Yodo River Water Research Articles

Occurrence and Treatability of Pesticides Listed as Items for Further Study in Drinking Water in Yodo River Water Resource

Occurrence and Treatability of Pesticides Listed as Items for Further Study in Drinking Water in Yodo River Water Resource

The age of Yodo River water in the Seto Inland Sea

Abstract The age of Yodo River water, the largest river flowing in the Seto Inland Sea (SIS), was calculated using the constituent-oriented age and residence time theory (CART) in order to understand the long-term material transport and environmental issues in this semi-enclosed sea. The Yodo River water was found to have a mean age of 152 days for the entire SIS. Inside the SIS, the age of Yodo River water shows spatial variation ranging from 97 days in Osaka Bay, 199 days in the Harima-Nada, and 450 days in other areas. The age of Yodo River water shows an apparent seasonal variation in the SIS. Tracing water from the Yodo River reveals two pathways for its movement around Osaka Bay: one brings ~5/8 river water directly into the Kii Channel through the Kitan Strait; the other brings ~3/8 river water into the Harima-Nada through the Akashi Strait that eventually enters the Kii Channel through the Naruto Strait. The mean age of Yodo River water is 128 days at the Kitan Strait, 125 days at the Akashi Strait, 203 days at the Naruto Strait, and 271 days at the Bisan Strait. The above estimation considers the return of old Yodo River water into Osaka Bay that does not change the spatial distribution of Yodo River water age inside Osaka Bay but increases the value of water age by ~80%. Without tidal forcing, the mean ages of Yodo River water in Osaka Bay and the Harima-Nada increase by 6% and 51%, respectively, and nearly all the Yodo River water flows directly into the Kii Channel through the Kitan Strait. Without considering baroclinic forcing, the mean ages of Yodo River water in Osaka Bay and the Harima-Nada increases by 52% and 51%, respectively, while the influence of local winds and the Yodo River discharge on the age of Yodo River water are negligible.

The life cycle and molecular phylogeny of a gorgoderid trematode recorded from the mussel Nodularia douglasiae in the Yodo River, Japan

In 2009, a novel larval trematode of the family Gorgoderidae was found in the gonads of Nodularia douglasiae (Unionidae) from the lower reaches of the Yodo River, Osaka Prefecture, Japan. This is the first collection of trematodes in a unionid mussel in Japan. We investigated the morphology and life cycle of the trematode, and conducted a molecular phylogenetic analysis with other gorgoderid species, both those collected in the Yodo River water system and those reported in the literature.Immature adult worms were obtained from the ureters of the common carp Cyprinus carpio, the first known instance of a gorgoderid from these fish in Japan. Morphological characteristics and molecular data show that it belongs to the subfamily Gorgoderinae (genus Phyllodistomum sensu lato). Regarding the morphology, first intermediate host, and the infection site of adult worms, it resembles Phyllodistomum elongatum Nybelin, 1926 from Europe, but no comparable molecular data exist for Ph. elongatum. Three cytochrome c oxidase subunit I haplotypes were detected in the specimens analyzed, suggesting that the present species is indigenous to the Yodo River water system. The 28S ribosomal DNA data showed that this species is a member of the clade consisting of Ph. cf. symmetorchis, Ph. folium, Pseudophyllodistomum and Xystretrum. However, its phylogenetic position within the clade differs between the maximum likelihood and maximum parsimony trees, and the sister species of the present species remain unclear.

Formation of N-nitrosodimethylamine (NDMA) by ozonation of dyes and related compounds

Formation of N-nitrosodimethylamine (NDMA) by ozonation of commercially available dyes and related compounds was investigated. Ozonation was conducted using a semi-batch type reactor, and ozone concentration in gas phase and the ozone gas flow were 10 mg L −1 and 1.0 L min −1, respectively. NDMA was formed by 15 min of ozonation of seven out of eight selected target compounds (0.05 mM) at pH 7. All the target compounds with N, N-dimethylamino functions were NDMA precursors in ozonation. The lowest and highest NDMA concentrations after ozonation of the target compounds were 13 ng L −1 for N, N-dimethylformamide (DMF) and 1600 ng L −1 for N, N-dimethyl- p-phenylenediamine (DMPD), respectively. NDMA concentrations after 15 min of ozonation of 0.05 mM methylene blue (MB) and DMPD increased with an increase in pH in its range of 6–8. The effects of coexisting compounds on NDMA concentrations after 15 min of ozonation of 0.05 mM MB and DMPD were examined at pH 7. NDMA concentrations after ozonation of MB and DMPD increased by the presence of 0.05 mM (0.7 mg L −1 as N) nitrite ( NO 2 - ) ; 5000 ng L −1 for MB and 4000 ng L −1 for DMPD. NDMA concentration after MB ozonation decreased by the presence of 5 mM tertiary butyl alcohol (TBA), a hydroxyl radical (HO·) scavenger, but that after DMPD ozonation was increased by the presence of TBA. NDMA concentrations after ozonation of MB and DMPD were not affected by the presence of 0.16 mM (5.3 mg L −1) hydrogen peroxide (H 2O 2). When 0.05 mM MB and DMPD were added to the Yodo and Tone river water samples, NDMA concentrations after 15 min of their ozonation at pH 7 increased compared with those in the case of addition to ultrapure water samples.

Evaluation of assimilable organic carbon in the Yodo River and the effect of coagulation on its control

Biodegradable organic compounds in Yodo River water, the coagulated water and those ozonated waters were characterized on the concentration of assimilable organic carbon (AOC), the apparent molecular size and the sensitivity to E260 (UV absorbance at the wavelength of 260 nm). High molecular (>5,000 Da) organic compounds which were insensitive to E260 were contained with relatively high concentration in Yodo River, whereas they were not detectable as AOC. The AOC concentration in Yodo River was reduced by coagulation because the phosphorus concentration sharply decreased. The AOC concentration rapidly increased with the reduction of E260 and slowly with the depolymerization of high molecular organic compounds during the ozonation. However, 40-50% of AOC increasing with the ozonation was reduced by the coagulation. Furthermore, batch incubations of native bacteria living in the Yodo River were conducted in order to examine the validity of the apparent AOC concentration as an indicator of the regrowth potential. The AOC concentration calculated as acetate carbon equivalent would not exactly represent the concentration of the available carbon for the assimilation. However, maximum cell numbers for the incubation period were generally proportional to apparent AOC concentrations even if phosphorus limitation. In conclusion, it is suggested that coagulation is an effective process in controlling the concentration of AOC and is a useful indicator to evaluate the regrowth potential of heterotrophic bacteria in Yodo River.

淀川表流水中に含有する生物同化可能有機炭素および細菌増殖ポテンシャルの浄水処理に伴う基礎的挙動

Biodegradable organic substances in Yodo River water, its coagulated water and the ozonated water were analyzed in terms of the concentration of assimilatable organic carbon (AOC), the apparent molecular weight and the E260 absorbability. The fundamental behaviors of AOC through coagulation and ozonation were investigated. Yodo River water contained a relatively high content of macro organic compounds (>5,000 Da) that did not exhibit E260 absorbing features. However, these compounds were not detected as AOC. Coagulation resulted in decreases in the concentration of AOC by up to 75%, due to reductions in the phosphorus concentration. During ozonation, the AOC concentration increased rapidly with the reduction of E260 and increased slowly following the change of some large molecular organic compounds to small ones. However, 30-50 % of AOC that could be increased through ozonation was reduced by pre-coagulation.In addition, water samples prepared under the condition of different limiting substrates were subjected to AOC measurements and batch incubation tests for bacteria living in Yodo River. Experimental results indicated that the AOC concentration converted to acetate equivalent could not represent the concentration of the available carbon for assimilation. However, its apparent value was probably reflective of the growth potential of bacteria even under the phosphorus limitation. Thus, it was suggested that the apparent AOC concentration is a useful indicator for evaluating the regrowth potential of native bacteria in Yodo River.

P XIII.44 - P XIII.44 Mutagenicity of organic pollutants in the Yodo River water with an O-acetyltransferase-overexpressing strain

P XIII.44 - P XIII.44 Mutagenicity of organic pollutants in the Yodo River water with an O-acetyltransferase-overexpressing strain

Quantification of mutagenic/carcinogenic heterocyclic amines, MeIQx, Trp-P-1, Trp-P-2 and PhIP, contributing highly to genotoxicity of river water

Four mutagenic/carcinogenic heterocyclic amines (HCAs), 2-amino-3,8-dimethylimidazo[4,5- f]quinoxaline (MeIQx), 3-amino-1,4-dimethyl-5 H-pyrido[4,3- b]indole (Trp-P-1), 3-amino-1-methyl-5 H-pyrido[4,3- b]indole(Trp-P-2) and 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP), in organic extracts obtained by blue rayon hanging method from the Yodo River water were quantified. Blue rayon extracts obtained were separated in two stages of fractionation by reversed-phase high performance liquid chromatography (HPLC), and the quantification of corresponding fractions was performed by HPLC with an electrochemical detector for MeIQx and a fluorometric detector for Trp-P-1, Trp-P-2 and PhIP. The geometrical mean values of MeIQx, Trp-P-1, Trp-P-2 and PhIP in extracts collected at 11 locations from the Yodo River systems were 4.8, 26.9, 37.3, and 11.9 ng/g blue rayon equivalent, respectively. The total amounts of four HCAs accounted for mean 24% of the genotoxicity of blue rayon extracts evaluated by the umu test using an O-acetyltransferase-overproducing strain NM2009.

Sources of mutagenic substances present in the Yodo River water

Sources of mutagenic substances present in the Yodo River water

Mitotic toxicity, sister chromatid exchange, and rec assay of pesticides.

Genotoxicity of 10 pesticides (chlornitrofen, chlomethoxyfen, molinate, thiobencarb, simazine, simetryn, diazinon, iprofenfos, piperofos and oxadiazone) was studied by mitotic toxicity, sister chromatid exchange, and rec assay. The pesticides are detected frequently at high levels in the Yodo River water in Osaka, Japan, which is used for drinking water by thirteen million people. Mitotic toxicity was evaluated by mitotic index (MI) and second mitosis index (SI), using a Chinese hamster cell line V79. SI is the rate of twice divided metaphases in chromosome preparation for sister chromatid exchange. All the pesticides decreased the two indices dose-dependently. MI50 and SI50, the concentrations of pesticides which lowered the indices to 50% of the solvent control, was determined. The MI50 and SI50 of each pesticide were very similar, and the pesticides did not hinder cell division specifically. None of the pesticides induced more sister chromatid exchanges than 1.5 times the solvent control. Chlomethoxyfen and simazine induced sister chromatid exchanges significantly in V79 cells, but the dose dependencies were poor. Simetryn had rec effect and was concluded to have DNA damaging activity.

Evaluation of Mutagenicity of Municipal River Water Concentrated Using XAD Resin Column Method

The physico-chemical and mutagenic properties of organic concentrates from the Yodo river water were investigated using XAD resin column method with XAD-2, XAD-4 and XAD-8 under various adsorptive and desorptive conditions. XAD resin concentrates showed to be directly and indirectly frameshift mutagenic. Organic mutagens in the Yodo river water were almost absorbed to XAD-2 resin and then desorbed effectively with CH2Cl2. The physico-chemical properties of these concentrates were acidic and hydrophobic. Additionally organic mutagens which possess basic and hydrophilic properties may contribute to the mutagenicity.

ANTI-Ro IN SJÖGREN’S SYNDROME AND SYSTEMIC LUPUS ERYTHEMATOSUS

Anti-Ro autoantibodies are frequently found in the sera of patients with Sjögren's syndrome, systemic lupus erythematosus, and subacute cutaneous lupus erythematosus as well as in the sera of mothers of infants with the neonatal lupus syndrome. Close associations have been found between anti-Ro and a number of clinical manifestations, particularly including hematologic cytopenias, heart block, and photosensitive skin rashes. Serologic and genetic associations have been found between anti-Ro and anti-La, rheumatoid factor, hypergammaglobulinemia, the histocompatibility alleles DQ1 and DQ2, and alleles of the T-cell receptor beta chain gene. The origin of anti-Ro and other autoantigens is thought to relate to the etiology of Sjögren's syndrome and systemic lupus erythematosus and remains the most fundamental unanswered question preventing a comprehensive understanding of these diseases.

Comparative Studies on Preconcentration Methods for Detecting the Organic Mutagens in Water.

Several preconcentration methods for the detection of organic mutagens in water, including blue rayon and XAD-2 resin column methods, were compared. The mutagenicity test of the extracts from blue rayons hung at the six points of the Yodo river revealed similar frame-shift type mutagenicity to our previous report with the XAD-2 resin column method. For the quantitative concentration of polycyclic aromatic hydrocarbons in water, it was shown that the blue rayon column method was more efficient than the blue rayon hanging method or XAD-2 resin column method. Extracts from the Yodo river water and sewage treatment plant effluent obtained by the XAD-2 resin column and blue rayon hanging methods may contain nitroarenes and aminoarenes.

Sea and fresh water conservation

Sea water qualities are closely related to river water qualities. Therefore, the most important thing is to prevent fresh water pollution from a view point of sea water conservation. The Yodo River is the biggest river in the Kinki district which flows into the Osaka bay and the major water source for water industries serving 10 million people. Recently, the water has been polluted due to the rapid economic growth etc.. We wish to control the Yodo River water pollution, in cooperation with the organization concerened to sea water.

Water Quality Management in the Yodo River Basin – Case Study

This study investigated an appropriate sewage treatment system to be applied in a river basin where river water is re-used repeatedly. Many sewage effluents are discharged into the river's up-streamside from intake points for drinking water. The Yodo river was selected as a case study. The obtained results are as follows; 1) Investigations of COD, NH4-N, THMFP are necessary in polluted rivers used as drinkingwater sources. 2) The effect of a sewage treatment system construction for river water conservation should be evaluated with the predicted water quality in the low flow and the average flow condition. 3) Time and place variations of NH4-N concentration in the Yodo river are predicted by adaptation of a two dimensional unsteady diffusion model. 4) The greater part of TN or NH4-N load deposited at the Yodo river branches in the dry weather condition are washed away by the wet flow condition. 5) It will be possible to maintain the present water quality level for TN and NH4-N in the future, despite an increase of population in the Yodo area and the construction of a conventional sewage treatment system. 6) However, an adaptation of an advanced sewage treatment system is recommended for re-use as drinking water of the Yodo river water.

化学物質の環境中での挙動 淀川水系における長期実態調査を例として

化学物質の環境中での挙動 淀川水系における長期実態調査を例として