62$\pm$9.32(toluene), 1.84$\pm$2.90(m, p-xylene), 0.83$\pm$1.43(o-xylene), and 1.17$\pm$1.21 ppb(ethylbenzene). The VOCs levels in the study area are not distinctively higher than the level typically found in urban area that can be subject to the influence of various anthropogenic source processes. Inspection of their temporal trends exhibited various patterns for the diurnal(and seasonal) cycle. Although each species showed distinctive patterns in temporal distribution trends, we were able to find the strong correlations among most concurrently measured VOCs except for benzene.

• 수산해양교육연구
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• 제28권4호
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• pp.1143-1151
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• 2016

To study the dispersion process and residence time of anthropogenic pollutant in Masan bay, a three-dimensional hydrodynamic model coupled to a particle tracking model, EFDC, is applied. Particle tracking model simulated the instantaneous release of particles emulating discharge from river and wastewater treatment plant to show the behaviour of pollutant in terms of water circulation and water exchange. Modelled outcomes for water circulation were in good agreement with tidal elevation and current data. The results of particle tracking model show that over half of particles released from northern Masan bay transport to out of area while the particles from Dukdong wastewater treatment plant transport to northern area. This meant pollution source from inside and outside of the northern area can affect water quality of northern Masan bay.