Environmental Contamination (environmental + contamination)

Distribution by Scientific Domains


Selected Abstracts


The Impact of Environmental Contamination on Condo Prices: A Hybrid Repeat-Sale/Hedonic Approach

REAL ESTATE ECONOMICS, Issue 1 2006
Bradford Case
We extend the literature on the impact of externalities using an approach based on a hybrid of hedonic and repeat-sales methods. The externality in question is groundwater contamination in Scottsdale, Arizona. The use of condominium sales allows us to assume that major physical characteristics remain unchanged, but location parameters may be altered by urban growth and development as well as contamination. We find an economically significant discount for properties located in the contaminated area. Interestingly, it does not appear until several years after the contamination becomes publicly known, and it seems to have disappeared before the end of the study period. [source]


Subchronic exposure of BALB/c and C57BL/6 strains of Mus musculus to the radioactive environment of the Chornobyl, Ukraine exclusion zone

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001
Brenda E. Rodgers
Abstract Environmental contamination resulting from the Chornobyl, Ukraine, disaster offers a unique opportunity to examine the in vivo biological effects of chronic, low-dose exposure to radiation. Laboratory studies of acute exposure to ionizing radiation have been used to estimate risk and potential human health effects by the extrapolation of laboratory data to situations of low-dose environmental radiation exposure. Few studies, however, have explored the biological consequences of low-dose exposure via in situ environmental radiation in a sentinel species. In the present study, laboratory strains of Mus musculus (BALB/c and 57BL/ 6) were placed in environmental enclosures in the Red Forest region of the Chornobyl exclusion zone. Blood samples were obtained every 10 d, and the micronucleus (MN) test was employed to assess the potential for cytogenetic damage from exposure to Chornobyl radiation. Radionuclide uptake was monitored throughout the study, and dose was estimated for each individual as well as for their offspring. Total dose for the mice experimentally exposed to this environment averaged 1162 mGy for BALB/c (30 d) and 1629 mGy for C57BL/6 (40 d). A higher MN frequency for both strains was observed at day 10, although this change was only statistically significant in the C57BL/6 mice (,23 = 13.41, p = 0.003). Subsequent samples from C57BL/6 resulted in values at or less than the initial frequencies. In BALB/c mice, an increase in MN was also evident at day 30 (,22 = 10.38, p = 0.006). The experimental design employed here allows for the incorporation of traditional laboratory strains, as well as transgenic strains of Mus, as sentinels of environmental radiation contamination. [source]


Environmental Nursing Diagnoses: A Proposal for Further Development of Taxonomy II

INTERNATIONAL JOURNAL OF NURSING TERMINOLOGIES AND CLASSIFICATION, Issue 1 2003
Pauline M. Green PhD
PURPOSE. To propose further development of environmental diagnoses and to offer recommendations for expanding Taxonomy II to include more diagnostic labels that encompass the environmental domain. SOURCES. Literature in the disciplines of nursing, biology, toxicology, public health, sociology, and anthropology. DATA SYNTHESIS. Nurses need language to describe the human responses of individuals, families, communities, and global society to environmental health threats. CONCLUSIONS. New environmental diagnoses will lead to refinement of language that describes the contribution of nursing to an emerging international and community health priority. PRACTICE IMPLICATIONS. Environmental diagnostic labels will allow nurses to name responses and plan interventions that respond to instances or risks of exposure to threats from the physical and sociocultural environment. Search terms: Environmental contamination, environmental health threats, exposure, nursing diagnoses [source]


Bentazon triggers the promotion of oxidative damage in the Portuguese ricefield cyanobacterium Anabaena cylindrica: Response of the antioxidant system

ENVIRONMENTAL TOXICOLOGY, Issue 5 2010
Victor Galhano
Abstract Rice fields are frequently exposed to environmental contamination by herbicides and cyanobacteria, as primary producers of these aquatic ecosystems, are adversely affected. Anabaena cylindrica is a cyanobacterium with a significantly widespread occurrence in Portuguese rice fields. This strain was studied throughout 72 h in laboratory conditions for its stress responses to sublethal concentrations (0.75,2 mM) of bentazon, a selective postemergence herbicide recommended for integrated weed management in rice, with special reference to oxidative stress, role of proline and intracellular antioxidant enzymes in herbicide-induced free radicals detoxification. Activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione S -transferase (GST) increased in a time- and herbicide dose-response manner and were higher than those in the control samples after 72 h. A time- and concentration-dependent increase of malondialdehyde (MDA) levels and the enhanced cell membrane leakage following bentazon exposure are indicative of lipid peroxidation, free radicals formation, and oxidative damage, while increased amounts of SOD, CAT, APX, GST, and proline indicated their involvement in free radical scavenging mechanisms. The appreciable decline in the reduced glutathione (GSH) pool after 72 h at higher bentazon concentrations could be explained by the reduction of the NADPH-dependent glutathione reductase (GR) activity. The obtained results suggested that the alterations of antioxidant systems in A. cylindrica might be useful biomarkers of bentazon exposure. As the toxic mechanism of bentazon is a complex phenomenon, this study also adds relevant findings to explain the oxidative stress pathways of bentazon promoting oxidative stress in cyanobacteria. 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010. [source]


Contaminant-associated alteration of immune function in black-footed albatross (Phoebastria nigripes), a North Pacific predator

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007
Myra E. Finkelstein
Abstract Environmental pollution is ubiquitous and can pose a significant threat to wild populations through declines in fitness and population numbers. To elucidate the impact of marine pollution on a pelagic species, we assessed whether toxic contaminants accumulated in black-footed albatross (Phoebastria nigripes), a wide-ranging North Pacific predator, are correlated with altered physiological function. Blood samples from adult black-footed albatrosses on Midway Atoll, part of the Hawaiian (USA) archipelago, were analyzed for organochlorines (e.g., polychlorinated biphenyls [PCBs] and chlorinated pesticides), trace metals (silver, cadmium, tin, lead, chromium, nickel, copper, zinc, arsenic, selenium, and total mercury), and a sensitive physiological marker, peripheral white blood cell immune function (mitogen-induced lymphocyte proliferation and macrophage phagocytosis). We found a positive significant relationship between organochlorines, which were highly correlated within individual birds (p < 0.001, r > 0.80, Spearman correlation for all comparisons; PCBs, 160 60 ng/ml plasma [mean standard deviation]; DDTs, 140 180 ng/ml plasma; chlordanes, 7.0 3.6 ng/ml plasma; hexachlorobenzene, 2.4 1.5 ng/ml plasma; n = 15) and increased lymphocyte proliferation (p = 0.020) as well as percentage lymphocytes (p = 0.033). Mercury was elevated in black-footed albatrosses (4,500 870 ng/ml whole blood, n = 15), and high mercury levels appeared to be associated (p = 0.017) with impaired macrophage phagocytosis. The associations we documented between multiple contaminant concentrations and immune function in endangered black-footed albatrosses provide some of the first evidence that albatrosses in the North Pacific may be affected by environmental contamination. Our results raise concern regarding detrimental health effects in pelagic predators exposed to persistent marine pollutants. [source]


4-nonylphenol-induced toxicity and apoptosis in Hydra attenuata

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2005
Sophie Pachura
Abstract Effects of 4-nonylphenol (4-NP) onthe morphology and survival of the cnidarian Hydra attenuata were studied under acute exposure conditions. The lethal concentration value inducing 50% mortality after 96 h was 97.5 20 ,g/L, whereas the lethal concentration value inducing 10% mortality after 96 h was 64 25.5 ,g/L. The no-observed-effect concentration based on morphological criteria was less than 25 ,g/L. Hydra was one of the most sensitive freshwater invertebrate species behind the amphipod Hyalella azteca. Toxicity effects appeared rapidly and did not evolve substantially between 24 and 96 h of exposure. Induction of apoptosis was registered during the first hour of exposure to 4-NP at lethal concentrations, indicating rapid effects of the chemical. Abnormal increase of apoptosis may explain the acute toxicity of 4-NP in hydra. Results show that hydra viability is affected in the short term at 4-NP concentrations normally found in contaminated sites, but not at those concentrations reflecting lower levels of environmental contamination. [source]


Human exposure to phthalates via consumer products

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2006
TED SCHETTLER
Summary Phthalate exposures in the general population and in subpopulations are ubiquitous and widely variable. Many consumer products contain specific members of this family of chemicals, including building materials, household furnishings, clothing, cosmetics, pharmaceuticals, nutritional supplements, medical devices, dentures, children's toys, glow sticks, modelling clay, food packaging, automobiles, lubricants, waxes, cleaning materials and insecticides. Consumer products containing phthalates can result in human exposures through direct contact and use, indirectly through leaching into other products, or general environmental contamination. Historically, the diet has been considered the major source of phthalate exposure in the general population, but all sources, pathways, and their relative contributions to human exposures are not well understood. Medical devices containing di-(2-ethylhexyl) phthalate are a source of significant exposure in a susceptible subpopulation of individuals. Cosmetics, personal care products, pharmaceuticals, nutritional supplements, herbal remedies and insecticides, may result in significant but poorly quantified human exposures to dibutyl phthalate, diethyl phthalate, or dimethyl phthalate. Oven baking of polymer clays may cause short-term, high-level inhalation exposures to higher molecular weight phthalates. [source]


Chemical composition and microbial evaluation of Argentinean Corrientes cheese

INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 3 2008
OLGA M VASEK
The chemical and microbial composition of an artisanal cheese made from raw cow's milk produced and consumed in the province of Corrientes (north-eastern Argentina) was evaluated using standard methods. Corrientes cheese has high moisture content (50,60%), normal protein and fat contents (21,27 and 22,26% respectively), and is low in salt (0.5,2.0% w/w). Microbial counts also varied significantly between samples (colony-forming units per gram ranges covering logs of 5,11), probably due to environmental contamination in the raw material. These results will help produce higher quality Corrientes cheeses with well-defined characteristics. [source]


Genotyping of thermotolerant Campylobacter from poultry slaughterhouse by amplified fragment length polymorphism

JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2007
G. Johnsen
Abstract Aim:, To examine the occurrence, diversity and transmission of Campylobacter in a poultry slaughterhouse. Methods and Results:, During a 4-week period, a slaughterhouse was sampled alternately during slaughtering and the following mornings post-disinfection. Samples were taken from poultry at six stages in the slaughter process and from 25 environmental sites. For positive broiler flocks slaughtered on one occasion, 92% and 48% of the environmental sites were positive during slaughter and post-disinfection, respectively. For positive laying hen flocks slaughtered on three occasions, 8,56% and 12,20% of the environmental sites were positive during slaughter and post-disinfection, respectively. Genetic fingerprinting by amplified fragment length polymorphism (AFLP) of the 109 isolates obtained resulted in 28 different AFLP clones. Five AFLP clones were present for more than 1 week. Conclusions:, Slaughtering of Campylobacter -positive broilers resulted in extensive contamination of the slaughterhouse, including the air. A high proportion of the laying hen flocks were Campylobacter positive, but these caused less environmental contamination than the broilers. This, together with the freezing of all layer carcasses, results in a lower public health risk from laying hens, when compared with broilers. Significance and Impact of the Study:, When slaughtering Campylobacter -positive broilers, the implementation of preventive measures is important to reduce contamination of negative carcasses and to protect the workers against infection. [source]


Growth and survival of non-O157:H7 Shiga-toxin-producing Escherichia coli in cow manure

JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007
B. Fremaux
Abstract Aims:, The main objective of this study was to evaluate the behaviour of non-O157:H7 Shiga-toxin-producing Escherichia coli (STEC) strains in cow manure. Methods and Results:, A mixture of eight green-fluorescent-protein-labelled STEC strains was inoculated around 106,107 CFU g,1 into four manure heaps. Two heaps were regularly turned and the two others remained unturned. STEC counts and physical parameters (temperature, pH, moisture content and oxido-reduction potential) were monitored for 1000 manure samples. The highest mean pH values were obtained near the surface at the base of all manure heaps. At the surface, the moisture content decreased from 765% to 42% in turned heaps. Temperatures reached 65C near the main body of all manure heaps, and only 35C near the superficial parts located at the base of them. These two sites (the centre and the base) were associated with D values for the STEC counts of 048 and 239 days, respectively. We were able to detect STEC strains during 42 days in turned manure heaps and during at least 90 days in unturned ones. Conclusions:, These results emphasize the long-term survival of non-O157:H7 STEC in cow manure. Significance and Impact of the Study:, Good management practices (e.g. turning) should be respected in order to minimize the risk of environmental contamination by STEC. [source]


Antioxidant activity of hydrolysates derived from porcine plasma

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2009
Xueming Xu
Abstract BACKGROUND: In China alone, more than 400 million pigs are slaughtered each year to provide meat. Porcine blood is rich in proteins but is usually discarded, which can cause environmental contamination. Recovering porcine blood and converting it to high-value products is therefore economically and environmentally desirable. However, very little information on antioxidant peptides from porcine blood by-products is currently available. In this study the antioxidant properties of porcine plasma hydrolysates PPE and PPA prepared with pepsin and papain respectively were investigated. RESULTS: Both PPE and PPA showed excellent antioxidant activity in a linoleic acid system (AL) compared with ,-tocopherol (VE) at the same concentration (P < 0.01). Their activities were respectively 3.33 and 1.83 times stronger than that of VE at a concentration of 10 g mL,1 and 5.4 and 5.6 times stronger at 100 g mL,1. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (DRSA) reached 48.4 and 43.1% for PPE and PPA respectively at 500 g mL,1. The ferrous ion-chelating power (FICP) of PPE at 100 g mL,1 was about 1.5 times stronger than that of 10 mol L,1 ethylene diamine tetraacetic acid (EDTA) in a 50 mol L,1 Fe2+ system, whereas the FICP of PPA at 100 g mL,1 was 61% that of 10 mol L,1 EDTA. Furthermore, PPE was separated on Resource 15RPC and Superdex peptide 10/300GL columns, and the antioxidant activity of the peptides and its relationship to their polarity and molecular weight (MW) were analysed. The hydrolysate was divided into four groups (R1,R4) with hydrophobicities ranging from weak to strong by Resource 15RPC, while it was divided into three groups (S1, MW 7,12 kDa; S2, MW 3,7 kDa; S3, MW 1,3 kDa) by Superdex peptide 10/300GL. CONCLUSION: The results showed that AL was significantly and positively correlated with the relative amounts of R1, S2 and S3 and that DRSA was dependent on R3 and S1. The fractions of PPE were not responsible for FICP. Copyright 2009 Society of Chemical Industry [source]


Neighborhood Effects and Compensation for Property Value Diminution

LAW & POLICY, Issue 1 2002
Jill J. McCluskey
This paper analyzes the legal issues surrounding defendants' liability for property value diminution caused by stigma from environmental contamination. The courts, law review articles, and public policy analyses are in disagreement over how to handle stigma damages. This paper argues that a reasonable risk of contamination is not required for a nuisance claim if community effects, which were caused by the contamination, are present. The authors then turn to issues regarding the level of damages and propose a methodology for measuring compensation that is based on a guaranteed sales price. This methodology is applied to the RSR smelter in Dallas, Texas. [source]


Persistence of Shiga toxin-producing Escherichia coli O26 in cow slurry

LETTERS IN APPLIED MICROBIOLOGY, Issue 1 2007
B. Fremaux
Abstract Aims: The main objective of this study was to evaluate the growth and survival of Shiga toxin-producing Escherichia coli (STEC) O26 in cow slurry; this serogroup is regarded as an important cause of STEC-associated diseases. Methods and Results: Four STEC were examined by polymerase chain reaction (PCR) to determine whether they harbour key virulence determinants and also by pulsed-field gel electrophoresis (PFGE) to obtain overview fingerprints of their genomes. They were transformed with the pGFPuv plasmid and were separately inoculated at a level of 106 CFU ml,1 in 15 l of cow slurry. All STEC O26 strains could be detected for at least 3 months in cow slurry without any genetic changes. The moisture content of the slurry decreased over time to reach a final value of 75% while the pH increased from 85 to 95 units during the last 50 days. Conclusion: STEC O26 strains were able to survive in cow slurry for an extended period. Significance and Impact of the Study: Long-term storage of waste slurry should be required to reduce the pathogen load and to limit environmental contamination by STEC O26. [source]


Treatment of sanitary-important bacteria by bacteriocin substance V24 in cattle dung water

LETTERS IN APPLIED MICROBIOLOGY, Issue 5 2000
A. Laukov
Quantification of sanitary-important bacteria (e.g. Enterobacteriaceae), as well as indicators of environmental contamination, was assessed in samples of cattle dung from 25 cattle farms in 15 north-eastern Slovakia districts. The inhibitory effect of crude bacteriocin extract CBE V24 from Enterococcus faecalis V24 against Listeria monocytogenes Ohio and Yersinia enterocolitica YE85 was examined in cattle dung water with the aim of finding a new way of eliminating the health risk of the animal slurry. The following bacterial groups were quantified: Salmonella spp., Shigella -like spp., Proteus spp., Enterobacter spp., Citrobacter spp., Pseudomonas spp., Escherichia coli, Listeria spp., staphylococci, streptococci and enterococci (the average count ranged from 102 up to 104 cfu ml,1). Antagonistic effect of the crude bacteriocin from Enterococcus faecalis V24 in the range of 100,600 Arbitrary units per ml (AU ml,1) was shown against the following bacteria: Enterobacter cloacae, Ent. asburiae, Proteus spp., Salmonella spp., Acinetobacter lwoffi, L. monocytogenes as well as Y. enterocolitica YE85. During tests performed to study the inhibitory effect of the crude bacteriocin CBE V24 (concentration 800, 1600 AU ml,1) against L. monocytogenes Ohio and Y. enterocolitica YE85 in experimentally contaminated cattle dung, a reduction of 203 and 144 log cfu ml,1, respectively, was already noted after 1 h after crude bacteriocin CBE V24 addition. [source]


Toward an "omic" physiopathology of reactive chemicals: Thirty years of mass spectrometric study of the protein adducts with endogenous and xenobiotic compounds

MASS SPECTROMETRY REVIEWS, Issue 5 2009
Federico Maria Rubino
Abstract Cancer and degenerative diseases are major causes of morbidity and death, derived from the permanent modification of key biopolymers such as DNA and regulatory proteins by usually smaller, reactive molecules, present in the environment or generated from endogenous and xenobiotic components by the body's own biochemical mechanisms (molecular adducts). In particular, protein adducts with organic electrophiles have been studied for more than 30 [see, e.g., Calleman et al., 1978] years essentially for three purposes: (a) as passive monitors of the mean level of individual exposure to specific chemicals, either endogenously present in the human body or to which the subject is exposed through food or environmental contamination; (b) as quantitative indicators of the mean extent of the individual metabolic processing which converts a non-reactive chemical substance into its toxic products able to damage DNA (en route to cancer induction through genotoxic mechanisms) or key proteins (as in the case of several drugs, pesticides or otherwise biologically active substances); (c) to relate the extent of protein modification to that of biological function impairment (such as enzyme inhibition) finally causing the specific health damage. This review describes the role that contemporary mass spectrometry-based approaches employed in the qualitative and quantitative study of protein,electrophile adducts play in the discovery of the (bio)chemical mechanisms of toxic substances and highlights the future directions of research in this field. A particular emphasis is given to the measurement of often high levels of the protein adducts of several industrial and environmental pollutants in unexposed human populations, a phenomenon which highlights the possibility that a number of small organic molecules are generated in the human organism through minor metabolic processes, the imbalance of which may be the cause of "spontaneous" cases of cancer and of other degenerative diseases of still uncharacterized etiology. With all this in mind, it is foreseen that a holistic description of cellular functions will take advantage of new analytical methods based on time-integrated metabolomic measurements of a new biological compartment, the "adductome," aimed at better understanding integrated organism response to environmental and endogenous stressors. 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:725,784, 2009 [source]


Trichophyton mentagrophytes of rabbit origin causing family incidence of kerion: an environmental study

MYCOSES, Issue 5 2006
P. Van Rooij
Summary Our laboratory was contacted by a family living directly above a rabbit farm. Both their children had developed a kerion, in consequence of a misdiagnosed superficial mycosis. This study was designed to demonstrate a link between the two kerion cases and the environmental contamination. The degree of contamination was estimated and factors favourising the spread of infection were determined. Dermatophytes were isolated from various environmental sites using Rodac plates. For direct sampling of scalp and fur the brushing technique was used. The farm and home environment initially showed a severe contamination by Trichophyton mentagrophytes. At the farm, cages and surfaces covered with rabbit hair were strongly contaminated. As for the home environment, the dog's basket and clothes from the mother carried a large number of spores. Trichophyton mentagrophytes was identified as responsible agent for the children's kerions and the lesions of the rabbits. Mother, eldest child and dog seemed to be excellent carriers. Cleaning and disinfection measures resulted in a reduction of the overall contamination. The home environment was no longer a source of contamination. Nevertheless, on the farm a fair number of dermatophytes could still be isolated from the wire meshes and roof beams covered with fluff. [source]


Metabolomic analysis of host plant resistance to thrips in wild and cultivated tomatoes,

PHYTOCHEMICAL ANALYSIS, Issue 1 2010
Mohammad Mirnezhad
Abstract Introduction , Western flower thrips (Frankliniella occidentalis) are among the most serious crop pests worldwide. Control of thrips mainly depends on pesticides, excessive use of which leads to human health risks and environmental contamination. As an alternative, we study host plant resistance to thrips. Objective , To apply nuclear magnetic resonance spectroscopy (NMR) metabolomics to study host plant resistance to thrips in wild and cultivated tomatoes. Methodology , Ten wild species and 10 cultivated tomato lines were compared. Five replicates of each species and lines were used for a thrips bioassay while another five replicates were used for the metabolomic analysis. The three most resistant and susceptible wild species, and cultivated lines, as identified by the thrips bioassay, were used for the metabolomics, performed by 1H NMR spectroscopy followed by principal component analysis. Results , Wild and cultivated tomatoes differed significantly in thrips resistance. Only wild tomatoes were thrips-resistant, among which Lycopersicon pennellii and L. hirsutum exhibited the lowest thrips damage. Their 1H NMR-based metabolomic profiles were significantly different from those of thrips-susceptible tomatoes. Thrips-resistant tomatoes contained acylsugars, which are known for their negative effect on herbivores. Conclusion , The identification of acylsugars as a resistance factor for thrips in tomato proves that NMR-based metabolomics an important tool to study plant defences, providing fundamental information for the development and realisation of herbivore resistance breeding programmes in agricultural crops. Copyright 2009 John Wiley & Sons, Ltd. [source]


Determination of total urinary mercury by on-line sample microwave digestion followed by flow injection cold vapour inductively coupled plasma mass spectrometry or atomic absorption spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 15 2002
M. Bettinelli
The total mercury content in urine was determined by inductively coupled plasma mass spectrometry with the so-called cold vapour method after on-line oxidative treatment of the sample in a microwave oven (FI-MW-CV-ICPMS). Use of a KBr/KBrO3 mixture, microwave digestion, and the final oxidation with KMnO4, assure the complete recovery of the organic forms of Hg which would be difficult to determine otherwise if using only the CV-ICPMS apparatus. Quantitative recoveries were obtained for phenyl Hg chloride (PMC), dimethyl Hg (DMM), Hg acetate (MA) and methyl Hg chloride (MMC). Use of automatic flow injection microwave systems (FI-MW) for sample treatment reduces environmental contamination and allows detection limits suitable for the determination of reference values. Since no certified reference materials were commercially available in the concentration ranges of interest, the accuracy of the proposed procedure has been assessed by analysing a series of urine samples with two independent techniques, ICP-MS and AAS. When using the FI-MW-CV-ICP-MS technique, the detection limit was assessed at 0.03g/L Hg, while with FI-MW-CV-AAS it was 0.2g/L Hg. The precision of the method was less than 2,3% for FI-MW-CV-ICP-MS and about 3,5% for FI-MV-CV-AAS at concentrations below 1g/L Hg. These results show that ICP-MS can be considered as a "reference technique" for the determination of total urinary Hg at very low concentrations, such as are present in non-exposed subjects. Copyright 2002 John Wiley & Sons, Ltd. [source]


Assessment of organochlorine pesticides and metals in ring-tailed lemurs (Lemur catta) at Beza Mahafaly Special Reserve, Madagascar

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 12 2009
Thomas R. Rainwater
Abstract Like most of Madagascar's endemic primates, ring-tailed lemurs (Lemur catta) face a number of threats to their survival. Although habitat loss is of greatest concern, other anthropogenic factors including environmental contamination may also affect lemur health and survival. In this study, we examined ring-tailed lemurs from the Beza Mahafaly Special Reserve (BMSR), southern Madagascar for exposure to organochlorine (OC) pesticides and metals and examined differences in contaminant concentrations between sexes and among age groups, troops, and habitats. A total of 14 pesticides and 13 metals was detected in lemur blood (24 individuals) and hair (65 individuals) samples, respectively. p,p,-DDT, heptachlor, aldrin, heptachlor epoxide, endrin aldehyde, and endrin were among the most prevalent pesticides detected. Surprisingly, the persistent metabolite of p,p,-DDT, p,p,-DDE, was not detected. The most commonly detected metals were aluminum, zinc, boron, phosphorus, silicon, and copper, whereas metals considered more hazardous to wildlife (e.g. arsenic, cadmium, lead, selenium, vanadium) were not found above detection limits. Overall, concentrations of OC pesticides and metals were low and similar to those considered to be background concentrations in other studies examining the ecotoxicology of wild mammals. Few inter-sex, -age, -troop, and -habitat differences in contaminant concentrations were observed, suggesting a uniform distribution of contaminants within the reserve. Several statistically significant relationships between lemur body size and contaminant concentrations were observed, but owing to the lack of supportive data regarding contaminant exposure in wild primates, the biological significance of these findings remains uncertain. Results of this study document exposure of ring-tailed lemurs at BMSR to multiple OC pesticides and metals and provide essential baseline data for future health and toxicological evaluations of lemurs and other wild primates, especially those in regions with expanding agricultural and mining operations. Am. J. Primatol. 71:998,1010, 2009. 2009 Wiley-Liss, Inc. [source]


Temporal patterns and quantification of excretion of Mycobacterium avium subsp paratuberculosis in sheep with Johne's disease

AUSTRALIAN VETERINARY JOURNAL, Issue 1 2000
RJ WHITTINGTON
Objectives To determine the frequency of excretion of Mycobacterium avium subsp paratuberculosis in Merino sheep with Johne's disease and to quantify excretion in a group of Merino sheep. Design A pen and laboratory experiment Procedure Seven sheep selected from an affected flock on the basis of acid-fast bacilli in the sheep's faeces were housed and total daily faecal output was collected, weighed and subjected to culture for M avium subsp paratuberculosis. An end-point titration method was used to enumerate viable M avium subsp paratuberculosis in a 15 day pooled sample from five sheep that had acid-fast bacilli in their faeces while housed. Results Four sheep with subclinical multibacillary Johne's disease excreted M avium subsp paratuberculosis each day for 11 days of cultural observation. A further three sheep were intermittent excreters but lacked other evidence of infection with M avium subsp paratuberculosis. The average number of viable bacteria excreted was 1.09 108 per gram of faeces while total daily excretion was 8.36 1010 viable M avium subsp paratuberculosis per sheep. Examination of faecal smears stained with Ziehl Neelsen was an unreliable means of assessing daily excretion in individual animals except in those with severe lesions. Conclusion Excretion of M avium subsp paratuberculosis in Merino sheep with multibacillary Johne's disease occurred daily, proving that environmental contamination can be continuous on farms with endemic ovine Johne's disease. Faecal culture is a useful method for detecting infection as it does not appear to be affected by the timing of collection of a sample from sheep with multibacillary disease however, to maximise the sensitivity of disease surveillance using faecal culture, sampling rates should be adjusted to take account of the proportions of multibacillary and paucibacillary cases. [source]


Peritonitis due to the dermatiaceous mold Exophiala dermatitidis complicating continuous ambulatory peritoneal dialysis

CLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2003
J. Greig
Exophiala (Wangiella) dermatitidis is a dermatiaceous mold that is an occasional cause of infection in the immunocompromised. We report a case of continuous ambulatory peritoneal dialysis-associated peritonitis probably due to environmental contamination with this organism. Prompt catheter removal and aggressive treatment with amphotericin B allowed an eventual return to peritoneal dialysis. [source]