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Surface ozone comparison conducted in two rural areas in central-southern Spain Full text
2012
Notario, Alberto | Díaz-de-Mera, Yolanda | Aranda, Alfonso | Adame, José Antonio | Parra, Alfonso | Romero, Eugenio | Parra, Jesús | Muñoz, Fernando
PURPOSE: The purpose of this work is to contribute to the understanding of the photochemical air pollution analysing the levels and temporal variations of surface ozone in two rural areas situated in central-southern Spain. METHOD: The study is based on ozone hourly data recorded during the overall period between January 2008 and November 2009. The seasonal and daily ozone cycles as well as the number of exceedances of the threshold established in the European Ozone Directive have been calculated and analysed. RESULTS: This study presents the first ozone data registered at these two rural sites in the Iberian Peninsula plateau. Ozone shows a clear seasonal variation with the lowest values in January and November. High ozone concentrations are interrelated with high radiation intensities, temperature and wind directions. The information threshold defined in the European Ozone Directives was exceeded six times, while the limit for protection of human health was exceeded more than 40 times. The limits to protect the vegetation were also exceeded. CONCLUSIONS: Porzuna (near Cabañeros National Park) presents higher ozone levels than Argamasilla during the night-time and during the daytime of the summer months. Ozone levels are lower in Argamasilla probably due to fresh emissions from the close industrial area of Puertollano. The ozone exceedances of the limits defined in the Ozone Directive point out an ozone problem in this rural region.
Show more [+] Less [-]Occurrence, distribution, and seasonal variation of estrogenic compounds and antibiotic residues in Jiulongjiang River, South China Full text
2012
Zhang, Xian | Zhang, Dandan | Zhang, Han | Luo, Zhuanxi | Yan, Changzhou
BACKGROUND AND PURPOSE: Estrogenic compounds and antibiotic residues in environment are receiving significant attention because of their potential adverse effects on ecosystems and human health. The objectives of this study were to determine the occurrence and seasonal variability of eight kinds of estrogenic compounds and 14 antibiotics. The study developed an occurrence database of the estrogenic compounds and antibiotics in spatial and temporal scale in Jiulongjiang River, South China, to provide useful information for environmental management of this region. METHODS: Eight estrogenic compounds and 14 antibiotic compounds were detected in Jiulongjiang River from 19 sampling sites during high-flow and low-flow season in surface water. The samples were preconcentrated by solid-phase extraction for analysis. Eight estrogenic compounds were analyzed by gas chromatography mass spectrometry (Agilent 7890A-5975C), and antibiotics were determined by liquid chromatography-tandem mass spectrometry (LC–MS/MS) system (ABI 3200 Q TRAP). RESULTS: All target compounds could be detected, except 17α-ethynylestradiol, sulfamerazine, and ofloxacin. The median concentrations for seven estrogenic compounds ranged from 6.00 to 610.72 ng/L, with the detection frequency range of 16.00–100%. However, the detection frequencies of 13 antibiotics detected varied from 50% to 100%, with the median concentrations ranged from 0.89 to 117.97 ng/L. Seasonal variations were obvious for most estrogenic compounds in Jiulongjiang River, except for octylphenol and estriol. There were significant (P < 0.001) differences for three tetracyclines, sulfadiazine, and sulfamethoxazole between in low-flow season and in high-flow season. Besides, spatially considerable variations in the concentrations were observed for antibiotics, nonylphenol, octylphenol, and bisphenol A. CONCLUSION: The Jiulongjiang River water was more seriously contaminated by diethylstilbestrol, estrone, sulfamethazine, and tetracyclines. Higher overall concentration levels of estrogenic compounds and antibiotics were detected in low-flow water than those in high-flow water. The pollution of estrogenic compounds and antibiotics in Jiulongjiang River mainly came from municipal sewage and livestock breeding activities.
Show more [+] Less [-]Detection of antibacterial-like activity on a silica surface: fluoroquinolones and their environmental metabolites Full text
2012
Lewis, Gareth | Juhasz, Albert | Smith, Euan
BACKGROUND, SCOPE, AND AIMS: Antibacterial fluoroquinolones (FQs) are third-generation antibiotics that are commonly used as therapeutic treatments of respiratory and urinary tract infections. They are used far less in intensively farmed animal production systems, though their use may be permitted in the veterinary treatments of flocks or in medicated feeds. When used, only a fraction of ingested parent FQ actually reaches the in vivo target site of infection, while the remainder is excreted as the parent FQ and its metabolized products. In many species’ metabolism, enrofloxacin (EF) is converted into ciprofloxacin (CF) while both FQs are classified as parent FQs in human treatments. It is therefore likely that both FQs and their metabolic products will contribute to a common pool of metabolites in biological wastes. Wastes from intensive farming practices are either directly applied to agricultural land without treatment or may be temporarily stored prior to disposal. However, human waste is treated in sewage treatment plants (STPs) where it is converted into biosolids. In the storage or treatment process of STPs, FQs and their in vivo metabolites are further converted into other environmental metabolites (FQEMs) by ex vivo physicochemical processes that act and interact to produce complex mixtures of FQEMs, some of which have antibacterial-like activities. Biosolids are then often applied to agricultural land as a fertilizer amendment where FQs and FQEMs can be further converted into additional FQEMs by soil processes. It is therefore likely that FQ-contaminated biowaste-treated soils will contain complex mixtures of FQEMs, some of which may have antibacterial-like activities that may be expressed on bacteria endemic to the receiving agricultural soil environment. Concern has arisen in the scientific and in the general community that repeated use of FQ-contaminated biowaste as fertilizer amendments of nutrient-impoverished agricultural land may create a selective environment in which FQ-resistant bacteria might grow. The likelihood of this happening will depend, to some extent, on whether bioactive FQEMs are first synthesized from the parent FQs by the action and interaction of in vivo and ex vivo processes producing bioactive FQEMs in biowastes and biosolids. The postulated creation of a selective environment will also depend, in part, on whether such bioactive FQEMs are biologically available to bacteria, which may, in turn, be influenced by soil type, amendment regime, and the persistence of the bioactive FQEMs. Additionally, soil bacteria and soil processes may be affected in different ways or extents by bioactive FQEMs that could possibly act additively or synergistically at ecological targets in these non-target bacteria. This is an important consideration, since, while parent FQs have well-defined ecological targets (DNA gyrase and topoisomerase IV) and modes of bactericidal action, the FQEMs and their possible modes of action on the many different species of soil bacteria is less well studied. It is therefore understandable that there is a lack of conclusive evidence directly attributing biosolid usage to any increase in FQ-resistant bacteria detected in biowaste-amended agricultural soil. However, a lack of evidence may simply imply that a causal relationship between biosolid usage programs and any detection of low levels of FQ-resistant bacteria in soils has yet to be established, rather than an assumption of no relationship whatsoever. Based on results presented in this paper, the precautionary principle should be applied in the usage of FQ-contaminated biosolids as fertilizer amendments of agricultural land. The aim of this research was to test whether any bioactive FQEMs of EF could be synthesized by aerobic fermentation processes using Mycobacterium gilvum (American Tissue Culture Collection) and a mixed culture of microorganisms derived from an agricultural soil. High-performance thin-layer chromatography (HPTLC) and bioautography were tested as screening techniques in the detection and analysis of bioactive FQEMs. MATERIALS AND METHODS: FQEMs derived from M. gilvum and mixed (soil) culture aerobic ferments were fractionated using preparative HPTLC. A standard strain of Escherichia coli was then used as the reporter organism in a bioautography assay in the detection of bioactive-FQEMs on a mid-section of the HPTLC plate. Plate sections were reassembled, and a photograph was taken under low-intensity ultraviolet (UV) light to reveal regions that contained analytes that had UV chromophores and antibacterial-like activities. RESULTS AND DISCUSSION: Many fractionated FQEMs displayed antibacterial-like activity while bound to silica gel HPTLC plates. These results also provide evidence that sufficient quantities of biologically active FQEMs were biologically available from a silica gel surface to prevent the adherent growth of E. coli. Six to seven FQEMs derived from EF using aerobic fermentation processes had antibacterial-like activities, while two FQEMs were also detectable using UV light. Furthermore, similar banding patterns of antibacterial-like activity were observed in both the monoculture (M. gilvum) and mixed culture bioautography assays, indicating that similar processes operated in both aerobic fermentations, either producing similar biologically active FQEMs or biologically active FQEMs that had similar physicochemical properties in both ferments. The simplest explanation for these findings is that the tested agricultural soil also contained mycobacteria that metabolized EF in a similar way to the purchased standard monoculture M. gilvum. Additionally, the marked contrast between the bioautography results and the UV results indicated that the presence of UV chromophores is not a prerequisite for the detection of antibacterial-like activity. CONCLUSIONS: A reliance on spectrophotometric techniques in the detection of bioactive FQEMs in the environment may underestimate component antibacterial-like activity and, possibly, total antibacterial-like activity expressed by EF and its FQEMs. The described bioautography method provides a screening technique with which antibacterial-like activities derived from EF and possibly other FQs can be detected directly on silica gel HPTLC plates. RECOMMENDATIONS: It is recommended that both bioassay and instrumental analytical techniques be used in any measurement of hazard and risk relating to antibacterial-like activities in the environment that are derived from fluoroquinolone antibiotics and their environmental metabolites.
Show more [+] Less [-]Lethal effects on different marine organisms, associated with sediment–seawater acidification deriving from CO₂ leakage Full text
2012
Basallote, M. D. | Rodríguez-Romero, A. | Blasco, J. | DelValls, A. | Riba, I.
Lethal effects on different marine organisms, associated with sediment–seawater acidification deriving from CO₂ leakage Full text
2012
Basallote, M. D. | Rodríguez-Romero, A. | Blasco, J. | DelValls, A. | Riba, I.
CO₂ leakages during carbon capture and storage in sub-seabed geological structures could produce potential impacts on the marine environment. To study lethal effects on marine organisms attributable to CO₂ seawater acidification, a bubbling CO₂ system was designed enabling a battery of different tests to be conducted, under laboratory conditions, employing various pH treatments (8.0, 7.5, 7.0, 6.5, 6.0, and 5.5). Assays were performed of three exposure routes (seawater, whole sediment, and sediment elutriate). Individuals of the clam (Ruditapes philippinarum) and early-life stages of the gilthead seabream, Sparus aurata, were exposed for 10 days and 72 h, respectively, to acidified clean seawater. S. aurata larvae were also exposed to acidified elutriate samples, and polychaete organisms of the specie Hediste diversicolor and clams R. philippinarum were also exposed for 10 days to estuarine whole sediment. In the fish larvae elutriate test, 100 % mortality was recorded at pH 6.0, after 48 h of exposure. Similar results were obtained in the clam sediment exposure test. In the other organisms, significant mortality (p < 0.05) was observed at pH values lower than 6.0. Very high lethal effects (calculating L[H⁺]50, defined as the H⁺ concentration that causes lethal effects in 50 % of the population exposed) were detected in association with the lowest pH treatment for all the species. The implication of these results is that a severe decrease of seawater pH would cause high mortality in marine organisms of several different kinds and life stages. The study addresses the potential risks incurred due to CO₂ leakages in marine environments.
Show more [+] Less [-]Lethal effects on different marine organisms, associated with sediment-seawater acidification deriving from CO2 leakage Full text
2012
Basallote, M. Dolores | Rodríguez-Romero, Araceli | Blasco, Julián | Del Valls, T. A. | Riba, Inmaculada
CO2 leakages during carbon capture and storage in sub-seabed geological structures could produce potential impacts on the marine environment. To study lethal effects on marine organisms attributable to CO2 seawater acidification, a bubbling CO2 system was designed enabling a battery of different tests to be conducted, under laboratory conditions, employing various pH treatments (8. 0, 7. 5, 7. 0, 6. 5, 6. 0, and 5. 5). Assays were performed of three exposure routes (seawater, whole sediment, and sediment elutriate). Individuals of the clam (Ruditapes philippinarum) and early-life stages of the gilthead seabream, Sparus aurata, were exposed for 10 days and 72 h, respectively, to acidified clean seawater. S. aurata larvae were also exposed to acidified elutriate samples, and polychaete organisms of the specie Hediste diversicolor and clams R. philippinarum were also exposed for 10 days to estuarine whole sediment. In the fish larvae elutriate test, 100 % mortality was recorded at pH 6. 0, after 48 h of exposure. Similar results were obtained in the clam sediment exposure test. In the other organisms, significant mortality (p < 0.05) was observed at pH values lower than 6. 0. Very high lethal effects (calculating L[H+]50, defined as the H+ concentration that causes lethal effects in 50 % of the population exposed) were detected in association with the lowest pH treatment for all the species. The implication of these results is that a severe decrease of seawater pH would cause high mortality in marine organisms of several different kinds and life stages. The study addresses the potential risks incurred due to CO2 leakages in marine environments. © 2012 Springer-Verlag. | The work described was supported partially by grants from the Spanish Ministry of Science and Innovation (CTM2008-06344-C03-02/ TECNO, CTM2008-06344-C03-03/TECNO, and CTM2011-28437-C02-02) and by grant P08-556 RNM 3924 from the Regional Government of Andalusia (Junta de Andalucía). | Peer Reviewed
Show more [+] Less [-]Physiological effects of arsenate on transplant thalli of the lichen Pyxine cocoes (Sw.) Nyl Full text
2012
Bajpai, Rajesh | Pandey, A. K. | Deeba, F. | Upreti, D. K. | Nayaka, S. | Pandey, V.
INTRODUCTION: The changes in photosynthetic pigments, chlorophyll fluorescence, protein content, and antioxidant enzymes were investigated in a foliose lichen Pyxine cocoes, which was subjected to increasing concentrations of arsenate. METHODS: The arsenate concentrations of 10, 25, 50, 75, 100, and 200 μM were sprayed every alternate day on the lichen thallus. The thalli were then harvested on 10, 20, 30, and 45 days. RESULTS: The quantity of photosynthetic pigments exhibited a decreasing trend till 20 days but increased from 30 days onwards. Concomitantly, chlorophyll fluorescence also showed a decreasing trend with increasing arsenic treatment duration as well as concentration. The higher concentration of arsenate was found to be deleterious to the photosynthesis of lichen as the chlorophyll fluorescence and the amount of pigments decreased significantly. The protein content of lichen increased uninterruptedly as the concentration of arsenate as well as duration of treatment increased. The activities of superoxide dismutase and ascorbate peroxide increased initially at lower concentration of arsenate but declined at higher concentrations and longer duration of treatment. CONCLUSIONS: The catalase activity was found to be most susceptible to arsenate stress as its activity started declining from very beginning of the experiment. P. cocoes also proved to be an excellent accumulator of arsenate whose concentration increased in the thallus corresponding to its increase in the treatment and duration. Thus, it can be utilized for active biomonitoring of arsenic pollution.
Show more [+] Less [-]Comparison of two wild rodent species as sentinels of environmental contamination by mine tailings Full text
2012
Tovar-Sánchez, E. | Cervantes, L. T. | Martínez, C. | Rojas, E. | Valverde, M. | Ortiz-Hernández, M. L. | Mussali-Galante, P.
BACKGROUND: Contamination with heavy metals is among the most hazardous environmental concerns caused by mining activity. A valuable tool for monitoring these effects is the use of sentinel organisms. Particularly, small mammals living inside mine tailings are an excellent study system because their analysis represents a realistic approach of mixtures and concentrations of metal exposure. PURPOSE: We analyzed metal tissue concentrations and DNA damage levels for comparison between genders of a sentinel (Peromyscus melanophrys) and a nonsentinel (Baiomys musculus) species. Also, the relationship between DNA damage and the distance from the contamination source was evaluated. METHODS: This study was conducted in an abandoned mine tailing at Morelos, Mexico. Thirty-six individuals from both species at the exposed and reference sites were sampled. Metal concentrations in bone and liver of both species were analyzed by atomic absorption spectrophotometry, and DNA damage levels were assayed using the alkaline comet assay. RESULTS: In general, concentrations of zinc, nickel, iron, and manganese were statistically higher in exposed individuals. A significant effect of the organ and the site on all metal tissue concentrations was detected. Significant DNA damage levels were registered in the exposed group, being higher in B. musculus. Females registered higher DNA damage levels than males. A negative relationship between distance from the mine tailing and DNA damage in B. musculus was observed. CONCLUSIONS: We consider that B. musculus is a suitable species to assess environmental quality, especially for bioaccumulable pollutants—such as metals—and recommend that it may be considered as a sentinel species.
Show more [+] Less [-]Contribution of anthropogenic aerosols in direct radiative forcing and atmospheric heating rate over Delhi in the Indo-Gangetic Basin Full text
2012
Srivastava, Atul K. | Singh, Sachchidanand | Tiwari, S. | Bisht, D. S.
INTRODUCTION: The present work is aimed to understand direct radiation effects due to aerosols over Delhi in the Indo-Gangetic Basin (IGB) region, using detailed chemical analysis of surface measured aerosols during the year 2007. METHODS: An optically equivalent aerosol model was formulated on the basis of measured aerosol chemical compositions along with the ambient meteorological parameters to derive radiatively important aerosol optical parameters. The derived aerosol parameters were then used to estimate the aerosol direct radiative forcing at the top of the atmosphere, surface, and in the atmosphere. RESULTS: The anthropogenic components measured at Delhi were found to be contributing ∼72% to the composite aerosol optical depth (AOD0.5 ∼0.84). The estimated mean surface and atmospheric forcing for composite aerosols over Delhi were found to be about −69, −85, and −78 W m−2 and about +78, +98, and +79 W m−2 during the winter, summer, and post-monsoon periods, respectively. The anthropogenic aerosols contribute ∼90%, 53%, and 84% to the total aerosol surface forcing and ∼93%, 54%, and 88% to the total aerosol atmospheric forcing during the above respective periods. The mean (±SD) surface and atmospheric forcing for composite aerosols was about −79 (±15) and +87 (±26) W m−2 over Delhi with respective anthropogenic contributions of ∼71% and 75% during the overall period of observation. CONCLUSIONS: Aerosol induced large surface cooling, which was relatively higher during summer as compared to the winter suggesting an increase in dust loading over the station. The total atmospheric heating rate at Delhi averaged during the observation was found to be 2.42 ± 0.72 K day−1, of which the anthropogenic fraction contributed as much as ∼73%.
Show more [+] Less [-]The seasonal and spatial patterns of ingestion of polyfilament nylon fragments by estuarine drums (Sciaenidae) Full text
2012
Dantas, David V. | Barletta, Mario | da Costa, Monica Ferreira
INTRODUCTION: Artisanal fisheries in tropical estuaries are an important economic activity worldwide. However, gear (e.g. ropes, nets, buoys, crates) and vessels are often in use under dangerous conditions. Polyfilament nylon ropes are used until they are well beyond human and environmental safety limits. Severe wear and tear results in the contamination of the environment with micro-fragments. The spread of these fragments in the marine environment and their ingestion by the biota are documented in the scientific literature and are increasing concerns. The aim of this study was to evaluate the ingestion of plastic fragments by two fish (drum) species in relation to seasonal, habitat and fish size–class variation. MATERIALS AND METHODS: The stomach contents of 569 individuals of Stellifer brasiliensis and Stellifer stellifer from the main channel of the Goiana Estuary were examined to identify variation in the number and the weight of plastic fragments and relate this variation to differences among the seasons (early dry, late dry, early rainy and late rainy), the habitats within the estuary (upper, middle and lower) and the size classes of the fish (juveniles, sub-adults and adults). RESULTS: Plastic fragments were found in 7.9% of the individuals of these two drum species captured from December 2005 to August 2008. Nylon fragments occurred in 9.2% of S. stellifer and 6.9% of S. brasiliensis stomachs. The highest number of nylon fragments ingested was observed in adults during the late rainy season in the middle estuary. DISCUSSION: Blue polyfilament nylon ropes are used extensively in fisheries and can be lost, inappropriately discarded or damaged during use in the estuary. These fragments were the only type of plastic detected during this study. The ingestion of nylon fragments by fish probably occurred during the animals’ normal feeding activities. During the rainy season, the discharge of freshwater transports nylon fragments to the main channel and makes the fragments more available to fish. Fishery activities are responsible for a significant amount of the marine debris found in the estuary. CONCLUSIONS: The ingestion of fragments of nylon threads by fish is a demonstrated form of pollution in the Goiana Estuary. The physiological and toxicological consequences of the ingestion of this type of debris are unknown, as is the actual extent of the problem worldwide. The solutions to the problem are in the hands of authorities and communities alike because the good care and timely replacement of gear requires education, investment and effective policies.
Show more [+] Less [-]Influence of enumeration time periods on analyzing colonization features and taxonomic relatedness of periphytic ciliate communities using an artificial substratum for marine bioassessment Full text
2012
Zhang, Wei | Xu, Henglong | Jiang, Yong | Zhu, Mingzhuang | Al-Rasheid, Khaled A. S.
Colonization features and taxonomic relatedness measures of ciliate communities have been used as useful indicators for marine bioassessment. The influence of enumeration time periods on analyzing colonization features measures of periphytic ciliate communities was studied in coastal waters of the Yellow Sea, northern China, during the period of May–June 2010. Ciliated protozoan samples were collected at depths of 1 m using an artificial substratum and were analyzed with different enumeration schemes. The ciliate species were identified using living observation and silver impregnation. Data analyses were conducted using a range of multivariate statistical routines. Enumeration time periods represented a strong influence on analyzing both colonization and taxonomic relatedness features of periphytic ciliate communities, although no significant changes occurred in colonization patterns between two enumeration schemes (within 24 and 24–48 h after sampling). The delayed enumeration (within 24–48 h) may result in the species richness, individual abundance, colonization rate decreasing to standard errors of >10 % in samples with almost all colonization ages, and in the similarities of the communities being reduced to 11–38 %. However, the species biodiversity (e.g., species diversity and evenness, except species richness) and taxonomic relatedness (taxonomic diversity, taxonomic distinctness and average taxonomic distinctness, except variation in taxonomic distinctness) measures of periphytic ciliate communities were weakly sensitive to disturbance from the delayed enumeration, achieving standard errors of <10 and <5 % during the colonization periods, respectively. These results suggest that the enumeration should be completed as soon as possible within 24 h after sampling to analyze colonization and taxonomic relatedness features of periphytic ciliate communities, and that the species diversity and taxonomic distinctness measures can be used on a robust bioindicator with weak dependence on enumeration time limits for monitoring programs and ecological investigations in marine ecosystems.
Show more [+] Less [-]Water pollution in Asia: the urgent need for prevention and monitoring. Full text
2012
Evans, A. | Hanjra, Munir A. | Jiang, Y. | Qadir, Manzoor | Drechsel, Pay