Open Access. Powered by Scholars. Published by Universities.®

Toxicology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 211 - 240 of 266

Full-Text Articles in Toxicology

Stochastic Intra-Cellular Modeling, Thomas E. Hopkins Mar 2003

Stochastic Intra-Cellular Modeling, Thomas E. Hopkins

Theses and Dissertations

Air Force personnel may sometimes come into contact with potentially harmful chemicals while performing their duties. Of course the Air Force desires to keep any potential health risks to its members to a minimum. To this end the Air Force would like to identify which chemicals are toxic, their level of toxicity, and the processes by which these chemicals disrupt normal biological activities at the cellular level. The development of mathematical models can be of great benefit to toxicity studies. Because real world systems involve randomness, that is noise, and the desire is to create mathematical models to represent those …


Analysis Of Phycotoxin And Mycotoxin, Contaminants In Foods, Using Liquid Chromatography - Mass Spectrometry Techniques, Ana Brana Magdalena Jan 2003

Analysis Of Phycotoxin And Mycotoxin, Contaminants In Foods, Using Liquid Chromatography - Mass Spectrometry Techniques, Ana Brana Magdalena

Theses

The impact of phycotoxins and mycotoxins on human and animal health are of important concern for worldwide authorities and the scientific community. Liquid chromatography-mass spectrometry (LC-MS) techniques have been developed, optimised and validated for the analysis of these toxins.

Phycotoxins are potentially toxic substances, which are produced by marine phytoplankton and which may accumulate in shellfish or finfish. Azaspiracid poisoning (AZP) is a recently discovered syndrome that has been implicated in several incidents of human intoxications. A study was undertaken to examine the distribution of azaspiracids (AZA) in scallops {Pecten maximiis) and mussels {Mytiliis edulis). Domoic acid (DA) is an …


Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall Jan 2003

Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall

Biological Sciences Faculty Publications

The importance of distinguishing toxic and non-toxic algal species is becoming a more common problem for management decisions associated with various freshwater and estuarine habitats. An example is given where two dinoflagellates, originally unidentified as closely resembling the toxin producing Pfiesteria spp., have been compared to these species. In order to clarify any relationship to Pfiesteria spp., scanning electron microscopy was used to determine the plate tabulation patterns of these dinoflagellates and make comparisons to the tabulation present in Pfiesteria spp. The results indicated significant differences in the plate tabulations of these taxa to distinguish them from Pfiesteria …


Optimization Of Edxrf For The Study Of Heavy Metal Pollution Of Lake Victoria, Nk Mahommed, In Makundi Nov 2002

Optimization Of Edxrf For The Study Of Heavy Metal Pollution Of Lake Victoria, Nk Mahommed, In Makundi

Tanzania Journal of Science

This study reports on the optimisation and calibration of the Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer installed in the Department of Physics, University of Dar es Salaam. The spectrometer was subsequently utilized to determine concentrations of heavy metals in water hyacinth (Eichhornia crassipes (Mart) Solms.) found growing along the shore of Lake Victoria. The optimal conditions and detection limits were determined experimentally by variation of the excitation parameters. The study found that the use of a collimator with two apertures of diameter 4 mm each placed 8 mm apart and made of materials that do not interfere with elements to …


1080 Summary Information, Department Of Agriculture, Western Australia, Department Of Conservation And Land Management, Western Australia, Department Of Health, Western Australia May 2002

1080 Summary Information, Department Of Agriculture, Western Australia, Department Of Conservation And Land Management, Western Australia, Department Of Health, Western Australia

Biosecurity research reports

Fluoroacetate, the active ingredient of 1080, occurs naturally in toxic plants in Australia, South Africa, and South America. Manufactured I080 underpins most vertebrate pest control programs in Australia and New Zealand. Fluoroacetate occurs naturally in about 40 plant species in Australia with most of these plants restricted to the south-west of WA.

I080 was introduced to rabbit control programs in the early 1950s and therefore has a long history of proven effectiveness and safety in Australia. There have been few repo1ted problems associated with human safety, environmental persistence, bioaccumulation or impact on populations of non-target species.

In particular, I080 baits …


Assessment Of Heavy Metal Pollution In The Lupa Gold Field, Sw Tanzania, S. R. Mnali Dec 2001

Assessment Of Heavy Metal Pollution In The Lupa Gold Field, Sw Tanzania, S. R. Mnali

Tanzania Journal of Science

The concentrations of AS, Cd, Cr, Cu, Hg and Pb were determined in water, stream sediments, soil, and mine tailings from Lupa Gold Field (LGF), SW Tanzania, in order to assess their pollution levels. As, Cd and Cr were determined by automated Graphite Furnace Absorption Spectrophotometry. Cu and Pb were analysed by Air-Acetylene Flame, while Hg was analysed by Cold Vapour Atomic Absorption Spectrophotometry. The mean concentrations obtained were: As: 0.44 ppb (water), 1.2 ppm (sediments), 0.44 ppm (soil) and 5.2 ppm (tailings); Cd: 0.03 ppb (water), 0.03 ppm (sediments), 0.03 ppm (soil) and 0.50 ppm (tailings); Cr: 1.4 ppb …


The Standardized Fish Bioassay Procedure For Detecting And Culturing Actively Toxic Pfiesteria, Used By Two Reference Laboratories For Atlantic And Gulf Coast States, Joann M. Burkholder, Harold G. Marshall, David W. Seaborn, Nora J. Deamer-Melia Oct 2001

The Standardized Fish Bioassay Procedure For Detecting And Culturing Actively Toxic Pfiesteria, Used By Two Reference Laboratories For Atlantic And Gulf Coast States, Joann M. Burkholder, Harold G. Marshall, David W. Seaborn, Nora J. Deamer-Melia

Biological Sciences Faculty Publications

In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the "gold standard" that must be used to detect toxic strains of Pfiesteria slop. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in …


Heavy Metals And Organic Pollutants In Sediments Of Dar Es Salaam Harbour Prior To Dredging In 1999, J F Machiwa Dec 2000

Heavy Metals And Organic Pollutants In Sediments Of Dar Es Salaam Harbour Prior To Dredging In 1999, J F Machiwa

Tanzania Journal of Science

Heavy metals and organic contaminants were analysed in the sediments of the inner area of the Dar es Salaam harbour. Complementary analytical parameters, such as, the organic carbon content and the silt/clay fraction of the sediments showed good positive correlation (r = 0.64). Stations that had high content of fine grain material in the sediment also indicated relatively high level of organic carbon and pollutants. The Florida criteria (MacDonald 1993) for assessment of pollution of tropical marine sediments was adopted in oredr to evaluate the extent of pollution in Dar es Salaam harbour sediments. The Florida criteria is one of …


New Polyether Toxins From Shellfish And Marine Phytoplankton: Isolation Studies And Development Of Analytical Methods, Alan G. Bishop Jan 1999

New Polyether Toxins From Shellfish And Marine Phytoplankton: Isolation Studies And Development Of Analytical Methods, Alan G. Bishop

Theses

There are three classes of polyether toxins responsible for Diarrhetic Shellfish Poisoning (DSP) world-wide. The causative toxins are okadaic acid (OA) and derivatives (DTXs), pectenotoxins (PTXs) and yessotoxins (YTXs). The origin of these toxins are phytoplankton from Dinophysis or Prorocentrum spp. OA has been demonstrated for most outbreaks in Europe and more recently a new isomer DTX-2 has been reported in Ireland.

Marine phytoplankton biomass samples consisting predominantly of Dinophysis acuta, were acquired using a large double plankton net from waters off the South-west coast of Ireland. Analysis of unialgal samples using high performance liquid chromatography (HPLC) with fluorescence and …


Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt Jan 1998

Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt

Civil & Environmental Engineering Faculty Publications

The toxicity of common compounds of lead, cadmium and zinc was evaluated in waters similar to that found in the world's largest lead producing area in Missouri. Static, acute toxicity tests were performed using fathead minnows (Pimephales promelas) and water fleas (Daphnia magna) respectively. Test organisms were subjected to varying amounts of sulfide, carbonate, chloride and sulfate salts of lead, zinc and cadmium mixed in hard, alkaline waters typical to this region. Median lethal concentrations were calculated using nominal versus measured metal concentrations. Measured metal concentrations included four different metal fractionation (extraction/filtration) techniques at different pH …


1080 Operational Procedures Manual - Second Edition, Agriculture Western Australia Jan 1998

1080 Operational Procedures Manual - Second Edition, Agriculture Western Australia

Biosecurity published reports

Sodium fluoroacetate (1080) is an extremely toxic substance which can be a danger to humans if handled incorrectly. At the same time 1080 is the most effective and efficient poison for the control of Western Australia's main vertebrate pest species including rabbits, wild dogs and foxes. One of the main reasons for its usefulness in Western Australia is that many native animals have a high tolerance to it and so may not be affected by baiting.

Industry Resource Protection Program (IRPP) This program, part of Agriculture Western Australia, supports feral animal control carried out by its staff and community groups. …


Ecological Water Treatment System For Removal Of Phosphorus And Nitrogen From Polluted Water, Ray W. Drenner, Donald J. Day, Stacy J. Basham, J. Durward Smith, Susan I. Jensen Jan 1997

Ecological Water Treatment System For Removal Of Phosphorus And Nitrogen From Polluted Water, Ray W. Drenner, Donald J. Day, Stacy J. Basham, J. Durward Smith, Susan I. Jensen

School of Natural Resources: Faculty Publications

We propose that phosphorus and nitrogen can be removed from polluted water using an ecological water treatment system consisting of periphyton and fish. In the proposed system, polluted water flows through a series of vessels, and the nutrients are taken up by periphyton growing on porous screens. Algal-grazing fish feed on the periphyton and either assimilate or egest the nutrients in mucus-bound feces that settle from the water into a sediment trap. Both the fish and their feces can be harvested as nutrient sinks. In this study we examined the effects of an algal-grazing cichlid (Tilapia mossambica) and …


Comparison Of Positive Screening And Confimatory Results From Federally Mandated Drug Testing Of Urine, Mary M. Stuck Jul 1996

Comparison Of Positive Screening And Confimatory Results From Federally Mandated Drug Testing Of Urine, Mary M. Stuck

Community & Environmental Health Theses & Dissertations

The purpose of this study was to analyze the accuracy of FDA approved immunoassays for the detection of drug positive urine samples.

Federal civilian employees are tested under the strict protocol of the Department of Health and Human Services mandatory guidelines for federal workplace drug testing programs. The guidelines provide for a two instrument testing protocol for the analysis of urine samples. The first is an FDA approved immunoassay. Samples which test positive on this screening immunoassay are then submitted for confirmatory testing with the "gold standard" gas chromatography/mass spectrometry.

Agency monthly drug testing summaries, required under the DHHS guidelines …


Acidic Marine Biotoxins Implicated In Diarrhetic Shellfish Poisoning, Eoin P. Carmody Jan 1996

Acidic Marine Biotoxins Implicated In Diarrhetic Shellfish Poisoning, Eoin P. Carmody

Theses

An okadaic acid (OA) etiology has been demonstrated for most outbreaks of diarrhetic shellfish poisoning (DSP) in Europe, An isomer of OA, dinophysistoxin-2 (DTX-2), has recently been found in Irish waters and, in 1991 and 1994, was the major toxin during prolonged infestations in cultivated mussels (Mytilus edulis) along the south-west coast of Ireland.

The OA class of DSP toxins have been analysed by HPLC using modified versions of three established fluorescent derivatisation methods. A ‘dual tag’ method for the confirmation of specific toxins has also been developed.

Survey work has been carried out over the past four years on …


Fish Tissue Contamination In Maine Lakes : Data Report, Jeanne Difranco, Linda Bacon, Barry Mower, David Courtemanch Sep 1995

Fish Tissue Contamination In Maine Lakes : Data Report, Jeanne Difranco, Linda Bacon, Barry Mower, David Courtemanch

Maine Collection

Fish Tissue Contamination in Maine Lakes : Data Report

by Jeanne DiFranco, Linda Bacon, Barry Mower and David Courtemanch

Regional Environmental Monitoring and Assessment Program (REMAP)

State of Maine Department of Environmental Protection, Bureau of Land and Water Quality, Division of Environmental Assessment, State House Station 17, Augusta, Maine 04333 (September 1995).

Contents: List of Figures and Tables / I. Introduction / II. Goals and Objectives / III. Experimental Design / IV. Methods / V. Data / VI. Quality Assurance-Quality Control / Appendices A-H



Pesticide Use On Broccoli, Cabbage, Cauliflower And Peppers Grown In Connecticut: 1991, James J. Turner Ii, Candace L. Bartholomew Aug 1993

Pesticide Use On Broccoli, Cabbage, Cauliflower And Peppers Grown In Connecticut: 1991, James J. Turner Ii, Candace L. Bartholomew

Storrs Agricultural Experiment Station

No abstract provided.


Pesticide Use On Peaches And Pears Grown In Connecticut: 1991, James L. Turner Ii, Candace L. Bartholomew Jun 1993

Pesticide Use On Peaches And Pears Grown In Connecticut: 1991, James L. Turner Ii, Candace L. Bartholomew

Storrs Agricultural Experiment Station

No abstract provided.


Pesticide Use On Apples Grown In Connecticut: 1990, James L. Turner Ii, Candace L. Bartholomew Apr 1992

Pesticide Use On Apples Grown In Connecticut: 1990, James L. Turner Ii, Candace L. Bartholomew

Storrs Agricultural Experiment Station

No abstract provided.


Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter Jan 1992

Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter

OES Theses and Dissertations

The eggs of the Japanese medaka (Oryzias latipes) were employed in a number of studies to develop a routine, standardized assay which can assess the acute and sublethal impacts of individual toxicants and complex mixtures. The eggs of this Cyprinodont minnow were topically treated with each toxicant or mixture dissolved in membrane permeable dimethylsulfoxide (DMSO) solvent. Nine chemicals were initially evaluated with two, pentachlorophenol (PCP) and tributyltin chloride (TBTCl), subsequently selected for extensive evaluations of salinity tolerance and the accuracy of the topical exposure method for representing a typical immersion exposure. The amount of material actually penetrating the eggs was …


Bulletin No 4222 - Management Of Properties With Pesticide Residues - Information For Farmers With Properties Affected By Organochlorine Pesticide Residues, Farran Dixon Nov 1991

Bulletin No 4222 - Management Of Properties With Pesticide Residues - Information For Farmers With Properties Affected By Organochlorine Pesticide Residues, Farran Dixon

Bulletins 4000 -

This publication is produced by the Department of Agriculture to help farmers who have been affected by the pesticide residue problem. Some material from previous issues has been included, so that as much information as possible is contained in a single publication. We suggest you keep it as a convenient reference on any aspect of the residue problem.

All owners of affected land are urged to read this publication carefully. This applies to the owners of any land which has a soil organochlorine residue level greater than 0.1 parts per million (ppm).

A management notice will be issued for each …


Bulletin No 4219 - Chemical Control Of Insect Pests In Field Crops And Pastures, T. P. Quinn, G. P. Mangano, P. J. Michael Apr 1991

Bulletin No 4219 - Chemical Control Of Insect Pests In Field Crops And Pastures, T. P. Quinn, G. P. Mangano, P. J. Michael

Bulletins 4000 -

Chemicals currently registered in Western Australia for use against pests of field crops and pasture are given in the following tables. Trade names are listed alongside each chemical formulation.

Department of Agriculture Bulletin 4185 "Insect and allied pests of extensive farming" will help you identify the pest(s) through coloured photographs, descriptions and keys. Information on the type of damage, life cycle and control is also provided. Further information is available in Farmnotes on specific pests and on pests of a particular crop.

The Poison Schedule for each product is indicated in the table. Extremely toxic chemicals are labelled as "dangerous …


Gas Chromatographic Method For Determination Of 28 Volatile Organic Compounds Emitted From A Sewerage Plant, Yeming Sun Jan 1991

Gas Chromatographic Method For Determination Of 28 Volatile Organic Compounds Emitted From A Sewerage Plant, Yeming Sun

Theses

In this study, 28 volatile organic compounds (VOCs) emitted from the Linden Roselle Sewerage Authority Plant (LRSA) were monitered. The determination by gas chromatography (GC) is presented. This work emphasizes the collection of whole air samples, using a canister-based sampling system with cryogenic concentration. An appropriate temperature program was selected to obtain the best sample separation. The procedure for the identification of 28 standard gas mixture was achieved by comparing the chromatograms of sample with those of the specific groups of target compounds, as well as by comparing the sample with the results from GC Mass spectrometeric analysis. Because of …


Stabilization/Solidification Of Organic Containing Wastes Using Organophilic Clay And Coal Fly Ash, Edith Lagoutte Dec 1990

Stabilization/Solidification Of Organic Containing Wastes Using Organophilic Clay And Coal Fly Ash, Edith Lagoutte

Theses

The relative merits of eight different coal fly ashes for use in the stabilization/Solidification of a waste containing both heavy metals and pentachlorophenol were investigated. Also studied, was the possible use of either untreated or treated (with hexade-cyl ammonium bromide) clay to enhance the stabilization of the organic. The sample composition was : 62% foundry baghouse dust (or 60% if 2% clay as added to the sample), 4.5% cement, 14% coal fly ash, 19.5% water. Pentachlorophenol was chosen as represen¬tative of the organic contamination. All tests were performed after curing the samples at 22°C, 98% Rh for 28 days. The …


Benzo(A)Pyrene Ingested From Composite Meals : Analysis And Method Development Related To Total Human Exposure, Che-Han Hsu Jan 1990

Benzo(A)Pyrene Ingested From Composite Meals : Analysis And Method Development Related To Total Human Exposure, Che-Han Hsu

Theses

Polycyclic aromatic hydrocarbons including benzo[a]pyrene (BaP) have been known for many years to be environmental carcinogen. Moreover, B(a)P has often been used as an indi¬cator for the carcinogenic potency of environmental matter. One of its exposure pathways, ingestion, may possibly be more important than other routes, conventionally studied such as inhalation. The purposes of this thesis are 1) to analyze the B(a)P concentrations in weekly composite and some daily meals obtained in the Total Human Exposure to Environmental Substances (THEES) study, 2) to develop techniques which can measure the levels of B(a)P in foods accurately and effici¬ently, 3) to compare …


Degradation Of Refractory Organic Pollutants In Tar, Water And Soil Matrices By Ozone Or Hydrogen Peroxide With Ultraviolet Light, Liang-Jiun Uang Jan 1990

Degradation Of Refractory Organic Pollutants In Tar, Water And Soil Matrices By Ozone Or Hydrogen Peroxide With Ultraviolet Light, Liang-Jiun Uang

Theses

The objective of this research is to develop a method to degrade refractory Tar materials, higher molecular weight 3-5 ring Poly Aromatic Hydrocarbons (PAH's) or degrading these highly refractory PAH structures so that they are amenable to further treatment by biological or chemical methods. The process utilized to achieve this is to treat contaminated soils or tar materials with hydrogen peroxide or ozone plus ultraviolet light. Analysis of 27 specific PAH's was done by gas chromatograph (Flame Ionization Detection) for the reactants and products. The contaminated soil showed significantly lower levels of these PAH's after treatment.


Quantitative Determination Of Formaldehyde In Ambient Air, Wen-Shao Chou Jan 1990

Quantitative Determination Of Formaldehyde In Ambient Air, Wen-Shao Chou

Theses

Formaldehyde has been shown in the laboratory to play a critical role in the chemistry of polluted air. The method which we discuss in this paper was evaluated under practical field conditions in the Northern New Jersey Staten Island Urban Air Toxics Project. Formaldehyde in ambient air is concentrated and derived by passing a known quantity of air through a silica column impregnated with 2,4-dinitrophenylhydrazine (DNPH). The silica is eluted with acetonitrile and the concentration of formaldehyde is determined by High Performance Liquid Chromatograph (HPLC) with UV detection. A description of procedural details for coating silica cartridges with 2,4-DNPH acidified …


Microbial Competition In The Biodegradation Of Phenol, Mary Ellen Frank May 1989

Microbial Competition In The Biodegradation Of Phenol, Mary Ellen Frank

Theses

Three phenol degraders were isolated from the mixed liquor of the Livingston, NJ municipal treatment plant. Shaker flask experiments using one of the degraders (a Pseudomonas sp.) resulted in the determination of its kinetic rate constants. The second phenol degrader (a Xanthamonas) lost its phenol degrading ability while being stored, and its kinetic rate constants could not be determined. The third phenol degrader (a Pseudomonas cepacia) formed flocs which interfered with the spectrophotometric determination of biomass and therefore its kinetic rate constants also could not be determined.

Mixed culture experiments were carried out using a the Pseudomonas sp. and a …


Thermal Desorption Of Hazardous And Toxic Organic Compounds, Manuel S. Nolau May 1989

Thermal Desorption Of Hazardous And Toxic Organic Compounds, Manuel S. Nolau

Theses

The purpose of this thesis is to study the thermal desorption behavior of toxic organic compounds, specifically o-xylene, p-xylene, ethyl benzene, p-chlorotoluene, and anthracene, from soil with respect to temperature and time, and to develop a mathematical model that will describe this desorption behavior. The model will allow prediction of the concentration of an organic contaminant in commercial soil desorption system over time given a known set of parameters of the specific chemical as well as flow rate and temperature. For this purpose, two sets of experiments were done: These are identified as 1. Thermal desorption and 2. plug flow …


Study Of An Analytical Method For Benzo(A)Pyrene Metabolites In Human Urine, Zheng Ouyang May 1989

Study Of An Analytical Method For Benzo(A)Pyrene Metabolites In Human Urine, Zheng Ouyang

Theses

A method developed by Becher and Bjorseth for analysis of PAH metabolites in urine was employed to investigate human exposure to benzo(a)pyrene (BaP) - an ubiquitous environmental carcinogen. Preliminary results are presented showing the relationship between exposure to BaP and urinary elimination. Although the correlation between the two variables is not statistically significant, there appears to be a positive association with selected exposure varibles such as smoking. The identification of an association may establish urinary BaP as a marker of exposure.

However, detailed study of the analytical procedure indicated that recoveries with this method were as low as 3-8% for …


Environmental Assessment In Bioethanol Technology Using Immobilized Yeast Cells, Minoo Kandy Zarnegar Jan 1989

Environmental Assessment In Bioethanol Technology Using Immobilized Yeast Cells, Minoo Kandy Zarnegar

Theses

This study is undertaken from the standpoint of water pollution evaluation in bioethanol technology, using immobilized yeast cells. Evaluation of water pollution caused by immobilized yeast fermentation is the main objective of this research.

The pollution in water remaining at the end of ethanol production, which is normally discharged in the wastewater stream, has been analyzed by the measurement of biological oxygen demand (BOD), since BOD measurement is one of the widely used parameters for water pollution evaluation. BOD obtained from produced water (stillage) was between the range of 115- 360 mg/l. The variation in BOD depended upon the removal …