Assessment of Human Health Risk of Dioxin in Korea

This study assessed the daily exposure to dioxin using comparable approach methods in order to predict the human health risks of dioxin on the general adult population and incinerator workers in Korea. The health risk assessment of dioxin involved four scenarios (General-Direct, General-Breast Milk, General-Blood, and Worker-Blood). The risks were described in terms of the excess cancer risk and the MOEs (Margin-Of-Exposure) for cancer, reproductive dysfunctions, endometriosis, and neurobehavioral effects. The adult daily intake (General-Direct) of dioxin was estimated to be 0.50 pg-TEQ/kg-day based on the dioxin concentrations in the environmental media and foods in Korea. The average dioxin concentrations in General-Breast Milk, General-Blood, and Worker-Blood were 15.13 pg-TEQ/g fat, 14.57 pg-TEQ/g lipid, and 22.90 pg-TEQ/g lipid, respectively. The lifetime average daily doses (LADDs) of dioxin for General-Breast Milk, General-Blood, and Worker-Blood were estimated to be 1.35 pg-TEQ/kg day, 0.99 pg-TEQ/kg day, and 1.15 pg-TEQ/kg day, respectively. Although the estimated risks of cancer and reproductive dysfunctions were not unusually high in any of the four scenarios, the MOE values for the neurobehavioral effects on infants were not sufficiently high to guarantee the safety against this endpoint.     

Seasonal Variation of Chemical Composition in Fine Particles at Gosan, Korea

PM_2.5 aerosol samples were collected at Gosan in Jeju Island during six intensive measurement periods between November 2001 and August 2003. In order to investigate the chemical composition of fine particles, major ion components, trace elements, and elemental and organic carbon were analyzed. Quite different seasonal characteristic in the chemical composition of fine particles was observed. The concentration of most secondary aerosol components showed a summer minimum and a winter maximum with higher correlation between them at Gosan. This fact clearly reveals the possibility of long-range transport of such pollutants in winter. On the other hand, OC and EC had the highest concentration and good correlation with ion components, such as K⁺, Ca²⁺ in fall. It means that biomass burning could significantly influence the ambient fine carbonaceous particulate in fall, which was primarily long-range transported.     

Evaluation of Potential Molecular Markers for Urban Stormwater Runoff

Source specificity and persistence of several sulfur-polycyclic aromatic hydrocarbons (S-PAHs), nitro-PAHs (N-PAHs), and triphenylene were examined via analyses of stormwater runoff and wastewater effluent samples and spiked samples upon exposure to sunlight. Samples were collected during the 1997/1998 wet weather season from two major storm channels and four major wastewater treatment plants in southern California. Among the target compounds examined, 2-(4-morpholinyl)benzothiazole, dibenzothiophene, and triphenylene/chrysene were detected in storm runoff only. However, 2-(4-morpholinyl)benzothiazole appeared to degrade rapidly in seawater and sediment after sunlight exposure, which might impede its use as a runoff indicator. Dibenzothiophene and triphenylene also degraded quickly in sunlight-exposed seawater samples, but remained fairly abundant in sediments after six months of exposure to sunlight. They are by far the most promising candidates of urban runoff markers based on the criteria of abundance, source specificity, and persistence, although more research efforts are needed to ensure that no other sources would also contribute significantly to their presence in the aquatic environment.     

Landscape Equivalency Analysis: Methodology for Estimating Spatially Explicit Biodiversity Credits

We propose a biodiversity credit system for trading endangered species habitat designed to minimize and reverse the negative effects of habitat loss and fragmentation, the leading cause of species endangerment in the United States. Given the increasing demand for land, approaches that explicitly balance economic goals against conservation goals are required. The Endangered Species Act balances these conflicts based on the cost to replace habitat. Conservation banking is a means to manage this balance, and we argue for its use to mitigate the effects of habitat fragmentation. Mitigating the effects of land development on biodiversity requires decisions that recognize regional ecological effects resulting from local economic decisions. We propose Landscape Equivalency Analysis (LEA), a landscape-scale approach similar to HEA, as an accounting system to calculate conservation banking credits so that habitat trades do not exacerbate regional ecological effects of local decisions. Credits purchased by public agencies or NGOs for purposes other than mitigating a take create a net investment in natural capital leading to habitat defragmentation. Credits calculated by LEA use metapopulation genetic theory to estimate sustainability criteria against which all trades are judged. The approach is rooted in well-accepted ecological, evolutionary, and economic theory, which helps compensate for the degree of uncertainty regarding the effects of habitat loss and fragmentation on endangered species. LEA requires application of greater scientific rigor than typically applied to endangered species management on private lands but provides an objective, conceptually sound basis for achieving the often conflicting goals of economic efficiency and long-term ecological sustainability.     

INTEGRATING LANDSCAPE ASSESSMENT AND HYDROLOGIC MODELING FOR LAND COVER CHANGE ANALYSIS1

ABSTRACT: Significant land cover changes have occurred in the watersheds that contribute runoff to the upper San Pedro River in Sonora, Mexico, and southeast Arizona. These changes, observed using a series of remotely sensed images taken in the 1970s, 1980s, and 1990s, have been implicated in the alteration of the basin hydrologic response. The Cannonsville subwatershed, located in the Catskill/Delaware watershed complex that delivers water to New York City, provides a contrast in land cover change. In this region, the Cannonsville watershed condition has improved over a comparable time period. A landscape assessment tool using a geographic information system (GIS) has been developed that automates the parameterization of the Soil and Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS) hydrologic models. The Automated Geospatial Watershed Assessment (AGWA) tool was used to prepare parameter input files for the Upper San Pedro Basin, a subwatershed within the San Pedro undergoing significant changes, and the Cannonsville watershed using historical land cover data. Runoff and sediment yield were simulated using these models. In the Cannonsville watershed, land cover change had a beneficial impact on modeled watershed response due to the transition from agriculture to forest land cover. Simulation results for the San Pedro indicate that increasing urban and agricultural areas and the simultaneous invasion of woody plants and decline of grasslands resulted in increased annual and event runoff volumes, flashier flood response, and decreased water quality due to sediment loading. These results demonstrate the usefulness of integrating remote sensing and distributed hydrologic models through the use of GIS for assessing watershed condition and the relative impacts of land cover transitions on hydrologic response.     

The Indian Ocean tsunami and private donations to NGOs

Non‐governmental organisations (NGOs) are widely believed to raise their flag in humanitarian hotspots with a strong media presence in order to attract higher private donations. We assess this hypothesis by comparing the changes in donations between US‐based NGOs with and without aid operations in the four countries most affected by the tsunami in the Indian Ocean in 2004. Simple before‐after comparisons tend to support the hypothesis that ‘flying the flag’ helps attract higher private donations. However, performing a difference‐in‐difference‐in‐differences (DDD) approach, we find only weak indications that private donors systematically and strongly preferred NGOs with operations in the region. Extended specifications of the baseline regressions reveal that our major findings are robust. NGO heterogeneity matters in some respects, but the DDD results hold when accounting for proxies of the NGOs’ reputation and experience.     

Comparing Onsite and Offsite Methods for Measuring Norms for Trail Impacts

This study examined the comparability of onsite and offsite methods for measuring norms for trail impacts using photo/survey techniques. A total of 449 subjects participated in a study of Mudeung-Mountain Provincial Park, Gwang-Ju, Korea. For the overall photo evaluation method (OPEM), respondents rated the acceptability of bare soil area for each of a series of photographs. For the specific photo evaluation method (SPEM), respondents selected a photograph that illustrated the largest acceptable proportion of bare soil area from a series of 10 photographs. Overall, there were no substantial differences in maximum acceptable impacts between onsite (onsite-I visitor group surveyed at the actual trail points and onsite-II departing visitor group surveyed at the exit area) and offsite (students surveyed in a laboratory setting) groups for the two norm measurement alternatives (OPEM and SPEM). Subjects’ difficulty ratings were low for both methods, and there were no substantial differences in norms between individuals with high and low levels of experience at the park. The offsite method appears to be substitutable for onsite methods in this particular study area, which is a frontcountry setting with a relatively simple range of recreation opportunities. Implications and further studies are discussed.     

Effect of plasticizer dosage on properties of multiple recycled aggregate concrete

Journal of Material Cycles and Waste Management - Recently, studies on multiple recycling of concrete have been attracting attention. In general, multiple recycling increases adhered mortar content...     

Study to improve the reactivity of magnesium cations to CO2 for carbon capture and utilization technology using edible salt manufacturing plant wastewater

Journal of Material Cycles and Waste Management - This study aims to improve the formation of MgCO3 via inorganic carbon capture utilization (CCU) technology using industrial wastewater from an...     

Experimental investigation and optimization of dimple-roughened impinging jet solar air collector using a novel AHP-MABAC approach

Environmental Science and Pollution Research - The effect of the flow and geometric parameters of a dimple-roughened absorber plate on the enactment of solar air collectors (SACs) with air-impinged...