Using NOAA AVHRR data to assess flood damage in China

The article used two NOAA-14 Advanced Very High ResolutionRadiometer (AVHRR) datasets to assess flood damage in the middleand lower reaches of China's Changjiang River (Yangtze River) in 1998. As the AVHRR is an optical sensor, it cannot penetratethe clouds that frequently cover the land during the flood season, and this technology is greatly limited in flood monitoring. However the widely used normalized difference vegetation index (NDVI) can be used to monitor flooding, sincewater has a much lower NDVI value than other surface features.Though many factors other than flooding (e.g. atmospheric conditions, different sun-target-satellite angles, and cloud) can change NDVI values, inundated areas can be distinguished fromother types of ground cover by changes in the NDVI value beforeand after the flood after eliminating the effects of other factors on NDVI. AVHRR data from 26 May and 22 August, 1998 wereselected to represent the ground conditions before and after flooding. After accurate geometric correction by collecting GCPs,and atmospheric and angular corrections by using the 6S code, NDVI values for both days and their differences were calculatedfor cloud-free pixels. The difference in the NDVI values betweenthese two times, together with the NDVI values and a land-use map, were used to identify inundated areas and to assess the arealost to the flood. The results show a total of 358 867 ha, with 207 556 ha of cultivated fields (paddy and non-irrigated field) inundated during the flood of 1998 in the middle and lower reaches of the Changjiang River Catchment; comparing with the reported total of 321 000 and 197 000 ha, respectively. The discrimination accuracy of this method was tested by comparing the results from two nearly simultaneous sets of remote-sensingdata (NOAA's AVHRR data from 10 September, 1998, and JERS-1 synthetic aperture radar (SAR) data from 11 September, 1998, with a lag of about 18.5 hr) over a representative flooded regionin the study area. The results showed that 67.26% of the total area identified as inundated using the NOAA data was also identified as inundated using the SAR data.     

Nervous system disruption and concomitant behavioral abnormality in early hatched pufferfish larvae exposed to heavy oil

BACKGROUND AND OBJECTIVE: Spills of heavy oil (HO) over the oceans have been proven to have an adverse effect on marine life. It has been hypothesized that exposure of early larvae of sinking eggs to HO leads largely to normal morphology, whereas abnormal organization of the developing neural scaffold is likely to be found. HO-induced disruption of the nervous system, which controls animal behavior, may in turn cause abnormalities in the swimming behavior of hatched larvae. To clarify the toxicological effects of HO, we performed exposure experiments and morphological and behavioral analyses in pufferfish (Takifugu rubripes) larvae. EXPERIMENTAL PROCEDURE: Fertilized eggs of pufferfish were exposed to 50?mg/L of HO for 8?days and transferred to fresh seawater before hatching. The hatched larvae were observed for their swimming behavior, morphological appearance, and construction of muscles and nervous system. RESULTS AND DISCUSSION: In HO-exposed larvae, we did not detect any anomaly of body morphology. However, they showed an abnormal swimming pattern and disorganized midbrain, a higher center controlling movement. Our results suggest that HO-exposed fishes suffer developmental disorder of the brain that triggers an abnormal swimming behavior and that HO may be selectively toxic to the brain and cause physical disability throughout the life span of these fishes.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho coplanar polychlorinated biphenyls (non-ortho PCBs), and mono-ortho coplanar polychlorinated biphenyls (mono-ortho PCBs) in blood collected between 2002 and 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years) and 94 were multipara (mean: 32.4 years). The arithmetic mean total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs of primiparous and multiparous mothers in Sapporo City were 17.4 (median: 15.7) and 14.0 (median: 13.9)pgTEQ/glipid, respectively, and the concentrations were in the range of 6.6-43.4 and 3.4-28.2pgTEQ/glipid, respectively. In regard to the relationship between the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in maternal blood and the number of deliveries or age of primiparous and multiparius mothers, the levels of these dioxin-like compounds tended to decrease with increases in the number of deliveries and significantly increased with increasing maternal age in both groups. Furthermore, significant correlations were observed between the total TEQ concentrations of these dioxin-like compounds and the age of primiparae and multiparae. The total TEQ concentration of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs measured in 195 pregnant women has decreased compared to past levels in Japan for the last several decades. The results of the present study have indicated that dioxin contamination in the blood of young women in Japan is continuing to decrease.     

Phytoextraction of cadmium by rice (Oryza sativa L.), soybean (Glycine max (L.) Merr.), and maize (Zea mays L.)

Selecting a phytoextraction plant with high Cd-accumulating ability based on the plant's compatibility with mechanized cultivation techniques may yield more immediately practical results than selection based on high tolerance to Cd. Rice (Oryza sativa L., cv. Nipponbare and Milyang 23), soybean (Glycine max [L.] Merr., cv. Enrei and Suzuyutaka), and maize (Zea mays L., cv. Gold Dent) were grown on one Andosol and two Fluvisols with low concentration of Cd contamination ranging from 0.83 to 4.29 mg Cd kg(-1), during 60 days in pots (550 mL) placed in a greenhouse. Shoot Cd uptake was as follows: Gold Dent相似文献   

Thermodynamic and kinetic studies on Cs+- and Sr2+-exchange in natural zeolite from Akita,Japan

Thermodynamic and kinetic studies on the adsorption of Cs⁺ and Sr²⁺ by Na-exchanged clinoptilolite-rich zeolite rock from Akita (Northern Japan) were performed for the purpose of nuclear waste treatment. The thermodynamic parameters such as selectivity coefficient, thermodynamic equilibrium constant, and standard free energy of exchange were evaluated. These values indicated that the selectivity order was determined as Cs⁺ > Na⁺ > Sr²⁺. In order to discuss the adsorption mechanism of Cs⁺ and Sr²⁺ onto Na-exchanged clinoptilolite, the effective diffusion coefficients were calculated and two kinetic models, pseudo-first-order and pseudo-second-order kinetic model, were tested. For all systems studied, chemisorption seems significant in the rate-controlling step, and the pseudo-second-order kinetic model provided the best correlation of the experimental data.     

Estimation of contribution from non-point sources to perfluorinated surfactants in a river by using boron as a wastewater tracer

The contribution of non-point sources to perfluorinated surfactants (PFSs) in a river was evaluated by estimating their fluxes and by using boron (B) as a tracer. The utility of PFSs/B as an indicator for evaluating the impact of non-point sources was demonstrated. River water samples were collected from the Iruma River, upstream of the intake of drinking water treatment plants in Tokyo, during dry weather and wet weather, and 13 PFSs, dissolved organic carbon (DOC), total nitrogen (TN), and B were analyzed. Perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUA), and perfluorododecanoate (PFDoDA) were detected on all sampling dates. The concentrations and fluxes of perfluorocarboxylates (PFCAs, e.g. PFOA and PFNA) were higher during wet weather, but those of perfluoroalkyl sulfonates (PFASs, e.g. PFHxS and PFOS) were not. The wet/dry ratios of PFSs/B (ratios of PFSs/B during wet weather to those during dry weather) agreed well with those of PFS fluxes (ratios of PFS fluxes during wet weather to those during dry weather), indicating that PFSs/B is useful for evaluating the contribution from non-point sources to PFSs in rivers. The wet/dry ratios of PFOA and PFNA were higher than those of other PFSs, DOC, and TN, showing that non-point sources contributed greatly to PFOA and PFNA in the water. This is the first study to use B as a wastewater tracer to estimate the contribution of non-point sources to PFSs in a river.     

Biodegradation of endosulfan by Mortieralla sp. strain W8 in soil: Influence of different substrates on biodegradation

To examine the bioremediation potential of Mortierella sp. strain W8 in endosulfan contaminated soil, the fungus was inoculated into sterilized and unsterilized soil spiked with endosulfan. Wheat bran and cane molasses were used as substrates to understand the influence of different organic materials on the degradation of endosulfan in soil. Strain W8 degraded α- and β-endosulfan in both sterilized and unsterilized soil. In unsterilized soil with wheat bran+W8, α- and β- endosulfan were degraded by approximately 80% and 50%, respectively after 28 d incubation against the initial endosulfan concentration (3 mg kg(-1) dw). The corresponding values for α- and β-endosulfan degradation with wheat bran only were 50% and 3%. Endosulfan diol metabolite was detected after 14 d incubation in wheat bran+W8 whereas it was not found with wheat bran only. Production of endosulfan sulfate, the main metabolite of endosulfan, was suppressed with wheat bran+W8 treatment compared with wheat bran only. It was demonstrated that wheat bran is a more suitable substrate for strain W8 than cane molasses. Wheat bran+W8 is a superior fungus and substrate mix for bioremediation in soil contaminated with endosulfan.     

Perfluorinated surfactants (PFSs) in size-fractionated street dust in Tokyo

We investigated perfluorinated surfactants (PFSs) in size-fractionated street dust to identify their occurrence, contributions from traffic, and potential routes of entry into waters. Street dust was collected from residential areas and heavily trafficked areas in Tokyo and sorted into fine (<63 microm) and coarse fractions (63-2000 microm). Five PFS species were analyzed by liquid chromatography-tandem mass spectrometry: perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUA). In fine fractions, PFS contents were significantly higher in heavily trafficked street dust than in residential street dust, but in coarse fractions, no significant differences were observed. Additionally, in heavily trafficked areas, PFS contents were significantly higher in fine fractions than in coarse fractions, but in residential areas, no significant differences were observed. PFS compositions differed between size fractions, not locations, indicating differences in sources between size fractions. Fine particles from traffic contributed to PFSs in street dust. Street dust possibly acts as the origin of PFSs in street runoff and eventually enters waters. This is the first report of PFSs in street dust.     

Synergistic increase in cell lethality by dieldrin and H2O2 in rat thymocytes: Effect of dieldrin on the cells exposed to oxidative stress

Dieldrin, one of persistent pesticides, is highly resistant to biotic and abiotic degradation. It is accumulated in organisms. Recent studies suggest that dieldrin exerts a potent cytotoxic action on cells exposed to oxidative stress. In this study, the effect of dieldrin on rat thymocytes exposed to hydrogen peroxide (H₂O₂)-induced oxidative stress was examined. Dieldrin at 5 μM and H₂O₂ at 300 μM slightly increased cell lethality from a control value of 5.4 ± 0.5% (mean ± standard deviation of four experiments) to 7.8 ± 1.3% and 9.0 ± 0.3%, respectively. Simultaneous application of dieldrin and H₂O₂ significantly increased cell lethality to 46.2 ± 1.8%. The synergistic increase in cell lethality was dependent on dieldrin concentration (0.3–5 μM) but not on H₂O₂ concentration (30–300 μM). Dieldrin accelerated H₂O₂-induced cell death, which was estimated with the help of annexin V-FITC and propidium iodide. Presence of either dieldrin or H₂O₂ decreased the cellular content of nonprotein thiol and increased intracellular Zn²⁺ concentration. The combination of dieldrin and H₂O₂ further pronounced these effects. TPEN, a chelator of intracellular Zn²⁺, significantly attenuated the synergistic increase in cell lethality induced by dieldrin and H₂O₂. It is, therefore, suggested that dieldrin augments the cytotoxicity of H₂O₂ in a Zn²⁺-dependent manner.