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Results 201 - 250 of 594
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Claudel Thierry - - 2007
Many aspects of physiology and behavior in organisms from bacteria to man are subjected to circadian regulation. Indeed, the major function of the circadian clock consists in the adaptation of physiology to daily environmental change and the accompanying stresses such as exposition to UV-light and food-contained toxic compounds. In this ...
Caumette Guilhem - - 2007
Trace elements often accumulate in keratin-rich tissues. Hair, nails, and horns grow steadily but once formed are metabolically inactive and provide an archive of trace element exposure when analyzed in segments. Here we demonstrate the use of laser ablation ICP-MS for the high-resolution monitoring of trace elements in the horns ...
Singh Nrashant - - 2007
Arsenic is a major environmental pollutant and exposure occurs through environmental, occupational and medicinal sources. The contaminated drinking water is the main source of exposure and affected countries are India (West Bengal), Bangladesh, China, Taiwan, Thailand, Chile, Argentina and Romania. Concentrations of arsenic in affected areas are several times higher ...
Buschmann Johanna - - 2007
Arsenic contamination of groundwater has been identified in Cambodia, where some 100,000 family-based wells are used for drinking water needs. We conducted a comprehensive groundwater survey in the Mekong River floodplain, comprising an area of 3700 km(2) (131 samples, 30 parameters). Seasonal fluctuations were also studied. Arsenic ranged from 1 ...
Soucek David J - - 2007
I tested the hypothesis that if sodium sulfate alters the bioenergetics of Ceriodaphnia dubia, concentrations that cause reduced fecundity in the short (7-day) and long (5 generations) term should also cause changes in feeding rate and/or metabolism, measured as oxygen consumption. In addition, to test the hypothesis that an altered ...
Maduabuchi J-M U - - 2007
Numerous studies have described environmental exposure of humans to heavy metals in African populations. Little is known about the exposure to heavy metal toxins from processed or unprocessed foods consumed in Africa, and no data exists on the food concentrations of arsenic and chromium, which are potential carcinogens and systemic ...
Ning Zhixiong - - 2007
In the Ba Men region of Inner Mongolia, China, a high prevalence of chronic arsenism has been reported in earlier studies. A survey of the arsenic contamination among wells from groundwater was conducted to better understand the occurrence of arsenic (As) in drinking water. A total of 14,866 wells (30% ...
Pedroso Mariana S - - 2007
Acute silver effects on whole-body ion regulation and Na(+),K(+)-ATPase activity were evaluated in the euryhaline copepod Acartia tonsa. Experiments were run at 20 degrees C, three different salinities (5, 15 and 30 ppt), in either the absence or the presence of food (diatom Thalassiosira weissflogii; 2 x 10(4)cells/mL). Standard static-renewal ...
Kile Molly L - - 2007
Millions of people in Bangladesh are at risk of chronic arsenic toxicity from drinking contaminated groundwater, but little is known about diet as an additional source of As exposure. We employed a duplicate diet survey to quantify daily As intake in 47 women residing in Pabna, Bangladesh. All samples were ...
Fiorentino Carmen E - - 2007
Changes in the quality of groundwater resources are related to the presence and concentration of contaminants, especially trace elements such as arsenic, boron, fluoride and vanadium. Vanadium is a rare element naturally abundant, generally found in combination with other elements. Vanadium pentoxide is known to have aneugenic effects. Thus, a ...
Starkov Vladislav G - - 2007
The existing data indicate that snake venom is most toxic towards the natural vertebrate preys. Several species of snake include arthropods in their food. However, there is no available data on the toxicity of venom from entomophagous snakes towards their prey. We have studied the toxicity of venom from vipers ...
Ostergren A - - 2007
The food contaminant norharman structurally resembles MPTP a compound that selectively damages pigmented brain areas. Both compounds are sequestered and retained in melanin-containing neurons. The aim of the study was to examine whether intracellular melanin can modulate the toxicity of norharman in melanin-loaded PC12 cells. Dopamine melanin protected against norharman-induced ...
Per Hüseyin - - 2007
The fast ripening of fruits means they may contain various harmful properties. A commonly used agent in the ripening process is calcium carbide, a material most commonly used for welding purposes. Calcium carbide treatment of food is extremely hazardous because it contains traces of arsenic and phosphorous. Once dissolved in ...
Rose Martin - - 2007
This study has measured the content of total and inorganic forms of arsenic in seaweed available on retail sale for consumption, to provide data for dietary exposure estimates and to support advice to consumers. A total of 31 samples covering five varieties of seaweed were collected from various retail outlets ...
Amster Eric - - 2007
Medicinal use of dietary herbal supplements can cause inadvertent arsenic toxicosis. A 54-year-old woman was referred to the University of California, Davis, Occupational Medicine Clinic with a 2-year history of worsening alopecia and memory loss. She also reported having a rash, increasing fatigue, nausea, and vomiting, disabling her to the ...
Lance Emilie - - 2007
Hepatotoxins are frequently produced by many cyanobacterial species. Microcystins (MCs) are the most frequent and widely studied hepatotoxins, with potentially hazardous repercussions on aquatic organisms. As a ubiquitous herbivore living in eutrophic freshwaters, the snail Lymnaea stagnalis (Gastropoda: Pulmonata) is particularly exposed to cyanobacteria. The toxic filamentous Planktothrix agardhii is ...
Key Peter - - 2007
This study examined the toxicity of three pesticides, singly and in mixture, to grass shrimp (Palaemonetes pugio) larvae. The pesticides included atrazine, an herbicide used on turf grass and field crops; fipronil, a persistent insecticide used against termites and fire ants; and imidacloprid, a systemic insecticide used in agricultural and ...
Rathinasabapathi Bala - - 2007
Brake fern, Pteris vittata, not only tolerates arsenic but also hyperaccumulates it in the frond. The hypothesis that arsenic hyperaccumulation in this fern could function as a defense against insect herbivory was tested. Fronds from control and arsenic-treated ferns were presented to nymphs of the grasshopper Schistocerca americana. Feeding damage ...
Jones F T - - 2007
In the mind of the general public, the words "arsenic" and "poison" have become almost synonymous. Yet, As is a natural metallic element found in low concentrations in virtually every part of the environment, including foods. Mining and smelting activities are closely associated with As, and the largest occurrence of ...
Anetor John I - - 2007
Arsenic (As) is a ubiquitous metalloid found in several forms in food and the environment, such as the soil, air and water. The predominant form is inorganic arsenic in drinking water, which is both highly toxic and carcinogenic and rapidly bioavailable. As is currently one of the most important environmental ...
Izawa Hiromi - - 2007
The toxicity of endocrine disrupters is involved in the activation of the aryl hydrocarbon receptor (AhR). We examined the toxicity of diesel exhaust particles (DEPs) using the Ah immunoassay (Ah-I) to study the inhibitory effects of various foods and polyphenols on DEP-induced AhR activation. The toxicity equivalent of DEP was ...
Brima Eid I - - 2007
Millions of people in some of the poorest regions of the world are exposed to high levels of arsenic through drinking contaminated water. It has been reported that development of cancer caused by arsenic exposure in such populations is dependent on dietary and nutritional factors which can modulate arsenic metabolism. ...
Pereira Joana Luísa - - 2007
The widespread increase of pesticides application in crops frequently leads to the contamination of vicinal freshwater lentic ecosystems. Herbicides such as propanil may impair cladoceran fitness, which is per se strongly influenced by the food availability and/or its acquisition efficiency. This work intended to evaluate the responses of Daphnia magna ...
Borak Jonathan - - 2007
Concerns about the adverse effects of chronic arsenic exposure have focused on contaminated drinking water and airborne workplace exposures; the risks of naturally occurring arsenic in foods have received less attention. About 90% of the arsenic in US diets comes from seafood, of which only a small proportion occurs in ...
Pieters Barry J - - 2006
Recent studies showed that limiting food conditions resulted in either increased or decreased sensitivity of Daphnia magna to toxicants. It remained unclear whether these contrasting food-dependent alterations in toxicity resulted from differences in intrinsic sensitivity of the daphnids or from changes in toxicokinetics and resource allocation. It is hypothesized here ...
Sancha Ana María - - 2006
Coagulation technology has been used since 1970 in northern Chile for removing arsenic from drinking-water. This experience suggests that coagulation is an effective technology for the removal of arsenic. It is currently possible to reduce arsenic from 400 microg/L to 10 microg/L at a rate of 500 L/sec, assuming pH, ...
Huq S M Imamul - - 2006
Arsenic contamination in groundwater in Bangladesh has become an additional concern vis-à-vis its use for irrigation purposes. Even if arsenic-safe drinking-water is assured, the question of irrigating soils with arsenic-laden groundwater will continue for years to come. Immediate attention should be given to assess the possibility of accumulating arsenic in ...
Valenti Theodore W - - 2006
Chlorine (Cl) is a highly toxic, widely used halogen disinfectant that is present in point-source pollution discharges from wastewater treatment plants and industrial facilities. The U.S. Environmental Protection Agency freshwater criteria for Cl are 19 microg total residual Cl (TRC)/L as a maximum 1-h average concentration and 11 microg TRC/L ...
Searcy Dennis G - - 2006
Although sulfide is typically regarded as toxic to eukaryotic cells, it is avidly consumed by Tetrahymena pyriformis. That was observed only when the sulfide concentration was kept below 1 microM. Previously concentrations that were too high had been tested. A new device (Sulfidostat) was used to measure sulfide consumption in ...
Williams P N - - 2006
Concern has been raised by Bangladeshi and international scientists about elevated levels of arsenic in Bengali food, particularly in rice grain. This is the first inclusive food market-basket survey from Bangladesh, which addresses the speciation and concentration of arsenic in rice, vegetables, pulses, and spices. Three hundred thirty aman and ...
Shibata Tomoyuki - - 2006
Mulch made from recycled construction and demolition (C&D) wood has been reported to contain elevated levels of arsenic from inadvertent inclusion of chromated copper arsenate (CCA)-treated wood. Such mulch is also commonly colored with iron oxide, a compound known to bind arsenic. The objectives of this study were to quantify ...
Ahamed Sad - - 2006
This communication presents results of our 2-year survey on groundwater arsenic contamination in three districts Ballia, Varanasi and Gazipur of Uttar Pradesh (UP) in the upper and middle Ganga plain, India. Analyses of 4,780 tubewell water samples revealed that arsenic concentrations in 46.5% exceeded 10 microg/L, in 26.7%, 50 microg/L ...
Oh Su Jin - - 2006
Aquatic toxicities of six benzimidazole-based anthelmintics-namely, albendazole, thiabendazole, flubendazole, febantel, fenbendazole, and oxfendazole-were evaluated with a marine bacterium, Vibrio fischeri, and a freshwater invertebrate, Daphnia magna. Delayed and chronic toxicity tests using D. magna also were conducted for benzimidazoles with high acute toxicity. Vibrio fischeri was greater than 10-fold less ...
Smith Nicole M - - 2006
Many Bangladeshi suffer from arsenic-related health concerns. Most mitigation activities focus on identifying contaminated wells and reducing the amount of arsenic ingested from well water. Food as a source of arsenic exposure has been recently documented. The objectives of this study were to measure the main types of arsenic in ...
Lance Emilie - - 2006
The last two decades have been marked by an increasing occurrence of toxic cyanobacterial blooms in aquatic ecosystems. These pose an expanding threat to the environment and to human health. Among the intracellular toxins produced by cyanobacteria, microcystins (hepatotoxins) are the most frequent and widely studied. As an ubiquitous herbivore ...
Almela Concepción - - 2006
Total arsenic, inorganic arsenic, lead and cadmium contents were determined in 112 samples of seaweed preparations sold in Spain (seaweed packed in plastic or cardboard box, seaweed in the form of tablets and concentrates, foods containing seaweed, and canned seaweed). The concentration ranges found, expressed in mg/kg, dry weight, were: ...
Chung Jinwook - - 2007
We tested the hypothesis that the H(2)-based membrane biofilm reactor (MBfR) is capable of reducing multiple oxidized contaminants, a common situation for groundwater contamination. We conducted bench-scale experiments with three groundwater samples collected from California's San Joaquin Valley and on two synthetic groundwaters containing selenate and chromate. The actual groundwater ...
Kolts Jason M - - 2006
Food is added to exposure solutions in cladoceran chronic toxicity tests and sometimes in acute toxicity tests, but its effects on the bioavailability of toxicants have not been studied extensively. We compared the toxicity of waterborne Ag and Cu to Ceriodaphnia dubia in the presence or absence of food (a ...
Ward Timothy J - - 2006
Tests were conducted with mysids (Americamysis bahia) and silversides (Menidia beryllina) to evaluate the influence of salinity and organic carbon on the chronic toxicity of silver. During 7- and 28-d tests conducted at 10, 20, and 30% per hundred salinity, higher concentrations of dissolved silver generally were required to cause ...
Zhu Yong-Guan - - 2006
Arsenic accumulation in cereal crops represents an important pathway for human exposure to arsenic from the environment. The objectives of the present work were to find whether the relationship between arsenate and phosphate (Pi) uptake rate differs among genotypes and to select genotypes with a low arsenate uptake rate with ...
Tillman P Glynn - - 2006
Susceptibility of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), and its endoparasitoid Trichopoda pennipes (F.) (Diptera: Tachinidae) to acetamiprid, cyfluthrin, dicrotophos, indoxacarb, oxamyl, and thiamethoxam was compared in residual and oral toxicity tests. In the residual toxicity test, cyfluthrin, dicrotophos, and oxamyl were highly toxic to N. ...
Osaki Kae - - 2006
To investigate the environmental safety of waste disposal landfill sites and of land reclaimed from such sites, we evaluated the toxicity of leachate from these sites by a combination of bioassays in the Japanese killifish medaka Oryzias latipes. We tested for lethal toxicity in adult and larval medaka and for ...
Ferreccio Catterina - - 2006
The problem of arsenic in Chile was reviewed. In Chile, the population is exposed to arsenic naturally via drinking-water and by air pollution resulted from mining activities. The sources of arsenic were identified to estimate the exposure of population to arsenic through air, water, and food. Health effects, particularly early ...
Yang Weichun - - 2006
Synthetic pyrethroids are widely used insecticides in both agricultural and urban environments. Recent studies show frequent appearances of pyrethroid residues in runoff effluents and sediments, which stimulated concerns over the potential ecotoxicological implications. Pyrethroids are known to have two contrasting characteristics, high aquatic toxicity and strong affinity for the solid ...
Meliker Jaymie R - - 2006
Accurate estimates of inorganic arsenic intake are critical for evaluating potential health risks. Intake estimates have not been critically examined in regions of the United States where people are at risk from arsenic concentrations in drinking water exceeding the maximum contaminant limit of 10 microg/l. In southeastern Michigan, approximately 8% ...
Chaurand Perrine - - 2007
Basic oxygen furnace (BOF) steel slag is a residue from the basic oxygen converter in steel-making operations, and is partially reused as an aggregate for road constructions. Although BOF slag is an attractive building material, its long-term behaviour and the associated environmental impacts must be taken into account. Indeed BOF ...
Peña-Vázquez Elena - - 2006
The behaviour of arsenic and antimony in the Ría de Arousa (Galicia, north west of Spain) and the influence of the Prestige accident in the estuary is evaluated. As and Sb were simultaneously determined by HG-ICPOES in seawater samples after a preconcentration with La in a knotted reactor. The highest ...
Bohrer Denise - - 2006
Pharmacopoeias prescribe tests to determine the levels of arsenic in raw materials and glass containers. In this study, glass ampoules for injectables containing individually the main components of intravenous nutrition formulations were submitted to the hydrolytic resistance test by heating at 121 degrees C for 30 min. As(V) and As(III) ...
Staudigel Hubert - - 2006
Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu'u seamount. Nafanua grew from the 1,000-m-deep crater floor in <4 years and could reach the sea surface within decades. Vents fill Vailulu'u crater with a thick suspension of particulates and ...
Hsiung Tung-Ming - - 2006
An off-line process-based speciation technique was devised here to quantitatively determine toxic inorganic arsenic (iAs), methylarsonic acid (MA), dimethylarsinic acid (DMA), and the dominant, albeit virtually nontoxic, arsenobetaine (AB) in Pacific oysters (Crassostrea gigas). Oysters were extracted with fresh methanol-water (8+2), and this was replicated three times. They were then ...
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