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Airborne lead levels in the Korean peninsula: characterization of temporal and spatial patterns and cancer risk analysis Full text
2012
Mutlu, Atilla | Lee, Byeong-Kyu
INTRODUCTION: This study collected long-term airborne lead concentrations in the Korean peninsula and analyzed their temporal, spatial, and cancer risk characterization. METHODS: Approximately, 12,000 airborne samples of total suspended particulate (TSP) were collected from 30 ambient air monitoring stations in inland (Daegu, Daejeon, Gwangju, and Seoul) cities and portal cities (Incheon, Busan, and Ulsan) over a period of 7 years (2004–2010). High volume air samplers were employed to collect daily TSP samples during the second week of the consecutive months throughout the entire study period. The concentrations of Pb extracted from the TSP samples were analyzed using either inductively coupled plasma-atomic emission or flame atomic absorption spectrometry. RESULTS: The long-term high mean Pb concentrations were observed in the port cities including Incheon (88 ± 18 ng/m3), Ulsan (61 ± 7 ng/m3), and Busan (58 ± 6 ng/m3). In the temporal analysis, seasonal mean Pb levels were relatively higher in winter and spring than those in summer and fall. In the spatial analysis, the mean Pb levels in spring, winter, and fall from Incheon, which showed the highest seasonal concentrations except summer, were 110 ± 19, 101 ± 18, and 76 ± 23 ng/m3, respectively. In summer, the highest seasonal mean Pb level was observed in the largest industrial city and the second port city, Ulsan (78 ± 15 ng/m3), followed by Incheon (65 ± 13 ng/m3). CONCLUSION: The estimated excess cancer risk analysis showed that inhalation of Pb could result in cancer for one or two persons per million of population in the Korean peninsula.
Show more [+] Less [-]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) Full text
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.
Show more [+] Less [-]Heavy metal contamination in an urban stream fed by contaminated air-conditioning and stormwater discharges Full text
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.
Show more [+] Less [-]Optimization of nitrate reduction by EDTA catalyzed zero-valent bimetallic nanoparticles in aqueous medium Full text
2012
Singh, Kunwar P. | Singh, Arun K. | Gupta, Shikha
The present study aims to investigate the EDTA catalyzed reduction of nitrate (NO 3 − ) by zero-valent bimetallic (Fe–Ag) nanoparticles (ZVBMNPs) in aqueous medium and to enumerate the effect of temperature, solution pH, ZVBMNPs dose and EDTA concentration on NO 3 − reduction. Batch experimental data were generated using a four-factor Box–Behnken design. Optimization modeling was performed using the response surface method for maximizing the reduction of NO 3 − by ZVBMNPs. Significance of the independent variables and their interactions were tested by the analysis of variance and t test statistics. The model predicted maximum reduction capacity (340.15 mg g−1 NO 3 − ) under the optimum conditions of temperature, 60 °C; pH 4; dose, 1.0 g l−1; and EDTA concentration, 2.0 mmol l−1 was very close to the experimental value (338.62 mg g−1) and about 16 % higher than the experimentally determined capacity (291.32 mg g−1). Study demonstrated that ZVBMNPs had higher reduction efficiency than Fe0 nanoparticles for NO 3 − . EDTA significantly enhanced the NO 3 − reduction by ZVBMNPs. The EDTA catalyzed reduction of NO 3 − by ZVBMNPs can be employed for the effective decontamination of water.
Show more [+] Less [-]Establishing potential links between the presence of alkylphenolic compounds and the benthic community in a European river basin Full text
2012
Brix, Rikke | López-Doval, Julio | Ricart, Marta | Guasch, Helena | de Alda, Miren Lopez | Muñoz, Isabel | Orendt, Claus | Romaní i Cornet, Anna M. | Sabater, Sergi | Barceló, Damià
INTRODUCTION: Concentrations of alkylphenolic compounds (APCs) in water and sediments were related to the composition and functional descriptors of the benthic community (biofilm and macroinvertebrates). MATERIALS AND METHODS: Samples were collected in four sampling campaigns at seven sampling points in the lower Llobregat catchment area (NE Spain). Water and sediment samples underwent chemical target analysis for nine APCs, which are known to disrupt the endocrine system. RESULTS AND DISCUSSIONS: APCs were the main stressors on the diatom community but not on the macroinvertebrate community. CONCLUSIONS: Benthic invertebrates were mostly affected by the general physicochemical water characteristics (where conductivity was a surrogate). Nonylphenol only had an influence on the diatom community in water but not in the remaining compartments, probably because of the low concentrations observed in the environment.
Show more [+] Less [-]Influence of pH and ozone dose on the content and structure of haloacetic acid precursors in groundwater Full text
2012
Molnar, Jelena | Agbaba, Jasmina | Dalmacija, Božo | Rončević, Srđan | Prica, Miljana | Tubić, Aleksandra
This study investigated the effects of pH (6–10) and ozone dose [0.4–3.0 mg O3/mg dissolved organic carbon (DOC)] on the content and structure of haloacetic acid (HAA) precursors in groundwater rich in natural organic matter (NOM; DOC 9.85 ± 0.18 mg/L) during drinking water treatment. The raw water was ozonated in a 2 L glass column. NOM fractionation was carried out using XAD resins. HAA formation potential (HAAFP) was determined according to standard EPA Method 552. NOM characterization revealed it is mostly hydrophobic (65 % fulvic and 14 % humic acids). Hydrophobic NOM significantly influences HAA formation, as confirmed by the high HAAFP (309 ± 15 μg/L). Ozonation at pH 6–10 led to changes in NOM structure, i.e. complete humic acid oxidation, and increased the hydrophilic NOM fraction content (65–90 % achieved using 3.0 mg O3/mg DOC). The highest degree of NOM oxidation and HAA precursor removal was achieved at pH 10 (up to 68 % HAAFP). Ozonation pH influenced the distribution of HAA precursor content, as increasing the pH from 6 to 10 increased the reactivity of the hydrophilic fraction, with the HAAFP increasing from 19.1 ± 6.0 μg/mg DOC in raw water to 152 ± 8 μg/mg DOC in ozonated water. The degree of HAA precursor removal depends on the dominant oxidation mechanism, which is related to the applied ozone dose and the pH of the oxidation process. Ozonation at pH 10 favours the mechanism of radical NOM oxidation and was the most effective for HAAFP reduction, with the efficacy of the process improving with increasing ozone dose.
Show more [+] Less [-]Cellular and molecular damage of Phanerochaete chrysosporium by the oxidation hair dyes Full text
2012
Xiong, Hongxia | Zhou, Qixing
INTRODUCTION: The toxic effect of the oxidation hair dyes on Phanerochaete chrysosporium was investigated by exposure of this fungus in a nitrogen-limited culture medium to various concentrations of the oxidation hair dyes. RESULTS: The results showed that both the size and the dry weight of the mycelial pellets of P. chrysosporium could be reduced when the concentration of the oxidation hair dyes was higher than 300 mg/L. By using the AFLP analysis and the UPGMA dendrogram, the DNA damage of P. chrysosporium by the oxidation hair dyes was also detected. Comparing with that in the control, the percent polymorphism under different concentrations of the oxidation hair dyes increased. In the meantime, the DNA similarity was decreased, which meant that the DNA damage was aggravated with an increase in the concentrations of the oxidation hair dyes. CONCLUSION: Thus, as an environmental pollutant, the oxidation hair dyes have a toxic effect on P. chrysosporium at both cellular and molecular levels.
Show more [+] Less [-]Risk posed by chlorinated organic compounds in Abu Qir Bay, East Alexandria, Egypt Full text
2012
Khairy, Mohammed Abd EL-Hamid | Kolb, Marit | Mostafa, Alaa R. | EL-Fiky, Anwar | Bahadir, M.
INTRODUCTION: In Egypt, the picture of threats to humans and the environment from the exposure to organic pollutants is still incomplete. Thus the objectives of this study were to assess the occurrence and distribution of polychlorinated biphenyls (PCBs), organochlorine pesticides, and chlorpyrifos in sediments and mussels of Abu Qir Bay and their risks for environment and human health. MATERIALS AND METHODS: Twenty-three different compounds organochlorines were determined in 20 surfacial sediment and 10 mussel samples by gas chromatography-electron capture detector. A Screening Level Ecological Risk Assessment (SLERA) and a Human Health Risk Assessment (HHRA) were performed with the data. RESULTS AND DISCUSSION: ΣDDT (DDT, DDE, DDD) (average concentration 27 µg/kg dw) dominated the detected organic pollutants in the sediments, followed by CHLs (chlordane, heptachlor, heptachloro epoxide), hexachlorocyclohexane, chlorpyrifos, endosulfane, dieldrine, Σ6 PCBs, aldrine, hexachlorobenzene, pentachlorobenzene, methoxychlor, and mirex. In general, concentrations of Σ6 PCBs in mussels were higher than their corresponding sediment concentrations reflecting their relatively high bioavailability and bioaccumulative potential. However, concentrations of the organochlorine pesticides in mussels were lower than their corresponding sediment samples. Nevertheless, the SLERA on the bay sediments revealed that adverse ecological effects to benthic species are expected to occur whereas the HHRA showed that adverse health effects are not expected to occur from the consumption of the mussels. CONCLUSIONS: With the help of a SLERA, it was possible to indicate which class of chlorinated organic compounds is of highest concern to assess and to improve the environmental quality of the bay. Monitoring of organochlorines and chlorpyrifos would be needed to control the future trend of pollution.
Show more [+] Less [-]Isolation and characterization of 3-nitrophenol-degrading bacteria associated with rhizosphere of Spirodela polyrrhiza Full text
2012
Kristanti, Risky Ayu | Kanbe, Masahiro | Hadibarata, Tony | Toyama, Tadashi | Tanaka, Yasuhiro | Mori, Kazu-hiro
INTRODUCTION: The accelerated biodegradation of 3-nitrophenol (3-NP) in the rhizosphere of giant duckweed (Spirodela polyrrhiza) was investigated. MATERIALS AND METHODS: Biodegradation of 3-nitrophenol in the rhizosphere of a floating aquatic plant, S. polyrrhiza, was investigated by using three river water samples supplemented with 10 mg l−1 of 3-NP. Isolation and enrichment culture of 3-NP-degrading bacteria were performed in basal salts medium containing 3-NP (50 mg l−1). The isolated strains were physiologically and phylogenetically characterized by using an API20NE kit and 16S rRNA gene sequencing. RESULTS AND DISCUSSION: Accelerated removal of 3-NP (100%) was observed in river water samples with S. polyrrhiza compared with their removal in plant-free river water. Also, 3-NP persisted in an autoclaved solution with aseptic plants, suggesting that the accelerated 3-NP removal resulted largely from degradation by bacteria inhabiting the plant rather than from adsorption and uptake by the plant. We successfully isolated six and four strains of 3-NP-degrading bacteria from the roots of S. polyrrhiza and plant-free river water, respectively. Phylogenetic analysis based on 16S rRNA gene divided the 3-NP-degrading bacteria into two taxonomic groups: the genera Pseudomonas and Cupriavidus. The strains belonging to the genus Cupriavidus were only isolated from the roots of duckweed. All strains isolated from the roots utilized 3-NP (0.5 mM) as a sole carbon and energy source, indicating that they could have contributed to the accelerated degradation of 3-NP in the rhizosphere of S. polyrrhiza. CONCLUSIONS: The rhizoremediation using S. polyrrhiza and its rhizosphere bacteria can be an effective strategy for cleaning up the 3-NP-contaminated surface waters.
Show more [+] Less [-]Geosmin degradation by seasonal biofilm from a biological treatment facility Full text
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.
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