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51.
In vitro fertilization (IVF) is one of the most important treatments of infertility to provide a chance of conceiving. In IVF treatment, sperm are washed and motile sperm are isolated with sperm washing media (SWM) for the purpose of fertilization; fertilized ova are then incubated for a maximum of 5 or 6 d in media for IVF (IVFM). The exposure of fertilized ova to chemicals via such media has not been studied. We determined the concentrations of two contaminants; di(2-ethylhexyl)phthalate (DEHP) and its hydrolyzed product mono(2-ethylhexyl)phthalate (MEHP) in IVFM, SWM, and protein sources (PS: human serum albumin or serum substitute) for IVFM and SWM. The DEHP and MEHP in these media were extracted by a liquid-liquid extraction method and their concentrations determined by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Fifteen IVFM, nine SWM, and six PS obtained in Japan were examined. The concentrations of DEHP and MEHP in IVFM and SWM were <10-114 and <2.0-263 ng mL−1, respectively. The concentrations of both DEHP and MEHP were higher in the media containing PS than in those without PS. Either MEHP alone or both DEHP and MEHP were detected in PS. The concentrations of DEHP and MEHP in PS were <10-982 and 47.0-1840 ng mL−1, respectively. The DEHP and MEHP detected in these media were derived from PS. This is the first study on the chemical contamination of IVFM, SWM, and PS. 相似文献
52.
N-Nitrosodimethylamine (NDMA) is a potent carcinogen that yields a cancer risk of 10−6 at concentrations as low as 0.7 ng L−1. Tentative guideline values are set at 3 ng L−1 in California, USA; 9 ng L−1 in Ontario, Canada; 40 ng L−1 nationwide in Canada; and 100 ng L−1 by the World Health Organization. NDMA is a great concern in treating reclaimed water as well as drinking water. UV degradation can be considered effective degradation method. A 1-log reduction of NDMA is achieved by 1000 mJ cm−2 of a 254-nm low pressure (LP) mercury UV lamp. However, a higher degradation efficiency than that provided by LP lamps is desired in practical treatment. In this study, the effects of wavelength and water quality were investigated to achieve higher degradation efficiency. The effects of wavelength were examined by comparing three UV lamps: a 222-nm Kr Cl Excimer UV lamp, a 254-nm LP mercury UV lamp, and a 230- to 270-nm filtered medium pressure (FMP) mercury UV lamp. The 222-nm lamp and FMP lamp achieved 4 times and 2.8 times higher degradation efficiency, respectively, than the conventional 254-nm LP lamp. Effects on water quality were also simulated by using absorption spectrum data of nitrate solutions and process water from a drinking-water treatment plant. In the simulation, the 222-nm lamp was affected by UV-absorbing compounds in the water, whereas the FMP lamp showed more stable degradation efficiency. Appropriate use of these three types of lamps could enhance the efficiency of degradation of NDMA. 相似文献
53.
We estimated the cost of flood damage using numerical simulations based on digital map data and the flood control economy
investigation manual submitted by the Ministry of Land, Infrastructure, Transportation, and Tourism in Japan. The simulation
was carried out using a flood model incorporating representative precipitation data for all of Japan. The economic predictions,
which estimate flood damage caused by extreme rainfall for the return periods of 5, 10, 30 50, and 100 years, are as follows:
(1) the cost of flood damage increases nearly linearly with increases in extreme precipitation; (2) assuming that flood protection
is completed for a 50-year return period of extreme rainfall, the benefit of flood protection for a 100-year return period
of rainfall is estimated to be 210 billion USD; (3) the average annual expected damage cost for flooding is predicted to be
approximately 10 billion USD per year, based on the probability of precipitation for a return period of 100 years and assuming
that flood control infrastructures will be completed within the 50-year return period and will be able to protect from flooding
with a 50-year return period; (4) urban and rural areas are predicted to suffer high and low costs of damage, respectively.
These findings will help to derive measures to enhance flood protection resulting from climate change. 相似文献
54.
Surface ozonation of polyvinyl chloride for its separation from waste plastic mixture by froth floatation 总被引:1,自引:1,他引:0
Mallampati Srinivasa Reddy Tetsuji Okuda Keisuke Kurose Tsung-Yueh Tsai Satoshi Nakai Wataru Nishijima Mitsumasa Okada 《Journal of Material Cycles and Waste Management》2010,12(4):326-331
Selective surface modification of polyvinyl chloride (PVC) by ozonation was evaluated to facilitate the separation of PVC
from other heavy plastics with almost the same density as PVC, especially polyethylene terephthalate (PET), by the froth flotation
process. The optimum froth flotation conditions were investigated, and it was found that at 40°C, 90% of PVC and PET plastics
floated. The bubble size became larger and the area covered with bubbles on the plastic surface was reduced with increasing
temperature. Optimum PVC separation was achieved with the flotation solution at 40°C and mixing at 180–200 rpm, even for sheet
samples 10 mm in size. Combined treatment by ozonation and froth flotation is a simple, effective, and inexpensive method
for PVC separation from waste plastics. 相似文献
55.
Tropical deforestation is occurring at an alarming rate, threatening the ecological integrity of protected areas. This makes it vital to regularly assess protected areas to confirm the efficacy of measures that protect that area from clearing. Satellite remote sensing offers a systematic and objective means for detecting and monitoring deforestation. This paper examines a spectral change approach to detect deforestation using pattern decomposition (PD) coefficients from multitemporal Landsat data. Our results show that the PD coefficients for soil and vegetation can be used to detect deforestation using change vector analysis (CVA). CVA analysis demonstrates that deforestation in the Kinabalu area, Sabah, Malaysia has significantly slowed from 1.2% in period 1 (1973 and 1991) to 0.1% in period 2 (1991 and 1996). A comparison of deforestation both inside and outside Kinabalu Park has highlighted the effectiveness of the park in protecting the tropical forest against clearing. However, the park is still facing pressure from the area immediately surrounding the park (the 1km buffer zone) where the deforestation rate has remained unchanged. 相似文献
56.
Polychlorinated dibenzothiophenes (PCDTs) in sediment, soil, and fly ash samples collected in Japan were analyzed and their dioxin-like endocrine-disruption potential and photodegradability investigated. PCDTs were detected in all three types of sample, although the concentrations were lower than those of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). An Ah-immunoassay confirmed that 2,3,7,8-TeCDT, 1,2,3,7,8-PeCDT, 1,2,3,7,8,9-HxCDT, and 1,2,3,4,7,8,9-HpCDT had Ah receptor-binding activities, which means that these PCDTs have the potential to cause dioxin-like endocrine-disruption. Photodegradation of PCDTs by UV irradiation was accompanied by dechlorination. The photodegradation rates of 2,3,7,8-TeCDT and OCDT were lower than the rates for the corresponding PCDF isomers (2,3,7,8-TeCDF and OCDF), which indicates that PCDTs are more stable than PCDFs to photodegradation. 相似文献
57.
Juraj Medo Jana Maková Silvia Kovácsová Kamila Majerčíková Soňa Javoreková 《Journal of environmental science and health. Part. B》2013,48(12):871-883
This investigation was undertaken to determine the impact of the insecticides Dursban 480 EC (with organophosphate compound chlorpyrifos as the active ingredient) and Talstar 10 EC (with pyrethroid bifenthrin as the active ingredient) on the respiration activity and microbial diversity in a sandy loam luvisol soil. The insecticides were applied in two doses: the maximum recommended dose for field application (15 mg kg?1 for Dursban 480 EC and 6 mg kg?1 for Talstar 10 EC) and a 100-fold higher dose for extrapolation of their effect. Bacterial and fungal genetic diversity was analysed in soil samples using PCR DGGE and the functional diversity (catabolic potential) was studied using BIOLOG EcoPlates at 1, 3, 7, 14, 28, 56 and 112 days after insecticide application. Five bacterial groups (α, β, γ proteobacteria, firmibacteria and actinomycetes) and five groups of fungi or fungus-like microorganisms (Ascomycota, Basidiomycota, Chytridiomycota, Oomycota and Zygomycota) were analysed using specific primer sets. This approach provides high resolution of the analysis covering majority of microorganisms in the soil. Only the high-dose Dursban 480 EC significantly changed the community of microorganisms. We observed its negative effect on α- and γ-proteobacteria, as the number of OTUs (operational taxonomic units) decreased until the end of incubation. In the β-proteobacteria group, initial increase of OTUs was followed by strong decrease. Diversity in the firmibacteria, actinomycetes and Zygomycota groups was minimally disturbed by the insecticide application. Dursban 480 EC, however, both positively and negatively affected certain species. Among negatively affected species Sphingomonas, Flavobacterium or Penicillium were detected, but Achromobacter, Luteibacter or Aspergillus were supported by applied insecticide. The analysis of BIOLOG plates using AWCD values indicated a significant increase in metabolic potential of microorganisms in the soil after the high-dose Dursban application. Analysis of respiration demonstrated high microbial activity after insecticide treatments; thus, microbial degradation was relatively fast. The half-life of the active insecticide compounds were estimated within the range of 25 to 27 days for Talstar and 6 to 11 days for Dursban and higher doses stimulated degradation. The recommended dose levels of both insecticides can be considered as safe for microbial community in the soil. 相似文献
58.
Henrieta Patayová Soňa Wimmerová Kinga Lancz Ľubica Palkovičová Beata Drobná Anna Fabišiková Ján Kováč Irva Hertz-Picciotto Todd A. Jusko Tomáš Trnovec 《Environmental science and pollution research international》2013,20(12):8557-8566
The aim of this study was to relate placental transfer, quantified by the cord to maternal serum concentration ratio (C/M), of five organochlorine pesticides (OCP) hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), γ-hexachlorocyclohexane (γ-HCH) , p,p'-DDT, p,p'-DDE and 15 polychlorinated biphenyl (PCB) congeners (28, 52, 101, 105, 114, 118, 123+149, 138+163, 153, 156+171, 157, 167, 170, 180, and 189) to anthropometric, socioeconomic, and maternal health characteristics. We included into the study 1,134 births during the period 2002–2004 from two districts in eastern Slovakia with high organochlorine concentrations relative to other areas of the world. Only concentrations >LOD were taken into account. Variables as age, weight and height of mothers, parity, ethnicity, alcohol consumption, illness during pregnancy, smoking during pregnancy, hypertension, respiratory diseases, rheumatoid arthritis and diabetes mellitus, and birth weight were related to C/M. Results of regression analyses showed that C/M was predicted by several factors studied. Positive associations were observed for gestational alcohol consumption, fewer illnesses during pregnancy, maternal age, and maternal weight. Caucasians had a greater C/M compared to Romani for wet weight data of congeners 170 and 180 and in contrast C/M for HCB was greater in Romani. Our results show that drinking mothers compared to abstaining expose their fetuses not only to alcohol but to an increased level of several PCB congeners. A straightforward explanation of associations between C/M shifts and factors studied is very difficult, however, with regard to the high lipophilicity of OCPs and PCBs, changes in their kinetics probably reflect lipid kinetics. 相似文献
59.
Mallampati Srinivasa Reddy Takefumi Yamaguchi Tetsuji Okuda Tsung-Yueh Tsai Satoshi Nakai Wataru Nishijima Mitsumasa Okada 《Waste management (New York, N.Y.)》2010,30(4):597-601
This study describes the possible separation of chlorinated plastic films (PVC and PVDC) from other heavy plastic packaging waste (PPW) by selective twist formation and gravity separation. Twists formation was mechanically induced in chlorinated plastic films, whereas twist formation did not occur in PS and PET films. After twist formation, all the films had the apparent density of less than 1.0 g/cm3 and floated in water even though the true density was more than 1.0 g/cm3. However, the apparent density of the PS and the PET films increased with agitation to more than 1.0 g/cm3, whereas that of chlorinated plastic films was kept less than 1.0 g/cm3. The main reason would be the air being held inside the chlorinated plastic films which was difficult to be removed by agitation. Simple gravity separation after twist formation was applied for artificial film with 10 wt.% of the chlorinated films and real PPW films with 9 wt.% of the chlorinated films. About 76 wt.% of the artificial PPW films and 75 wt.% of real PPW films after the removal of PP and PE were recovered as settling fraction with 4.7 wt.% and 3.0 wt.% of chlorinated plastic films, respectively. These results indicate that simple gravity separation process after twist formation can be used to reduce the chlorinated plastic concentration from mixed heavy PPW films. 相似文献
60.
Trnovec T Dedík L Jusko TA Lancz K Palkovičová L Kočan A Šovčíková E Wimmerová S Tihányi J Patayová H Hertz-Picciotto I 《Chemosphere》2011,85(11):1687-1693
Investigators have typically relied on a single or few discrete time points as measures of polychlorinated biphenyl (PCB) body burden, however health effects are more likely to be the result of integrative exposure in time, optionally expressed as an area under the time curve (AUC) of PCB serum concentration. Using data from a subgroup of 93 infants from a birth cohort in eastern Slovakia—a region highly polluted by PCBs—we fit a system type model, customized to our longitudinal measures of serum PCB concentrations in cord, 6, 16, and 45 month blood specimens. The most abundant congener, PCB 153, was chosen for modeling purposes. In addition to currently used methods of exposure assessment, our approach estimates a concentration time profile for each subject, taking into account mean residence time of PCB 153 molecules in the body, duration of breast feeding, hypothetical PCB 153 concentration in steady-state without breast feeding and alternately without normal food intake. Hypothetical PCB 153 concentration in steady-state without normal food intake correlates with AUC (r = 0.84, p < 0.001) as well as with duration of breast feeding (r = 0.64, p < 0.001). It makes possible to determine each subject’s exposure profile expressed as AUC of PCBs serum concentration with a minimum model parameters. PCB body burden in most infants was strongly associated with duration of breast feeding in most, but not all children, was apparent from model output. 相似文献