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Bioavailability and Analytical Measurement of Copper Residuals in Sediments Полный текст
2013
Willis, Ben E. | Alley, Bethany L. | Rodgers, John H., Jr
Analytical measurements are commonly used to screen for toxicity or lack of toxicity from sediment-associated copper. Comparisons of analytical measurements with toxicological responses can be useful for determining the practicality of analytical measurements for assessing the toxicity of copper in sediments. The purpose of this research was to determine the utility of method detection limits (MDLs; i.e., minimum concentration of an analyte such as copper that can be measured with 99 % confidence with a specific analytical method and matrix) to predict the bioavailability of copper in five different sediments. The specific objectives of this research were to (1) select and characterize five sediments with different characteristics, (2) amend and measure a range of copper concentrations in the five sediments to determine MDLs and bioavailability of copper amendments in those sediments, (3) discern relationships with sediment characteristics to MDLs and bioavailability of copper in the five sediments, and (4) compare MDLs and observed toxicity to Hyalella azteca Saussure as an indicator of copper bioavailability in the five sediments. The lowest copper concentrations that elicited an observable adverse effect ranged from 15 to 550 mg Cu/kg, and the MDLs ranged from 1.5 to 6 mg Cu/kg. The MDLs and measured copper concentrations were not adequately predictive of the bioavailability and toxicity of copper in the five sediments. No adverse effects were observed for H. azteca exposed for 10 days to the sediment from California with simultaneously extractable metals > acid-volatile sulfides. Since the lowest observed effects concentrations of copper in the five sediments ranged two orders of magnitude, the National Oceanic and Atmospheric Administration screening values (threshold and probable effect levels) were not predictive of H. azteca responses to the copper-amended sediments.
Показать больше [+] Меньше [-]Removal of Anthracene from Recently Contaminated and Aged Soils Полный текст
2013
Delgado-Balbuena, Laura | Romero-Tepal, Elda M. | Luna-Guido, Marco L. | Marsch, Rodolfo | Dendooven, Luc
Remediation of anthracene from soil was faster in the topsoil than in the lower layers. It was not clear whether this was due to a higher anthracene bioavailability or an increased microbial degradation in the topsoil layer. Therefore, an arable soil was contaminated with 500 mg anthracene kg⁻¹ dry soil, and its removal was monitored with an exhaustive technique and with n-butanol to determine its bioavailability in three layers. Additionally, part of the contaminated soil was stored aerobically for 112 days (considered the aged soil), and the anthracene was monitored thereafter. After 112 days, 360 mg anthracene kg⁻¹ was removed from the soil, but its dissipation was not affected by the layer, depth, and fluctuations in water content or the interaction between. In the aged soil stored for 112 days, only 170 mg anthracene kg⁻¹ was removed. In the subsequent incubation of the aged soil, 273 mg anthracene kg⁻¹ was removed within 28 days, and after 112 days, no contaminant was detectable in the soil. An additional experiment confirmed the hypothesis that simply mixing the soil accelerated the removal of anthracene. Mixing the soil every 7 days removed all anthracene from the soil within 28 days, while in the undisturbed soil, 301 mg anthracene kg⁻¹ was still extractable. It can be concluded that mixing the soil accelerated the removal of anthracene, but fluctuations in water content did not. The anthracene extracted with n-butanol was not related to the amount removed and is thus not a good indicator of bioavailability of anthracene in soil.
Показать больше [+] Меньше [-]Trace Metal Budgets for Forested Catchments in Europe—Pb, Cd, Hg, Cu and Zn Полный текст
2013
Bringmark, Lage | Lundin, Lars | Augustaitis, Algirdas | Beudert, Burkhard | Dieffenbach-Fries, Helga | Dirnböck, Thomas | Grabner, Maria-Theresia | Hutchins, Mike | Kram, Pavel | Lyulko, Iraida | Ruoho-Airola, Tuija | Váňa, Milan
Input/output budgets for cadmium (Cd), lead (Pb) and mercury (Hg) in the years 1997–2011 were monitored and determined for 14 small forest-covered catchments across Europe as part of the Integrated Monitoring program on the effects of long-range pollutants on ecosystems. Metal inputs were considered to derive from bulk deposition, throughfall and litterfall. Outputs were estimated from run-off values. Litterfall plus throughfall was taken as a measure of the total deposition of Pb and Hg (wet + dry) on the basis of evidence suggesting that, for these metals, internal circulation is negligible. The same is not true for Cd. Excluding a few sites with high discharge, between 74 and 94 % of the input Pb was retained within the catchments; significant Cd retention was also observed. High losses of Pb (>1.4 mg m⁻² year⁻¹) and Cd (>0.15 mg m⁻² year⁻¹) were observed in two mountainous Central European sites with high water discharge. All other sites had outputs below or equal to 0.36 and 0.06 mg m⁻² year⁻¹, respectively, for the two metals. Almost complete retention of Hg, 86–99 % of input, was reported in the Swedish sites. These high levels of metal retention were maintained even in the face of recent dramatic reductions in pollutant loads.
Показать больше [+] Меньше [-]Competitive Removal of Cd²⁺ and Hg ²⁺ Ions from Water Using Titanosilicate ETS-4: Kinetic Behaviour and Selectivity Полный текст
2013
Cardoso, Simão P. | Lopes, Cláudia B. | Pereira, Eduarda | Duarte, Armando C. | Silva, Carlos M.
Competitive Removal of Cd²⁺ and Hg ²⁺ Ions from Water Using Titanosilicate ETS-4: Kinetic Behaviour and Selectivity Полный текст
2013
Cardoso, Simão P. | Lopes, Cláudia B. | Pereira, Eduarda | Duarte, Armando C. | Silva, Carlos M.
Mercury and cadmium are priority hazardous substances. Some titanosilicates have been tested for the removal of Cd²⁺ and Hg²⁺ from single solutions by ion exchange. In this work, the competition between both contaminants for the exchanger binding sites of titanosilicate Engelhard titanosilicate material number 4 (ETS-4) was studied by performing batch experiments with aqueous solutions containing the two counter ions. The results evidenced the large capacity of ETS-4 and shown that the cadmium(II) diffusivity through the sorbent is higher than that of mercury(II). Furthermore, the ETS-4 exhibited higher kinetic and equilibrium selectivities for Cd²⁺, which attained values in the ranges 8.9–12.5 and 7.9–12.8, respectively. With respect to modelling, the pseudo-second-order equation described successfully the competitive removal of Cd²⁺ and Hg²⁺.
Показать больше [+] Меньше [-]Competitive removal of Cd2+ and Hg2+ Ions from water using Titanosilicate ETS-4: kinetic behaviour and selectivity Полный текст
1000
Cardoso, Simão P. | Lopes, Cláudia B. | Pereira, Eduarda | Duarte, Armando C. | Silva, Carlos M.
Mercury and cadmium are priority hazardous substances. Some titanosilicates have been tested for the removal of Cd2+ and Hg2+ from single solutions by ion exchange. In this work, the competition between both contaminants for the exchanger binding sites of titanosilicate Engelhard titanosilicate material number 4 (ETS-4) was studied by performing batch experiments with aqueous solutions containing the two counter ions. The results evidenced the large capacity of ETS-4 and shown that the cadmium(II) diffusivity through the sorbent is higher than that of mercury(II). Furthermore, the ETS-4 exhibited higher kinetic and equilibrium selectivities for Cd2+, which attained values in the ranges 8.9-12.5 and 7.9-12.8, respectively. With respect to modelling, the pseudo-second-order equation described successfully the competitive removal of Cd2+ and Hg2+.
Показать больше [+] Меньше [-]Toxicity of Epoxiconazole to the Marine Diatom Chaetoceros calcitrans: Influence of Growth Conditions and Algal Development Stage Полный текст
2013
Amara, Anis | Quiniou, Franc̦oise | Durand, Gaël | El Bour, Monia | Boudabous, Abdellatif | Hourmant, Annick
Toxicity of Epoxiconazole to the Marine Diatom Chaetoceros calcitrans: Influence of Growth Conditions and Algal Development Stage Полный текст
2013
Amara, Anis | Quiniou, Franc̦oise | Durand, Gaël | El Bour, Monia | Boudabous, Abdellatif | Hourmant, Annick
The triazole fungicide epoxiconazole is extensively used to control fungi on crops and may present some potential risk from runoff on coastal ecosystems located close to agricultural areas. Phytotoxicity assessments were conducted on the marine diatom Chaetoceros calcitrans using both the active ingredient and its formulated product (Opus). The 3-day EC₅₀ using cell count was 2.31 mg/L for epoxiconazole active ingredient and 2.9 μg/L for epoxiconazole-formulated. The fungicide produced an increase of cellular volume, pigment (chlorophylls a, c, and carotenoids) content, ATP synthesis, and rates of photosynthesis and respiration. Progressive algal cell recovery from epoxiconazole effects occurred after 3 days, with the increasing cell density. Differences in cell age, light, and nutrient composition induced changes in epoxiconazole sensitivity. Since these parameters affect cellular division rates, the cellular density is an important parameter in toxicity tests.
Показать больше [+] Меньше [-]Toxicity of Epoxiconazole to the Marine Diatom Chaetoceros calcitrans: Influence of Growth Conditions and Algal Development Stage Полный текст
2013
Amara, Anis | Quiniou, Francoise | Durand, Gael | El Bour, Monia | Boudabous, Abdellatif | Hourmant, Annick
The triazole fungicide epoxiconazole is extensively used to control fungi on crops and may present some potential risk from runoff on coastal ecosystems located close to agricultural areas. Phytotoxicity assessments were conducted on the marine diatom Chaetoceros calcitrans using both the active ingredient and its formulated product (Opus). The 3-day EC50 using cell count was 2.31 mg/L for epoxiconazole active ingredient and 2.9 mu g/L for epoxiconazole-formulated. The fungicide produced an increase of cellular volume, pigment (chlorophylls a, c, and carotenoids) content, ATP synthesis, and rates of photosynthesis and respiration. Progressive algal cell recovery from epoxiconazole effects occurred after 3 days, with the increasing cell density. Differences in cell age, light, and nutrient composition induced changes in epoxiconazole sensitivity. Since these parameters affect cellular division rates, the cellular density is an important parameter in toxicity tests.
Показать больше [+] Меньше [-]First Report of Microcystins and Anatoxin-a Co-occurrence in San Roque Reservoir (Córdoba, Argentina) Полный текст
2013
Ruiz, Márcia | Galanti, Lucas | Ruibal, Ana Laura | Rodríguez P., María Inés | Wunderlin, Daniel Alberto | Amé, María Valeria
First Report of Microcystins and Anatoxin-a Co-occurrence in San Roque Reservoir (Córdoba, Argentina) Полный текст
2013
Ruiz, Márcia | Galanti, Lucas | Ruibal, Ana Laura | Rodríguez P., María Inés | Wunderlin, Daniel Alberto | Amé, María Valeria
The aim of this study was to evaluate the presence of microcystin-LR, microcystin-RR, microcystin-YR, and the neurotoxin anatoxin-a in water samples collected monthly during 1 year in San Roque reservoir (Córdoba, Argentina) to identify the environmental factors that could promote the presence of these cyanotoxins. The HPLC-UV and MS/MS analysis showed the presence of microcystin in most of the sampling times, even when Cyanobacteria were subdominant. Microcystin concentrations varied from not detectable levels to 119.0 μg L⁻¹. Thus, they frequently surpassed the guidelines suggested by WHO for drinking water (1 μg L⁻¹) and recreational exposure (20 μg L⁻¹). To the extent of our knowledge, this is the first report of anatoxin-a in freshwaters in South America. Anatoxin-a concentrations varied from not detectable levels to 6.6 ng L⁻¹, a thousand times below the provisional guideline adopted by New Zealand for drinking water. Microcystin showed significant correlation with Microcystis and Pseudoanabaena while anatoxin-a correlated with Oscillatoria and Anabaena counts. Linear discriminant analysis showed that higher pH levels and more variable chlorophyll-a concentrations were measured in San Roque reservoir when cyanotoxins were present. Lower inorganic nitrogen concentrations were observed in autumn, when the prevalence of Anabaena became significant in Cyanobacteria composition and highest anatoxin-a levels were measured. The observed dynamic of phytoplankton going together with the cyanotoxins occurrence could be explained by the hypothesis of cyanotoxins acting as allelopathic compounds. The microcystin levels measured plus the presence of anatoxin-a show the need of stronger management efforts to preserve human and wildlife health.
Показать больше [+] Меньше [-]First Report of Microcystins and Anatoxin-a Co-occurrence in San Roque Reservoir (Córdoba, Argentina) Полный текст
2013
Ruiz, Marcia | Galanti, Lucas Nicolás | Ruibal, Ana Laura | Rodriguez, Maria Ines | Wunderlin, Daniel Alberto | Amé, María Valeria
The aim of this study was to evaluate the presence of microcystin-LR, microcystin-RR, microcystin-YR, and the neurotoxin anatoxin-a in water samples collected monthly during 1 year in San Roque reservoir (Córdoba, Argentina) to identify the environmental factors that could promote the presence of these cyanotoxins. The HPLC-UV and MS/MS analysis showed the presence of microcystin in most of the sampling times, even when Cyanobacteria were subdominant. Microcystin concentrations varied from not detectable levels to 119.0 μg L−1. Thus, they frequently surpassed the guidelines suggested by WHO for drinking water (1 μg L−1) and recreational exposure (20 μg L−1). To the extent of our knowledge, this is the first report of anatoxin-a in freshwaters in South America. Anatoxin-a concentrations varied from not detectable levels to 6.6 ng L−1, a thousand times below the provisional guideline adopted by New Zealand for drinking water. Microcystin showed significant correlation with Microcystis and Pseudoanabaena while anatoxin-a correlated with Oscillatoria and Anabaena counts. Linear discriminant analysis showed that higher pH levels and more variable chlorophyll-a concentrations were measured in San Roque reservoir when cyanotoxins were present. Lower inorganic nitrogen concentrations were observed in autumn, when the prevalence of Anabaena became significant in Cyanobacteria composition and highest anatoxin-a levels were measured. The observed dynamic of phytoplankton going together with the cyanotoxins occurrence could be explained by the hypothesis of cyanotoxins acting as allelopathic compounds. The microcystin levels measured plus the presence of anatoxin-a show the need of stronger management efforts to preserve human and wildlife health. | Fil: Ruiz, Marcia. Secretaria de Ambiente y Desarr.sustentable de la Nación. Instituto Nacional del Agua y del Ambiente(córdoba); Argentina | Fil: Galanti, Lucas Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina | Fil: Ruibal, Ana Laura. Secretaria de Ambiente y Desarr.sustentable de la Nación. Instituto Nacional del Agua y del Ambiente(córdoba); Argentina | Fil: Rodriguez, Maria Ines. Secretaria de Ambiente y Desarr.sustentable de la Nación. Instituto Nacional del Agua y del Ambiente(córdoba); Argentina | Fil: Wunderlin, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina | Fil: Amé, María Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentina
Показать больше [+] Меньше [-]Perspectives on Chernobyl and Fukushima Health Effects: What Can Be Learned From Eastern European Research? Полный текст
2013
Timothy Mousseau, PhD | Anders Pape Møller, PhD
Assessing Levels of Lead Contamination in Soil and Predicting Pediatric Blood Lead Levels in Tema, Ghana Полный текст
2013
Innocent Joy Kwame Aboh, PhD | Manukure Atiemo Sampson, MPhil | Leticia Abra-Kom Nyaab, MPhil, NEP | Jack Caravanos, DrPH, CIH | Francis Gorman Ofosu, PhD | Harriet Kuranchie-Mensah, MPhil
Background. Tema, Ghana’s main industrial city, has many areas that are suspected to be contaminated by lead. Elevated lead levels can affect, among many other issues, mental development, kidney function and blood chemistry. Children are particularly at risk. Objectives. The objective of this study was to determine the concentration of lead in soil from selected sites in Tema and how these levels relate to local pediatric blood lead predictions. Methods. A total of 47 surface soil samples were taken from 9 different sites. Energy dispersive X-ray technique was employed to determine the levels of lead. Pediatric blood lead levels were estimated using the Integrated Exposure Uptake Bio-Kinetic Model For Lead in Children, developed by the U.S. EPA. Results. The study revealed that the selected sites are highly contaminated by lead. In particular, the concentration of Pb in soil at a used lead acid battery recycling facility exceeded regulatory limits for industrial soil as set by the U.S. EPA. The model for predicting concentrations of lead in the blood of age-specific children showed extremely high probabilities of BLLs exceeding regulatory limits. Conclusions. Based on the results of soil testing, sites that were expected to reveal lead exposure positively demonstrated high levels of contamination, in some areas exceeding U.S. and other national regulatory limits. This information is expected to help authorities make informed clean-up decisions. Competing Interests. The authors declare no competing financial interests.
Показать больше [+] Меньше [-]Exploratory Health Assessment of Chemical Exposures at E-Waste Recycling and Scrapyard Facility in Ghana Полный текст
2013
Jack Caravanos, DrPH, CIH | Edith E. Clarke, DrPH, MPH | Carl S. Osei, MD, MPH | Yaw Amoyaw-Osei
Background. Ghana is one of several West African countries receiving high volumes of used electric and electronic equipment and waste. Within the capital city of Accra, one scrapyard has been the site of extensive e-waste handling, processing and dismantling. Objectives. The Ghana Health Service undertook a study to assess health symptoms and chemical markers of exposure in urine and blood serum. Methods. Eighty-seven e-waste workers and an equivalent control population were enrolled in a study that included: hazard perceptions, reported health symptoms, clinical examinations and urine and blood serum testing. Results. The results indicate that measurable adverse health outcomes are detectable in exposed populations as opposed to unexposed. In addition, statistically significantly elevated levels of the elements barium, manganese, selenium and zinc were present in the urine of e-waste workers as compared to a control group. Similarly, the blood serum levels of barium, cobalt, chromium, copper, iron, selenium and zinc were significantly elevated among those exposed to e-waste recycling. Conclusions. The results indicate that it is likely the Agbogbloshie e-waste proccessing site/scrapyard is exposing workers to hazardous levels of chemical agents. Given the proximity of the residential community, such exposures are likely to affect the local residents as well. Short- and long-term interventions are needed to reduce the chemical health threat to this population. Competing Interests. The authors declare no competing financial interests.
Показать больше [+] Меньше [-]Introduction to “A Critical Look at the Concept of an ‘Effective Dose’ of Radiation” Полный текст
2013
Richard Fuller