Integrated estuary management for diffused sediment pollution in Dapeng Bay and neighboring rivers (Taiwan)

This work investigated sediment samples collected from Dapeng Bay and three neighboring rivers (Kaoping River, Tungkang River, and Lingbeng River) in southwestern Taiwan, Republic of China. Multivariate statistical analysis techniques, i.e., factor analysis, cluster analysis, and canonical discriminant analysis were used for the evaluation of spatial variations to determine the types of pollution and to identify pollutant sources from neighboring rivers. Factor analysis results showed that the most important latent factors in Dapeng Bay are soil texture, heavy metals, organic matter, and nutrients factors. Contour maps incorporating the factor scores showed heavy metals accumulate along the lakesides, especially on the southeastern banks of the lakes. A cluster analysis was performed using factor scores computed from these latent factors. We then classified these areas into five distinct classes using sampling stations, and we illustrate that in the three river classes, the sediment properties are influenced by industrial and domestic wastewater and agricultural activities (including livestock rearing and farm activities). However, in Dapeng Bay, the rivers were influenced more by complicated biogeochemical processes; these could be identified as a type of pollution. Canonical discriminant analysis illustrated that two constructed discriminant functions made a marked contribution to most of the discriminant variables, and the significant parameters of porosity and Cd, Cr, Al, and Pb content were combined as the ??heavy metal factor??. The recognition capacities of the two discriminant functions were 82.6% and 17.4%, respectively. It is also likely that the annual mean of the water exchange rate is insufficient (taking about 7 days to eliminate pollutants) and therefore has significantly influenced the carbon and nutrient biogeochemical processes and budgets in the semi-enclosed ecosystem. Thus, the sediment properties are not similar between the lagoon and the neighboring rivers. Our results yield useful information concerning estuary recovery and water resources management and may be applicable to other basins with similar characteristics that are experiencing similar coastal environmental issues.     

Carbon fixation efficiency of plants influenced by sulfur dioxide

In the land ecosystem, the forest can absorb the carbon dioxide (CO₂) in the atmosphere and turn the CO₂ into organic carbon to store it in the plant body. About 2 × 10¹¹ tons of CO₂ changes through photosynthesis into organic matter by plant annually. In this research, ten kinds of woody plants were selected for assessing the carbon fixation ability influenced by sulfur dioxide (SO₂). The tested trees were put into a fumigation chamber for 210 days in a 40-ppb SO₂ environment. The results of this study showed that there was no clear symptom of tested trees under a 40-ppb SO₂ environment. The tested trees could tolerate this polluted environment, but it will impact their CO₂ absorption ability. The carbon fixation ability will reduce as the polluted period lengthens. The carbon fixation potential of tested trees ranged from 2.1 to 15.5 g·CO₂/m²·d with an average of 7.7 g·CO₂/m²·d. The changes in CO₂ absorption volume for Messerschmidia argentea were more stable during the fumigation period with a variation of 102%. Among the tested trees, Diospyros morrisiana had the best carbon fixation potential of 9.19 g·CO₂/m²·d and M. argentea had the least with 2.54 g·CO₂/m²·d.     

Development of a Local-Scale Spatially Refined Multimedia Fate Model (LSRMFM) for Urban-Scale Risk Assessment: Model Formulation, GIS-Based Preprocessing, and Case Study

A local-scale spatially refined multimedia fate model (LSRMFM) was developed to evaluate in detail the multimedia transport of organic compounds at a spatial level. The model was derived using a combination of an advection?Cdispersion?Creaction partial differential equation, a steady-state multimedia fugacity model, and a geographical information system. The model was applied to predicting four major volatile organic compounds that are produced as emissions (benzene, toluene, xylene, and styrene) in an urban and industrial area (the 50?×?50-km area was divided into 0.5?×?0.5-km segments) in Korea. To test the accuracy of the model, the LSRMFM was used to predict the extent of dispersion and the data compared with actual measured concentrations and the results of a generic multimedia fate model (GMFM). The results indicated that the method developed herein is appropriate for predicting long-term multimedia pollution. However, the comparison study also illustrated that the developed model has some limitations (e.g., steady-state assumption) in terms of explaining all the observed concentrations, and additional verification and study (e.g., validation using a large observed data set, integration with a more accurate runoff model) would be desirable. In comparing LSRMFM and GMFM, discrepancies between the LSRMFM and GMFM outputs were found, as the result of geographical effects, even though the environmental parameters were identical. The geographical variation for LSRMFM output indicated the existence of considerable local human and ecological risks, whereas the GMFM output indicated less average risk. These results demonstrate that the model has the potential for improving the management of pollutant levels under these refined spatial conditions.     

Congener-specific accumulation and environmental risk assessment of polybrominated diphenyl ethers in diverse Korean sewage sludge types

Industrial, domestic wastewater, and livestock sludge samples were collected from 23 wastewater treatment plants in Korea and analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of Σ₁₉PBDE ranged from 4.01 to 10,400 ng/g dry weight. The average Σ₁₉PBDE concentrations in industrial, domestic wastewater, and livestock sludge were 1,560?±?3,610, 402?±?148, and 27.6?±?50.4 ng/g dry weight, respectively. The composition of PBDEs differed according to the type of sludge. Among the PBDE congeners, BDE 209 was dominant in all sludge samples. After BDE 209, relatively high levels were found for BDE 28 and 47 from industrial sludge, BDE 47 and 99 from domestic wastewater sludge, and BDE 206, 207, and 208 from livestock sludge. Using hierarchical cluster analysis, sludges were divided into three groups according to PBDE congener composition. A risk assessment of PBDEs in sludge used for soil amendment was carried out. Preliminary results indicated that the potential risk of soil exposed to PBDEs in sludge was relatively low.     

Characterization of the monthly variation in (1 → 3)-β-d-glucan concentrations in university laboratories

We characterize the monthly variation in (1 → 3)-β-d-glucan concentration measured over the course of 1 year, and we evaluate the characteristics of size selection using a two-stage cyclone sampler. The (1 → 3)-β-d-glucan concentrations were measured in four bio-related laboratories. A total of 156 samples were collected using a new two-stage cyclone sampler. Analysis of (1 → 3)-β-d-glucan was performed using the kinetic Limulus amebocyte lysate assay. The study showed that airborne (1 → 3)-β-d-glucan concentrations were significantly higher in laboratory D (mean ± SD 1,105?±?1,893 pg/m³) and in the spring (5,458 pg/m³). The highest concentration of (1 → 3)-β-d-glucan occurred in the spring, particularly in May.     

Induction of cytochrome P4501A and endocrine disrupting effects of school incinerator residues

The emission of the dioxin-like compounds from on-site waste incinerators of seven schools in Kyonggi Province of Korea was evaluated by determination of the cytochrome P4501A(CYP1A) catalytic activity and antiestrogenic activity using cell culturemicrobioassay. The residue samples were extracted in a Soxhlet apparatus using toluene for 20 hr. The concentrated crude extractswere fractionated with a basic alumina column. Dioxin-like compounds were then extracted. Induction of CYP1A activity in a rat(H4IIE) hepatoma cell line was used as indicator of biologicaleffect of incinerator residues and measured as 7-ethoxyresorufin-O-deethylase(EROD) activities. The EROD activities of fraction II extracts (one of the two extracts) in the H4IIE cells were from 0.044±0.002 to 4.424±0.351 ng-TEQ g^-1 (TCDD Toxicity equivalent), showing relatively high inducing capacity. Antisetrogenicity of the extracts was measured as decrease in E₂-induced cell proliferation. Most of the extracts showed antiestrogenic activity in MCF7-BUS cell.The TEQ levels of the incinerator residues and the antiestrogenicactivities were in good correlation, strongly suggesting that thepotent toxic emissions were indeed produced from the on-site school waste semi-incinerators and could cause the antiestrogenicity.     

Examination of in vivo mutagenicity of sodium arsenite and dimethylarsinic acid in gpt delta rats

Arsenic is a well-known human bladder and liver carcinogen, but its exact mechanism of carcinogenicity is not fully understood. Dimethylarsinic acid(DMAV) is a major urinary metabolite of sodium arsenite(i As~Ⅲ) and induces urinary bladder cancers in rats. DMAVand i As~Ⅲare negative in in vitro mutagenicity tests. However, their in vivo mutagenicities have not been determined. The purpose of present study is to evaluate the in vivo mutagenicities of DMAVand i As~Ⅲin rat urinary bladder epithelium and liver using gpt delta F344 rats.Ten-week old male gpt delta F344 rats were randomized into 3 groups and administered 0,92 mg/L DMAV, or 87 mg/L i As~Ⅲ(each 50 mg/L As) for 13 weeks in the drinking water. In the mutation assay, point mutations are detected in the gpt gene by 6-thioguanine selection(gpt assay) and deletion mutations are identified in the red/gam genes by Spi-selection(Spi-assay). Results of the gpt and Spi-assays showed that DMAVand i As~Ⅲhad no effects on the mutant frequencies or mutation spectrum in urinary bladder epithelium or liver. These findings indicate that DMAVand i As~Ⅲare not mutagenic in urinary bladder epithelium or liver in rats.     

Exposure to heavy metals in blood and risk perception of the population living in the vicinity of municipal waste incinerators in Korea

Background, aim, and scope

The purpose of this study was to monitor and present the heavy metal concentrations in the blood of residents of areas near municipal waste incinerators (MWIs), who are more prone to environmental pollution. We also sought to compare and analyze the residents?? perception of environmental pollution as one of the factors affecting heavy metal concentrations in the blood using a survey about the perceived damage caused by the facilities. Since heavy metal levels in the blood can be affected not only by local environmental pollution but also by personal and occupational factors, heavy metal levels in the blood need to be verified and consistently monitored.

Methods

Residents who live within 300?m of MWIs in Seoul are acknowledged to be under indirect influence according to the Waste Disposal Act. A survey was given to 841 residents living within 300?m of a MWI from 2006 to 2009. The concentrations of heavy metals (lead, cadmium, and mercury) in the blood were measured in the 841 surveyed residents and in 105 residents in reference areas. Additionally, the perception of the damage caused by municipal waste incinerators was investigated using scores from 1 to 5 on a Likert scale.

Results

The measurements of the heavy metal concentrations in the blood showed that the mean concentrations of lead, cadmium, and mercury were 43.1, 1.7, and 1.3?ug/L, respectively. The blood levels of lead and cadmium were slightly higher in the group of the subjects who had resided the longest near the municipal waste incinerators. When compared with the domestic investigation by the Ministry of Environment, the concentrations of lead and cadmium were a little higher, while that of mercury was a little lower. Overall, there was no significant difference in the distribution of heavy metal levels in the blood among age groups. Additionally, the investigation of the perceived damage from municipal waste incinerators showed that the subjects     

Ambient air monitoring of PCDD/Fs and co-PCBs in Gyeonggi-do, Korea

We started the monitoring for PCDD/Fs in ambient air and soil in August 2001, and co-PCBs in January 2002. Decreasing of PCDD/Fs and co-PCBs levels in ambient air were observed. The higher PCDD/Fs levels were found in winter and lower in autumn. We found that the industrial incinerators influenced the PCDD/Fs levels in ambient air. In the 2,3,7,8-substituted PCDD/Fs concentration profiles, the three major congeners occupied 67% of the total mass. In case of co-PCBs, PCB#118, #105 and #77 were observed as the main congeners. Five cluster groups discriminated by ratio of four components, O(8)CDD, 1,2,3,4,6,7,8-H(7)CDD, 1,2,3,4,6,7,8-H(7)CDF and O(8)CDF, were obtained from HCA (hierarchical cluster analysis).