• Asian Journal of Atmospheric Environment
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• v.7 no.2
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• pp.120-128
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• 2013

The concentration and composition of particulate matter (PM) in the atmosphere can directly reflect the environmental pollution. The atmospheric pollution in some Cameroonian cities is increasing with the industrial development and urbanization. Air pollution is inherently complex, containing PM of varied size and composition. This PM exists as a dynamic cloud interacting with sunlight and is modified by the meteorology. The reflectometer and the EDXRF spectrometry are applied to determine the concentration of some specific elements at four sites in the city of Yaound$\acute{e}$. The particular aim of the present work is to put in place data base on air pollution in urban area and elaborate regulations on the emissions issued to industrial and vehicle activities. This study provides an overview of the concentration of black carbon and some specific elements in the air, which have impacts on human health. The measurement was done by distinguishing the size of particle. So that, the particle with aerodynamic diameter between $2.5-10{\mu}m$ (so-called coarse particle) and aerodynamic diameter < $2.5{\mu}m$ (so-called fine particle) were considered to obtain more information about levels of the inhalable fraction of the location. The results obtained in four locations of the city of Yaound$\acute{e}$ show that the black carbon concentration is very considerable, the element sulfur is a major pollutant and the concentration of fine particle is very greater. The results obtained of fine and coarse filters range from $5-17{\mu}g/m^3$ and $10-18{\mu}g/m^3$ for the black carbon. S, Cu, Zn, Pb, Cd, As, Se and Hg are the specific findings of this work. The pollutants with a greater concentration are S, Pb, and Zn. These later seem to be non-uniformly, non-regular in some location and high compared to other countries. This work allows us to make a potential relation between pollutants and emission sources. In this framework, some suggestions have been proposed to reduce emissions for an improvement of the air quality in the environment and thus, the one of the city of Yaound$\acute{e}$.

• Journal of Environmental Impact Assessment
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• v.32 no.5
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• pp.269-278
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• 2023

The pollution status of heavy metals in the soils of children's playground was investigated for a sustainable soil environment in urban parks of Seoul. As sampling sites, 281 locations were selected from a 7 districts in the Seoul city. The overall mean concentrations of the heavy metals (Cd 0.21 mg/kg, Cu 5.97 mg/kg, As 2.40 mg/kg, Pb 7.55 mg/kg, Zn 34.08 mg/kg, Ni 4.22 mg/kg, Hg 0.02 mg/kg and Cr6+ not detected.) in the soils of the palygrounds were lower than the worrisome level in criteria for area 1 in Korea soil environment conservation act. In addition, when the soil pollution grade (SPC) was evaluated as an average value, it was found to be less than 100, the first grade, at all points in the seven autonomous districts, indicating thatthe soil was in good soil condition. However, when evaluated as the maximum value, some of the five districts showed values of 100 or more. Therefore, it was found that continuous management and interest of the local government, which is the management body of children's playgrounds, is necessary for a safe soil environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.118-128
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• 2005

Surface sediment samples from 31 stations in Jinhae Bay were analyzed to evaluate the pollution by sewage from the spatial distribution of the fecal sterol, coprostanol. The sums of eight sterols (coprostanol, epicholestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta$-sitosterol) were in the range of $2,703-27,154{\cal}ng/{\cal}g$ dry weight. The concentrations of the coprostanol in the sediments, which is a good tracer of sewage-derived organic contamination, were in the range of $76-3,964{\cal}ng/{\cal}g$ dry weight. The levels of coprostanol were much higher (almost one order of magnitude) at stations close to the big cities such as Masan and Jinhae. However, those levels were comparable to or lower than those previously reported in other foreign locations. Some ratios of coprostanol to other sterols and multivariate analysis could provide us with the information on the origin of the sterols being from sewage, plankton, and/or benthos. Those showed sewage dominance at the stations near the cities Masan and Jinhae, plankton dominance at the center of Jinhae Bay and mainly marine fauna origin at the mouth of Jinhae Bay. These results suggest that the contents of sterols and some ratios of these components are quite powerful tracer for the detection of the origin of the organic contaminants in the coastal environments.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.55-56
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• 2006

This thesis describes the use of measured aerosol size distributions and size-resolved hygroscopic growth to examine the physical and chemical properties of several particle classes. The primary objective of this work was to investigate the optical and cloud forming properties of a range of ambient aerosol types measured in a number of different locations. The tool used for most of these analyses is a differential mobility analyzer / tandem differential mobility analyzer (DMA / TDMA) system developed in our research group. To collect the data described in two of the chapters of this thesis, an aircraft-based version of the DMA / TDMA was deployed to Japan and California. The data described in two other chapters were conveniently collected during a period when the aerosol of interest came to us. The unique aspect of this analysis is the use of these data to isolate the size distributions of distinct aerosol types in order to quantify their optical and cloud forming properties. I used collected data during the Asian Aerosol Characterization Experiment (ACE-Asia) to examine the composition and homogeneity of a complex aerosol generated in the deserts and urban regions of China and other Asian countries. An aircraft-based tandem differential mobility analyzer was used for the first time during this campaign to examine the size-resolved hygroscopic properties of particles having diameters between 40 and 586 nm. Asian Dust Above Monterey (ADAM-2003) study was designed both to evaluate the degree to which models can predict the long-range transport of Asian dust, and to examine the physical and optical properties of that aged dust upon reaching the California coast. Aerosol size distributions and hygroscopic growth are measured in College Station, TX to investigate the cloud nucleating and optical properties of a biomass burning aerosol generated from fires on the Yucatan Peninsula. Measured aerosol size distributions and size-resolved hygroscopicity and volatility were used to infer critical supersaturation distributions of the distinct particle types that were observed during this period. The predicted CCN concentrations were used in a cloud model to determine the impact of the different aerosol types on the expected cloud droplet concentration. RH-dependent aerosol extinction coefficients are calculated at a wavelength of 550 nm.

• Asian Journal of Atmospheric Environment
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• v.12 no.2
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• pp.165-177
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• 2018

Particulate matter (PM) measurements are important in air quality, public health, epidemiological studies and decision making for short and long-term policies implementation. However, only few cities in the word have advance air quality-monitoring networks able to provide reliable information of PM leaves in the ambient air, trends and extent of the pollution. In Colombia, only major cities measure PM concentrations. Available measurements from Bogota, Medellin and Bucaramanga show that PM concentration are well above World Health Organization guidelines, but up to now levels and trends of PM in other cities and regions of the country are not well known. Satellite measurements serve as an alternative approach to study air quality in regions were surface measurements are not available. The aim of this study is to perform a spatial and temporal assessment of PM in the ambient air of Colombia. We used Aerosol optical depth (AOD) retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite of NASA and surface measurements from the air quality networks of Bogota, Medellin and Bucaramanga. In a first step, we estimated the correlation between MODIS-AOD and monthly average surface measurements (2000 to 2015) from these three cities, obtaining correlation coefficient R values over 0.4 for the cities under study. After, we used AOD and $PM_{10}$ measurements to study the temporal evolution of PM in different cities and regions. Finally, we used AOD measurements to identify cities and regions with the highest AOD levels in Colombia. All the methods presented in this paper may serve as an example for other countries or regions to identify and prioritize locations that require the implementation of more accurate air quality measurements.

• Toxicological Research
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• v.29 no.1
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• pp.69-79
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• 2013

The purpose of this study was to investigate the current status of metal pollution in the sediment from rivers, lakes, and streams in active gold mining districts in Ghana. Two hundred and fifty surface sediment samples from 99 locations were collected and analyzed for concentrations of As, Hg, Cr, Co, Cu, Fe, Zn, Pb, Cd, Ni, and Mn using inductively coupled plasma-mass spectroscopy (ICP-MS). Metal concentrations were then used to assess the human health risks to resident children and adults in central tendency exposure (CTE) and reasonable maximum exposure (RME) scenarios. The concentrations of Pb, Cd, and As were almost twice the threshold values established by the Hong Kong Interim Sediment Quality Guidelines (ISQG). Hg, Cu, and Cr concentrations in sediment were 14, 20, and 26 times higher than the Canadian Freshwater Sediment Guidelines for these elements. Also, the concentrations of Pb, Cu, Cr, and Hg were 3, 11, 12, and 16 times more than the Australian and New Zealand Environment and Conservation Council (ANZECC) sediment guideline values. The results of the human health risk assessment indicate that for ingestion of sediment under the central tendency exposure (CTE) scenario, the cancer risks for child and adult residents from exposure to As were $4.18{\times}10^{-6}$ and $1.84{\times}10^{-7}$, respectively. This suggests that up to 4 children out of one million equally exposed children would contract cancer if exposed continuously to As over 70 years (the assumed lifetime). The hazard index for child residents following exposure to Cr(VI) in the RME scenario was 4.2. This is greater than the United States Environmental Protection Agency (USEPA) threshold of 1, indicating that adverse health effects to children from exposure to Cr(VI) are possible. This study demonstrates the urgent need to control industrial emissions and the severe heavy metal pollution in gold mining environments.

• Journal of Environmental Science International
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• v.14 no.6
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• pp.583-596
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• 2005

Samples of water, soil, and sediment were taken from 10 streams of Andong city in Gyeongbuk province in October 2004. To assess the degree of environmental pollution for each stream site, the chemical analyses of pollutants such as T-N, T-P, COD, heavy metal, organophosphorous and organochlorine pesticides, and dioxin-like PCB congeners were implemented using the standard process tests or the U. S. EPA methods. In addition, biological assessment using insect immune biomarkers was conducted on the same environmental samples to complement the chemical assessment. Except Waya stream (T-N; 2.91 mg/L, T-P; 0.16 mg/L, COD; 14.0 mg/L) with above the environmental quality standards, the T-P and COD concentrations of 9 sites are relatively low. The contents of Pb and Cd in samples taken from each stream were much lower than environmental quality standards. However, in comparison with soil samples of other streams, several times higher concentrations of Pb and Cd were found in locations at Mi, Gilan, Yeonha, and Waya stream sites. Dementon-S-methyl, diazinon, parathion, and phenthoate compounds among organophosphorous pesticides were detected as concentrations of ppb levels, respectively, from soil samples collected in the vicinity of Gilan, Mi, Norim, and Waya stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners selected in this study were not found in all samples. In particular, considering significant disrupting effects of Waya stream's samples on insect immune capacity, this stream seems to be contaminated with investigated and/or univestigated pollutants in this study.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.51-60
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• 2017

In this study, the concentrations of As, Cd, Cu, Pb and Zn in agricultural soils across a region of South Korea (Buyeo County) were investigated. Their pollution sources were assessed using multivariate statistical analysis, and Geographic Information System (GIS) technology was used to determine the distribution of these elements. Surface soil samples were collected from 114 locations across the agricultural fields in the study site. Cu and Zn were derived from natural sources (i.e., parent rocks of the soil), whereas As, Cd, and Pb were found to be originated from abandoned mines. The results of this study clearly show that the transport of anthropogenic As, Cd, and Pb is governed mostly by the specific environment of the paddy soil. Our approach was effective in clearly identifying the sources of metals and analyzing their contamination characteristics. We believe this study will provide useful information to future studies on soil pollution by anthropogenic sources.

• Economic and Environmental Geology
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• v.36 no.2
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• pp.89-101
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• 2003

River deposits and farmland soils were analyzed to investigate the pollution level of heavy metals in the vicinity of the Goro abandoned Zn-mine. Surface (0-40 cm) and subsurface (40-100 cm) soils were collected around a main river located at the lower part of the Goro mine, and analyzed by ICP-MS for Cd, Cu, Pb, Zn and Cr after 0. 1N HCI extraction and by AAS for As after IN HCI extraction. Concentrations of cadmium and lead at the surface river deposits close to the mine were over the Soil Pollution Warning Limit (SPWL), and 43% of sample sites (6 of 14 samples) were over SPWL for As suggesting that river deposits were broadly contaminated by arsenic. Results from farmland soil analysis showed that surface soils were contaminated by heavy metals, while only arsenic was over SPWL at 50% of sampling sites. Main pollution mechanism around the Goro mine was the discharge of mine tailing and waste rocks from the storage site to the river and to adjacent farmland during flood season. Pollution Grades for sample locations were prescribed by the Law of Soil Environmental Preservation, suggesting that the pollution level of heavy metals around the Goro mine was serious, and the remediation operation fur arsenic and the isolation of mine tailing and waste rocks from river and farmland should be activated to protect further contamination. The area needed to clean up was estimated from pollution distribution data and the remediation methods such as a soil washing method and a soil improvement method were considered as the further remediation operation for arsenic contaminated soils and river deposits around the Goro abandoned mine.

• Economic and Environmental Geology
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• v.36 no.6
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• pp.457-467
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• 2003

Soil Precise Investigation(SPI) for river deposits and farmland soils around Goro abandoned Zn-mine, Korea was performed to assess the pollution level of heavy metals(As. Pb, Cd, Cu) and to estimate the remediation volume for contaminated soils. Total investigation area was about 950000 $m^2$, which was divided into each section of 1500 $m^2$ corresponding to one sampling site and 545 samples for surface soil(0-10cm in depth) and 192 samples for deep soil(10-30cm in depth) from the investigation area were collected for analysis. Concentrations of Cu, Cd, Pb at all sample sites were shown to be lower than Soil Pollution Warning Limit(SPWL). For arsenic concentration, in surface soils, 20.5% of sample sites(104 sites) were over SPWL(6mg/kg) and 6.7%(34 sites) were over Soil Pollution Counterplan Limit(SPCL: 15mg/kg) suggesting that surface soils were broadly contaminated by As. For deep soils, 10.4% of sample sites(18 sites) were over SPWL and 0.6%(1 site) were over SPCL. Four pollution grades for sample locations were prescribed by the Law of Soil Environmental Preservation and Pollution Index(PI) for each soil sample was decided according to pollution grades(over 15.0 mg/kg, 6.00-15.00 mg/kg, 2.40-6.00 mg/kg, 1.23-6.00 mg/kg). The pollution contour map around Goro mine based on PI results was finally created to calculate the contaminated area and the remediation volume for contaminated soils. Remediation area with over SPWL concentration was about 0.3% of total area between Goro mine and a projected storage dam and 0.9% of total area was over 40% of SPWL. If the remediation target concentration was determined to over background level concentration, 1.1% of total area should be treated for remediation. Total soil volume to be treated for remediation was estimated on the assumption that the thickness of contaminated soil was 30cm. Soil volume to be remediated based on the excess of SPWL was estimated at 79,200$m^3$, soil volume exceeding 40% of SPWL was about 233,700 $m^3$, and soil volume exceeding the background level(1.23 mg/kg) was 290,760 TEX>$m^3$.