Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Bioaccumulation - Wikipedia, the free encyclopedia To bioaccumulate literally means to accumulate in a biological system. Bioaccumulation can be divided into bioconcentration and biomagnification. If the input of a toxic substance to an organism is greater than the rate at which the substance is lost, the organism is said to be bioaccumulating that substance. en.wikipedia.org /wiki/Bioaccumulation   (619 words)

EXTOXNET TIBs - Bioaccumulation Bioconcentration is the specific bioaccumulation process by which the concentration of a chemical in an organism becomes higher than its concentration in the air or water around the organism. Bioaccumulation is a normal and essential process for the growth and nurturing of organisms. Bioaccumulation is a normal process that can result in injury to an organism only when the equilibrium between exposure and bioaccumulation is overwhelmed, relative to the harmfulness of the chemical. extoxnet.orst.edu /tibs/bioaccum.htm   (1906 words)

Bioaccumulation Bioaccumulation means an increase in the concentration of a chemical over time in a biological organism compared to the chemical's concentration in the environment. Understanding the dynamic process of bioaccumulation is very important in protecting human beings and other organisms from the adverse effects of chemical exposure, and it has become a critical consideration in the regulation of chemicals. Bioaccumulation is a normal process that can result in injury to an organism only when the equilibrium between exposure and bioaccumulation is overwhelmed. www.sph.uth.tmc.edu /course/envi/gdshtms/Bioaccumgds.htm   (1800 words)

Bioaccumulation Bioaccumulation is a process by which the concentration of a chemical increase over time in a biological organism compared to the chemical's concentration in the environment. Understanding the dynamic process of bioaccumulation is very important in protecting human beings and other organisms from the adverse effects of chemical exposure, and it has become a critical consideration in the regulation of chemicals and bioconcentration factor. Determination of the BCF (Bioaccumulation Factor) is extremely important in the risk analysis of a compound (PCBs). www.ccny.cuny.edu /social_science/kfoster/eep/people/bioaccum.htm   (677 words)

RMP Report: Bioaccumulation of Contaminants by Transplanted Bivalves The objectives of the LEMP were to evaluate the bioaccumulation of contaminants in transplanted bivalves in the vicinity of sewage outfalls compared to bioaccumulation in control or reference areas. Evaluation of bioaccumulation along a waste discharge gradient, as has been done by the LEMP, also provides an indication of whether or not the outfalls may be directly contributing to the contaminant load available for bioaccumulation. Bioaccumulation of contaminants by bivalve mollusks in the vicinity of Municipal wastewater discharges to San Francisco Bay. www.sfei.org /rmp/reports/bioaccumulation/bioaccumulation.html   (8129 words)

Bioaccumulation   (Site not responding. Last check: 2007-11-06) It was known by the native peoples of the arctic that the livers should not be eaten, but Arctic explorers have suffered vitamin A poisoning from eating the bear livers (and there has been at least one example of similar poisoning of Antarctic explorers eating husky dog livers). Bioaccumulation means an increase in the concentration of a chemical in a... Bioaccumulation is a general term for the accumulation of substa www.serebella.com /encyclopedia/article-Bioaccumulation.html   (1179 words)

DEVELOPMENT AND APPLICATION OF METHODS FOR ASSESSING BIOAVAILABILITY OF CONTAMINANTS ASSOCIATED WITH SEDIMENTS: II. ... Bioaccumulation assays have been characterized to assure that the method is appropriate for studying a wide range of nonpolar organic compounds, and that the results obtained reflect bioavailability under field conditions. Studies of metal bioaccumulation from sediments have also proved to be useful tools for assessing ecological risks from metal-contaminated sediment and for investigating influences on bioavailability and mobility of metals in sediments. Bioaccumulation tests with larvae of the midge, Chironomus tentans, found that bioavailability of Cu was negatively associated with concentrations of AVS and organic carbon in sediments (Besser et al. water.usgs.gov /osw/techniques/workshop/besser.html   (1783 words)

Endocrine Modulation - bioaccumulation Bioaccumulation or biomagnification is the process by which contamination of the environment by persistent chemicals, including endocrine disrupters and other toxicants, leads to the accumulation of these chemicals by an entire ecosystem. It is these chemicals that are persistent, stable and lipophilic that may be bioaccumulated by animals and eventually humans. Northern populations may be uniquely susceptible to bioaccumulation of certain toxicants because of their culture, lifestyle and diet. www.emcom.ca /EM/bio.shtml   (367 words)

National Sediment Bioaccumulation Conference Proceedings Summary -- U.S. EPA   (Site not responding. Last check: 2007-11-06) Results of bioaccumulation tests are used in the assessment of new and existing industrial chemicals under the Toxic Substances Control Act and in the review process for National Pollutant Discharge Elimination System (NPDES) permits and dredged material discharge permits. Bioaccumulation studies are also required to support registration of pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act. EPA sponsored the National Sediment Bioaccumulation Conference during September 11-13, 1996 in Bethesda, Maryland. www.epa.gov /OST/cs/confprod.html   (395 words)

Bioaccumulation of Inventory of Radionuclide Elements - Part 1 Bioaccumulation is a more general term, with biomagnification describing a special type of bioaccumulation usually associated with dynamics of organismal food webs and the cycling of chemicals through biotic assemblages and ecosystems. The fundamental parameter expressing bioaccumulation is the bioaccumulation factor, a dimensionless ratio of the concentration, activity level, or similar entity of a chemical within a given tissue to its comparable concentration, activity level, etc., in the source material to which the tissue is exposed. Bioaccumulation factors based on the consumption of plants and invertebrates, or on organisms found in benthic or sediment environments relative to the sediments are not given. www.ijc.org /rel/boards/nuclear/bio/part1.html   (9455 words)

Bioaccumulation Definition Page Bioaccumulation is a general term for the accumulation of substances, such as pesticides (DDT is an example), methylmercury, or other organic chemicals in an organism or part of an organism. Bioconcentration differs from bioaccumulation because it refers only to the uptake of substances into the organism from water alone. Bioaccumulation of Mercury by Fish and Fish-Forage Organisms in Camp Far West Reservoir, Yuba and Placer Counties, California toxics.usgs.gov /definitions/bioaccumulation.html   (460 words)

Bioaccumulation of Inventory of Radionuclide Elements - Part 2 From Tables 6 and 7, it appears that the bioaccumulation factors for sodium in plant parts are of the order of magnitude of 100-2500 relative to the aquatic environment and the biomagnification factor for the aphid relative to the plant parts is about 1-4. For potassium the bioaccumulation factors for the plant parts relative to the water are 1000-3000 and for the aphid relative to the plant parts is about 1-2. The bioaccumulation of silica suggests that it might be a macronutrient in plants other than diatoms, but as earlier indicated, many silica analyses may be faulty because of analyses of silica on the material rather than silica in the material. www.ijc.org /rel/boards/nuclear/bio/part2.html   (8556 words)

Interpreting Bioaccumulation Data   (Site not responding. Last check: 2007-11-06) Making regulatory decisions regarding what level of bioaccumulation is or is not acceptable must be based on data that link a given concentration of substance "X" with measurable biological effects, e.g., reduced survival, growth, or reproduction. Bioaccumulation data are evaluated at two levels of interpretation according to current dredged material evaluation guidance. At the first level, the amount of bioaccumulation of a specific contaminant in dredged material-exposed organisms is compared to a numerical effect limit, such as a Food and Drug Administration action level or a fish advisory. el.erdc.usace.army.mil /ered/interpre.html   (352 words)

ES&T Online News: Bioaccumulation assessments point to pressing data gaps Of "P, B, and T", bioaccumulation is the most problematic because far fewer data exist for this characteristic than for the others, according to Danie Dubé, chief of the chemical strategy division of Environment Canada. For example, in traditional bioaccumulation assays, fish are exposed to a chemical in water. She adds that to evaluate bioaccumulation, Environment Canada currently uses models developed by Frank Gobas at Simon Fraser University, by Syracuse Research Corp. and EPA's Office of Pollution Prevention and Toxics, and by Ovanes Mekenyan at Bourgas Prof. pubs.acs.org /subscribe/journals/esthag-w/2005/apr/tech/rr_bioaccumulation.html   (963 words)

RMP Reports: Bioaccumulation Workshop Consensus on the various opinions and recommendations was not necessarily achieved at the workshop and this document seeks to synthesize the current state of knowledge concerning the transplanted bivalve method, and provides recommendations for improving and streamlining the program that are consistent with the general direction of discussions at the workshop. It is not known whether the low accumulations in the transplants are due to poor bioaccumulation or ambient concentrations that are similar between the source locations and the Estuary. Because bivalve species differ in their bioaccumulation characteristics, site comparisons are limited to those with the same species and sites with the same species do not necessarily overlap with the geographic definition of reach. www.sfei.org /rmp/reports/bivalve_recs/bivalve_recs.html   (4002 words)

Are Persistence, Bioaccumulaton and Toxicity (PBT) Appropriate Criteria for Ranking the Hazards of Inorganic Metals and ... In the case of soluble organic substances, surrogate data such as persistence and bioaccumulation have been used, in combination with toxicity, for the purpose of hazard categorization. In fact, the criteria and test methods to evaluate persistence ("lack of degradability") and bioaccumulation ("water-octanol partition coefficient") were developed to be used in combination with toxicity in order to reduce the importance given to the use of toxicity data alone. Again, the science is clear: bioaccumulation as used for assessing the hazard of synthetic organic chemicals does not apply to the hazard assessment of inorganic metals or metal compounds. www.icmm.com /industry_questdetail.php?rcd=1   (944 words)

SOFIA - Poster - The South Florida Mercury Science Program - Background   (Site not responding. Last check: 2007-11-06) For a predator, bioaccumulation is compounded because there is an increasing concentration of methylmercury in each successive link of its aquatic food chain. Bioaccumulation creates a risk of toxicity to fish-eating humans and other predators at the top of a food chain. Bioaccumulation of mercury in several species of game fish, including the economically important largemouth bass, has made fish consumption advisories necessary to protect human health (Figure 3). sofia.usgs.gov /publications/posters/merc_program/index.html   (1416 words)

Landfills and Water Quality Management Based on the discussions at the US EPA's National Sediment Bioaccumulation Conference, the only reliable approach today for determining whether there is excessive bioaccumulation in a particular type of organism that is present in a particular waterbody during a certain time of the year is to actually measure the tissue residues in that organism. The basic problem with the various approaches that are being used to estimate bioaccumulation is that none of them properly incorporates the aquatic chemistry and transport fate information in estimating tissue residues in an aquatic organism based on either sediment and/or water concentrations of the chemical of concern. The primary focus of concern with respect to bioaccumulation of hazardous chemicals must be on those chemicals that bioaccumulate to a sufficient extent in animal organism tissue to cause the organism to be considered hazardous to those who use the organism as a source of food. www.gfredlee.com /urb_pest.html   (13618 words)

Bioaccumulation   (Site not responding. Last check: 2007-11-06) Bioaccumulation factors were obtained from a variety of sources. Table 8 in Attachment 4-1 Exposure factors and bioaccumulation models for derivation of wildlife Eco-SSL. Literature-derived bioaccumulation models for earthworms: development and validation. www.tiem.utk.edu /~sada/helpv4/bioaccumulation.html   (701 words)

January 2002 mussel bioaccumulation exceedance notification Below is a discussion of the mussel bioaccumulation test, the likely sources of the elevated contaminants, Deer Island Treatment Plant effluent quality, and environmental conditions in Massachusetts Bay that could have affected the results. Because mussels bioaccumulate contaminants from the water, these shellfish are useful for assessing local concentrations of many contaminants, and have been used widely for two decades as a sensitive water quality monitoring tool. Although the mussel bioaccumulation test at the outfall site exceeded the Contingency Plan Caution Level threshold for PAH and chlordane, it should be stressed that these contaminants were found at very low levels. www.mwra.state.ma.us /harbor/html/20020125amx.htm   (1382 words)

Environmental effects of pharmaceuticals: The environmental hazard assessment of the pharmaceutical substance is based on criteria for biodegradability, potential for bioaccumulation and toxicity to aquatic organisms. Thus, a pharmaceutical substance that is readily degradable, has no potential to bioaccumulate,  and has a low toxicity receives a PBT index of 0. Furthermore, a substance that is not readily degradable, has a potential to bioaccumulate and a very high toxicity receives a PBT index of 9. www.noharm.org /details.cfm?ID=1034&type=document   (755 words)

Bioaccumulation & Biomagnification Bioaccumulation refers to how pollutants enter a food chain; biomagnification refers to the tendency of pollutants to concentrate as they move from one trophic level to the next. If it does bioaccumulate and biomagnify, much of the DDT will be in the bodies of organisms. As the first of the modern pesticides, it was overused, and soon led to the discovery of the phenomena of insect resistance to pesticides, bioaccumulation, and biomagnification. www.marietta.edu /~biol/102/2bioma95.html   (1270 words)

Human Dietary Exposure Bioaccumulation   (Site not responding. Last check: 2007-11-06) bioaccumulation is very important in protecting human beings and other organisms from the adverse effects of chemical exposure... Bioaccumulation of selenium (Se) in the fish community of Pigeon River/Pigeon Lake, which receives inputs and Se from a coal fly ash disposal facility, was studied to assess potential hazards of... Bioaccumulation ofmethylmercury in aquatic food chains is of interest, because it is generally the most important source ofnonoccupational human exposure... www.dietspots.com /93/human-dietary-exposure-bioaccumulation.html   (603 words)

COAST - Marine & Aquatic Pollution Activities - Bioaccumulation Bioaccumulation occurs when toxic substances accumulate in higher and higher concentrations from one level of a food chain to the next. Research the effects of bioaccumulation in several species (eagles and alligators). Have students write a report on what bioaccumulation is and how it affects humans. www.coast-nopp.org /resource_guide/elem_mid_school/ma_pollution_acts/bio.html   (477 words)

Bioaccumulation   (Site not responding. Last check: 2007-11-06) To bioaccumulate literally means to accumulate in a system. The problem arises when toxic substances stay the body for a long period of They are not acutely poisonous otherwise they would kill straight away are associated with chronic poisoning. It was known by the peoples of the arctic that the livers not be eaten but Arctic explorers have vitamin A poisoning from eating the bear (and there has been at least one of similar poisoning of Antarctic explorers eating husky dog livers). www.freeglossary.com /Bioaccumulation   (553 words)

People at MSRC Some of this work has explored the nature of binding of metals to diverse types of particles and the influence these have on the extent to which the metals are in a biologically available form. The effects of chemical and phase (particulate, dissolved, colloidal) partitioning of metals on their bioaccumulation in marine food webs are assessed. Bioaccumulation of Metals and Radionuclides in Marine Organisms. www.msrc.sunysb.edu /people/fisher.htm   (766 words)

Bioaccumulation Testing and Interpretation for the Purpose of Sediment Quality Assessment: Status and Needs   (Site not responding. Last check: 2007-11-06) We prepared this document to serve as a status and needs summary of the use of bioaccumulation data. This document was also prepared to respond to increased interest in the fate and effects of persistent, bioaccumulative, and toxic (PBT) pollutants, as evidenced The purpose of this document is to describe existing knowledge on the use of bioaccumulation data as part of sediment quality assessments. www.epa.gov /ost/cs/biotesting   (211 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.