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Response to W. Kramer: The human sex odds at birth after the atmospheric atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities: comment (doi:10.1007/s11356-011-0644-8)
2012
Scherb, Hagen | Voigt, Kristina
INTRODUCTION: This paper is in response to criticism of our article “The human sex odds at birth after the atmospheric atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities” published in Environ Sci Pollut Res 18(5):697–707, 2011. METHODS: Our findings and methods concerning the disturbed human sex odds at birth have been criticized in this journal for being artifacts of data mining, that the concept of statistical significance was misunderstood, and that confounding factors have not been accounted for. Here, we show that this criticism has no basis. We applied well-established statistical methods to large official data sets, and confounding is less important at the level of secular sex odds trends in aggregated annual figures from countries or continents. RESULTS AND CONCLUSIONS: Moreover, our results are strengthened by recent findings concerning increased infant death sex odds in Germany and increased Down syndrome prevalence at birth across Europe after Chernobyl. Prompted by our studies, an official investigation in Lower Saxony, Germany, by the “Niedersächsisches Landesgesundheitsamt (NLGA)” confirmed our observation of severely escalated sex odds within 40 km distance from the nuclear storage site in Gorleben, Germany.
显示更多 [+] 显示较少 [-]Biofilm formation and microbial community analysis of the simulated river bioreactor for contaminated source water remediation
2012
Xu, Xiang-Yang | Feng, Li-Juan | Zhu, Liang | Xu, Jing | Ding, Wei | Qi, Han-Ying
BACKGROUND, AIM, AND SCOPE: The start-up pattern of biofilm remediation system affects the biofilm characteristics and operating performances. The objective of this study was to evaluate the performances of the contaminated source water remediation systems with different start-up patterns in view of the pollutants removal performances and microbial community succession. METHODS: The operating performances of four lab-scale simulated river biofilm reactors were examined which employed different start-up methods (natural enrichment and artificial enhancement viadischarging sediment with influent velocity gradient increase) and different bio-fillers (Elastic filler and AquaMats® ecobase). At the same time, the microbial communities of the bioreactors in different phases were analyzed by polymerase chain reaction, denaturing gradient gel electrophoresis, and sequencing. RESULTS AND DISCUSSION: The pollutants removal performances became stable in the four reactors after 2 months’ operation, with ammonia nitrogen and permanganate index (CODMn) removal efficiencies of 84.41–94.21% and 69.66–76.60%, respectively. The biomass of mature biofilm was higher in the bioreactors by artificial enhancement than that by natural enrichment. Microbial community analysis indicated that elastic filler could enrich mature biofilm faster than AquaMats®. The heterotrophic bacteria diversity of biofilm decreased by artificial enhancement, which favored the ammonia-oxidizing bacteria (AOB) developing on the bio-fillers. Furthermore, Nitrosomonas- and Nitrosospira-like AOB coexisted in the biofilm, and Pseudomonas sp., Sphaerotilus sp., Janthinobacterium sp., Corynebacterium aurimucosum were dominant in the oligotrophic niche. CONCLUSION: Artificial enhancement via the combination of sediment discharging and influent velocity gradient increasing could enhance the biofilm formation and autotrophic AOB enrichment in oligotrophic niche.
显示更多 [+] 显示较少 [-]Extractability of water-soluble soil organic matter as monitored by spectroscopic and chromatographic analyses
2012
Nkhili, Ezzhora | Guyot, Ghislain | Vassal, Nathalie | Richard, Claire
PURPOSE: Cold and hot water processes have been intensively used to recover soil organic matter, but the effect of extraction conditions on the composition of the extracts were not well investigated. Our objective was to optimize the extraction conditions (time and temperature) to increase the extracted carbon efficiency while minimizing the possible alteration of water extractable organic matter of soil (WEOM). METHOD: WEOM were extracted at 20°C, 60°C, or 80°C for 24 h, 10–60 min, and 20 min, respectively. The different processes were compared in terms of pH of suspensions, yield of organic carbon, spectroscopic properties (ultraviolet–visible absorption and fluorescence), and by chromatographic analyses. RESULTS: For extraction at 60°C, the time 30 min was optimal in terms of yield of organic carbon extracted and concentration of absorbing and fluorescent species. The comparison of WEOM 20°C, 24 h; 60°C, 30 min; and 80°C, 20 min highlighted significant differences. The content of total organic carbon, the value of specific ultraviolet absorbance (SUVA254), the absorbance ratio at 254 and 365 nm (E 2/E 3), and the humification index varied in the order: WEOM (20°C, 24 h) < WEOM (80°C, 20 min) < WEOM (60°C, 30 min). The three WEOM contained common fluorophores associated with simple aromatic structures and/or fulvic-like and common peaks of distinct polarity as detected by ultra performance liquid chromatography. CONCLUSIONS: For the soil chosen, extraction at 60°C for 30 min is the best procedure for enrichment in organic chemicals and minimal alteration of the organic matter.
显示更多 [+] 显示较少 [-]NORMACAT project: normalized closed chamber tests for evaluation of photocatalytic VOC treatment in indoor air and formaldehyde determination
2012
Kartheuser, B. | Costarramone, N. | Pigot, T. | Lacombe, S.
BACKGROUND, AIM: The aims of the NORMACAT project are: to develop tools and unbiased standardized methods to measure the performance and to validate the safety of new materials and systems integrating photocatalysis, to develop new photocatalytic media with higher efficiency and to give recommendations aimed at improving the tested materials and systems. METHOD: To achieve this objective, it was necessary to design standardized test benches and protocols to assess photocatalytic efficiency of materials or systems used in the treatment of volatile organic compounds (VOCs) and odour under conditions close to applications. The tests are based on the validation of robust analytical methods at the parts per billion by volume level that not only follow the disappearance of the initial VOCs but also identify the secondary species and calculate the mineralization rates. RESULTS: The first results of inter-laboratory closed chamber tests, according to XP B44-013 AFNOR standard, are described. The photocatalytic degradation of mixtures of several defined pollutants under controlled conditions (temperature, relative humidity, initial concentration) was carried out in two independent laboratories with the same photocatalytic device and with various analytical procedures. Comparison of the degradation rate and of the mineralization efficiency allowed the determination of the clean air delivery rate in both cases. Formaldehyde was the only by-product detected during photocatalytic test under standardized experimental conditions. The concentration of transient formaldehyde varied according to the initial VOC concentration. Moreover the photocatalytic reaction rate of formaldehyde in mixture with other pollutants was analysed. It was concluded that formaldehyde concentration did not increase with time. CONCLUSION—PERSPECTIVE: This type of experiment should allow the comparison of the performances of different photoreactors and of photocatalytic media under controlled and reproducible conditions against mixtures of pollutants including formaldehyde.
显示更多 [+] 显示较少 [-]Heavy metal contamination in an urban stream fed by contaminated air-conditioning and stormwater discharges
2012
O’Sullivan, Aisling | Wicke, Daniel | Cochrane, Tom
PURPOSE: Urban waterways are impacted by diffuse stormwater runoff, yet other discharges can unintentionally contaminate them. The Okeover stream in Christchurch, New Zealand, receives air-conditioning discharge, while its ephemeral reach relies on untreated stormwater flow. Despite rehabilitation efforts, the ecosystem is still highly disturbed. It was assumed that stormwater was the sole contamination source to the stream although water quality data were sparse. We therefore investigated its water and sediment quality and compared the data with appropriate ecotoxicological thresholds from all water sources. METHODS: Concentrations of metals (Zn, Cu and Pb) in stream baseflow, stormwater runoff, air-conditioning discharge and stream-bed sediments were quantified along with flow regimes to ascertain annual contaminant loads. Metals were analysed by ICP-MS following accredited techniques. RESULTS: Zn, Cu and Pb concentrations from stormflow exceeded relevant guidelines for the protection of 90% of aquatic species by 18-, 9- and 5-fold, respectively, suggesting substantial ecotoxicity potential. Sporadic copper (Cu) inputs from roof runoff exceeded these levels up to 3,200-fold at >4,000 μg L−1 while Cu in baseflow from air-conditioning inputs exceeded them 5.4-fold. There was an 11-fold greater annual Cu load to the stream from air-conditioning discharge compared to stormwater runoff. Most Zn and Cu were dissolved species possibly enhancing metal bioavailability. Elevated metal concentrations were also found throughout the stream sediments. CONCLUSIONS: Environmental investigations revealed unsuspected contamination from air-conditioning discharge that contributed greater Cu annual loads to an urban stream compared to stormwater inputs. This discovery helped reassess treatment strategies for regaining ecological integrity in the ecosystem.
显示更多 [+] 显示较少 [-]Monitoring heavy metal pollution by aquatic plants : A systematic study of copper uptake
2012
Materazzi, S. | Canepari, S. | Aquili, S.
INTRODUCTION: The copper bioaccumulation by the floating Lemna minor and by the completely submerged Ranunculus tricophyllus as a function of exposure time and copper concentration was studied, with the aim of proposing these species as environmental biosensors of the water pollution. RESULTS: The results show that both these aquatic angiosperms are good indicators of copper pollution because the copper uptake is the only function of metal concentration (water pollution). CONCLUSION: Uptake behavior is reported as a function of the time and concentration, based on the results of a 3-year study. Kinetic evaluations are proposed.
显示更多 [+] 显示较少 [-]Changing pollutants to green biogases for the crop food cycle chain
2012
Zong, B. Y. | Xu, F. J. | Zong, B. D. | Zhang, Z. G.
PURPOSE: When fossil fuels on the Earth are used up, which kind of green energy can be used to replace them? Do every bioenergy generation or crop food chain results in environmental pollution? These questions are major concerns in a world facing restricted supplies of energy and food as well as environmental pollutions. To alleviate these issues, option biogases are explored in this paper. MATERIALS AND METHODS: Two types of biogas generators were used for modifying the traditional crop food chain [viz. from atmospheric CO2 photosynthesis to crops, crop stem/husk biowastes (burnt in cropland or as home fuels), to livestock droppings (dumping away), pork and people foods, then to CO2], via turning the biowaste pollutants into green bioenergies. By analyzing the traditional food chain via observation method, the drawbacks of by-product biowastes were revealed. Also, the whole cycle chain was further analyzed to assess its “greenness,” using experimental data and other information, such as the material balance (e.g., the absorbed CO2, investment versus generated food, energy, and wastes). RESULTS AND DISCUSSION: The data show that by using the two types of biogas generators, clean renewable bioenergy, crop food, and livestock meat could be continuously produced without creating any waste to the world. The modification chain largely reduced CO2 greenhouse gas and had a low-cost investment. The raw materials for the gas generators were only the wastes of crop stems and livestock droppings. Thus, the recommended CO2 bioenergy cycle chain via the modification also greatly solved the environmental biowaste pollutions in the world. CONCLUSIONS: The described two type biogases effectively addressed the issues on energy, food, and environmental pollution. The green renewable bioenergy from the food cycle chain may be one of suitable alternatives to fossil and tree fuels for agricultural countries.
显示更多 [+] 显示较少 [-]Geosmin degradation by seasonal biofilm from a biological treatment facility
2012
Xue, Qiang | Shimizu, Kazuya | Sakharkar, Meena Kishore | Utsumi, Motoo | Cao, Gang | Li, Miao | Zhang, Zhenya | Sugiura, Norio
INTRODUCTION: Initial geosmin degradation was closely related to water temperature and natural geosmin concentration of sampling environment. Here, for the first time, we evaluated the biodegradation of geosmin by microorganisms in biofilm from biological treatment unit of actual potable water treatment plant. MATERIALS AND METHODS: At an initial geosmin concentration of 2,500 ng/l, efficient geosmin removal was confirmed throughout the year. Furthermore, in the presence of mixed musty odor compounds (geosmin and MIB) as carbon source, geosmin degradation was enhanced compared to sole carbon source (geosmin alone). RESULTS AND DISCUSSION: PCR-DGGE analysis revealed a rich community structure within the biofilm during rapid geosmin removal period, April. PCA revealed that the significant change in bacterial communities occurred from day 1 to day 2. Two novel geosmin-degrading bacteria were isolated from the biofilm of the biological treatment unit of Kasumigaura Water Purification, Waterworks Department, Japan. They belong to Methylobacterium sp. and Oxalobacteraceae bacterium, respectively. CONCLUSIONS: These studies provide further insights into the unknown microbiological processes that occur during the biological removal of geosmin through water treatment and could facilitate the geosmin bioremediation in contaminated habitats.
显示更多 [+] 显示较少 [-]Acid–base balance and metabolic response of the sea urchin Paracentrotus lividus to different seawater pH and temperatures
2012
Catarino, Ana I. | Bauwens, Mathieu | Dubois, Philippe
PURPOSE: In order to better understand if the metabolic responses of echinoids could be related to their acid–base status in an ocean acidification context, we studied the response of an intertidal sea urchin species, Paracentrotus lividus, submitted to low pH at two different temperatures. METHODS: Individuals were submitted to control (8.0) and low pH (7.7 and 7.4) at 10°C and 16°C (19 days). The relation between the coelomic fluid acid–base status, the RNA/DNA ratio of gonads and the individual oxygen uptake were studied. RESULTS: The coelomic fluid pH decreased with the aquarium seawater, independently of temperature, but this explained only 13% of the pH variation. The coelomic fluid showed though a partial buffer capacity that was not related to skeleton dissolution ([Mg2+] and [Ca2+] did not differ between pH treatments). There was an interaction between temperature and pH on the oxygen uptake (V O2) which was increased at pH 7.7 and 7.4 at 10°C in comparison with controls, but not at 16°C, indicating an upregulation of the metabolism at low temperature and pH. However, gonad RNA/DNA ratios did not differ according to pH and temperature treatments, indicating that even if maintenance of physiological activities has an elevated metabolic cost when individuals are exposed to stress, they are not directly affected during short-term exposure. Long-term studies are needed in order to verify if gonad production/growth will be affected by low pH seawaters exposure.
显示更多 [+] 显示较少 [-]Toxicity of pentachlorophenol to native aquatic species in the Yangtze River
2012
Jin, Xiaowei | Zha, Jinmiao | Xu, Yiping | Giesy, John P. | Wang, Zijian
INTRODUCTION: While the literature is replete with studies of the toxic potency of pentachlorophenol (PCP), site-specific criteria for native aquatic species that can be used in ecological risk assessments has been lacking and application of toxicity information for non-native species is controversial. MATERIALS AND METHODS: In the present study, acute and chronic toxicities of PCP to six aquatic species native to the Yangtze River were determined. The HC5 and HC50 (hazardous concentration for 5% and 50% of species) were derived from dose–response curves for these native aquatic species and were then compared with those derived for non-native species. RESULTS: The acute toxicity values for the native species ranged from 8.8 × 10−2 mg l−1 (Plagiognathops microlepis) to 1.1 mg l−1 (Soirodela polyrhiza), while chronic toxicity values based on no observed effect concentrations (NOECs) ranged from 0.01 mg l−1 (Macrobrachium superbum) to 0.25 mg l−1 (Soirodela polyrhiza). Native aquatic benthos was more sensitive to acute PCP exposure than non-native species. There was no significant difference in NOECs derived from native fish species and those based on non-native fish species. The median acute HC5 and HC50 derived from the toxicity data of native taxa were both less than those derived from non-native taxa. There was no significant difference between chronic HC5s derived from the two sets of taxa. However, the median chronic HC50 derived from native taxa was less than that derived from non-native taxa. CONCLUSION: The study upon which we report here provides site-specific toxicity information developed for native species which can be used for the protection of local aquatic life from a common contaminant, PCP.
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