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Topic: Reference dose

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lethal dose

equivalent dose

Reference dose

Dose response

dose response curve

Lowest published lethal dose

Curt Dose

Death in Small Doses

Collective dose

Radiation Absorbed Dose

infectious dose

Mixed dose

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	Environmental Health Perspectives: Biologically Based Pesticide Dose Estimates for... @ HighBeam Research (Site not responding. Last check: 2007-10-29)
		Dose estimates were adjusted either by daily creatinine or daily urine volume output for children 0-6 years of age in an agricultural community, based on urinary concentrations of two of the three dialkylphosphate metabolites (DMTP and DMDTP) common to the dimethyl OP pesticides.
		The percentage of children exceeding the azinphos-methyl ADI was 19% for agricultural children and 22% for reference children; 3% of the agricultural children and none of the reference children exceeded the phosmet ADI.
		Underlying the estimation of doses from urinary metabolite concentrations in this study were the assumptions that spot urine samples are representative of total daily excretion (steady-state assumption), and that dialklyphosphate concentrations are equivalent to OP pesticide absorbed doses on a molar basis.
	www.highbeam.com /library/doc0.asp?DOCID=1G1:63937870&refid=ip_encyclopedia_hf (4678 words)

	Guidelines on Patient Dose to Promote the Optimisation of Protection for Diagnostic Medical Exposures: Report of an ... (Site not responding. Last check: 2007-10-29)
		Reference doses should remain the priority target for all departments in which typical doses are above current reference dose values, and their use should be extended to other areas of diagnostic investigation.
		Achievable doses should be used as a supplement to the existing reference dose values of entrance surface dose per radiograph when departments are assessing the results of local dose surveys conducted for the purposes of reviewing patient protection.
		Reference doses should be established in collaboration with appropriate professional bodies on the basis of published dose data from wide-scale surveys of dental practice.
	www.phls.co.uk /radiation/publications/documents_of_nrpb/abstracts/absd10-1.htm (1043 words)

	Respiratory Tract Dosimetry Model (Site not responding. Last check: 2007-10-29)
		The methodology allows lung dose predictions to e determined as probability distributions, which better reflect the potential spread in doses for members of population groups than a single reference dose.
		Doses resulting from inhalation of plutonium oxide, uranium oxide, and uranium octoxide (aerodynamic diameters ranging from 0.1 to 50 microns) were initially investigated with LUDUC to demonstrate the methodology.
		Median doses for plutonium oxide, uranium oxide, and uranium octoxide generally agree with reference dose values, providing some level of confidence in the reference-man approach.
	www.physics.isu.edu /colloquium/farfan04.html (417 words)

	SDV Nuclear Glossary (Site not responding. Last check: 2007-10-29)
		A measure of dose in which the type of radiation and the sensitivity of tissues and organs to that radiation is taken into account.
		It represents a dose equivalent or a dose that is correlated with injury due to radiation exposure.
		The sievert is the SI unit of absorbed dose; 1 rem is equivalent to 0.01 sievert.
	glossary.dataenabled.com /sdvglossary_dose.html (1642 words)

	Nat' Academies Press, Review of the U.S. Army's Health Risk Assessments for Oral Exposure to Six Chemical-Warfare ...
		BENCHMARK DOSE Because of shortcomings in the use of NOAELs to determine doses with low risk, Crump (1984) proposed that the NOAEL be replaced by a benchmark dose (BD) associated with a biological effect.
		The BD is a dose with a specified low level of excess health risk, generally in the range of 1% to 10%, that can be estimated from data with little or no extrapolation outside the experimental dose range.
		Swartout (1996) observed that the 95th percentile for the ratio of subchronic to chronic doses for NOAELs or LOAELs was 17.
	www.nap.edu /books/0309065984/html/17.html (2496 words)

	IRIS Glossary of Terms
		That is, at dose d, an additional 10% of the population is expected to respond adversely.
		Reference Concentration (RfC): Definition applied prior to July 2005: An estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.
		Reference Dose (RfD): Definition applied prior to July 2005: An estimate (with uncertainty spanning perhaps an order of magnitude) of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.
	www.epa.gov /iris/gloss8.htm (5840 words)

	ICRU News
		For planar and concave sources, the Reference Point is located at a distance of 1 mm measured from the center of the source surface along the axis of symmetry of the source.
		For example, in intravascular brachytherapy, the depth at which the dose is specified should be the same for beta sources and low-energy photon or gamma sources.
		Presently for intravascular brachytherapy applications for coronary arteries, doses are currently prescribed, recorded and reported at the inner surface of the arterial wall (endothelium) and at a depth of 1 mm in the arterial wall.
	www.icru.org /n_002_3.htm (945 words)

	3.3 Noncarcinogenic Chemical Health Impacts (Site not responding. Last check: 2007-10-29)
		The hazard quotient is the ratio of the average daily dose to the reference dose.
		The reference dose is defined by the USEPA for many chemicals for ingestion and inhalation intakes (USEPA 1993).
		The reference dose represents a level that is believed to be safe for members of the general population.
	mepas.pnl.gov /earth/formulations/exposure/3.0/3_3.html (211 words)

	Questions and Answers: The Facts on Perchlorate in Drinking Water
		A: A reference dose (RfD) is defined by EPA as, "an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily oral exposure to the human population (including sensitive subgroups) that is likely to be without risk of deleterious effects during a lifetime." (http://www.epa.gov/iris/gloss8.htm)
		This dose is already 57-fold lower than the dose that the NAS Committee identified as the minimum dose before any adverse effects of perchlorate exposure could occur.
		Any level of exposure below the Committee's reference dose of 245 ppb is clearly safe, since no adverse effect can occur to anybody, including pregnant women, their fetuses, infants, and children, at levels of exposure that are below the highest dose at which no effects at all occur.
	www.councilonwaterquality.org /know/qa_nas.html (2569 words)

	What reference doses should we use? (Site not responding. Last check: 2007-10-29)
		Reference doses of 4 mGy (patient entrance dose) for an adult mandibular molar intra-oral radiograph and 65 mGy mm (dose-width product) for a standard adult panoramic radiograph are recommended.
		Although dental radiographs contribute only a small amount to the collective radiation dose of the UK population, when such high numbers of radiographs are involved there is always scope for dose reduction.
		It is primarily the 25% who expose patients to doses in excess of this (and he shows that some are far in excess of this) that are recommended to implement urgent dose control.
	www.nature.com /bdj/journal/v186/n8/full/4800119a2.html (838 words)

	SERA Manual - Section 8
		The boron dose weight factor also includes the boron concentration, and the gamma dose weight factor includes the total gamma source for each field, which consists of both the source gamma and the capture gamma source from neutron capture in tissue, and the gamma repair factor (see Section 8.3.1.3.4) from the input display.
		Doses may be computed at a point, along a line, as contours on a plane, or they may be integrated over a volume.
		This dose component will be the only component compared for the Volume reference dose search (see Section 8.4.1.9), where the reference dose is the dose at the center of the edit voxel with the highest value of the selected dose component.
	www.cs.montana.edu /~bnct/manual/sec08.html (4275 words)

	Abstract from 1994 SRA Annual Meeting (Site not responding. Last check: 2007-10-29)
		A reference dose is obtained by dividing a no observed adverse effect level (NOAEL) or benchmark dose, corresponding to a low level of health risk, in animals by uncertainty (safety) factors to account for potentially greater sensitivities of humans to a chemical.
		It is assumed that the risk of adverse biological effects below the reference dose is negligible, but generally no attempt is made to estimate the potential risk at the reference dose.
		The relationship between the benchmark dose, experimental measurement variability, and range of abnormal responses is discussed.
	www.riskworld.com /Abstract/1994/sraam94/ab4aa106.htm (255 words)

	931. Fenthion (Pesticide residues in food: 1997 evaluations Part II Toxicological & Environmental)
		Brain acetylcholinesterase activity was inhibited by 76% in animals at the intermediate dose and by 86% in those at the high dose; in rats at the low dose, it was inhibited by 4% in males and 9% in females, the latter being statistically significant.
		Comments In rats treated by gavage with single doses of 0, 1, 50 (males), 75 (females), 150 (males), or 225 (females) mg/kg bw of technical-grade fenthion, the NOAEL for inhibition of brain acetylcholinesterase activity and for neurobehavioural effects was 1 mg/kg bw.
		The Meeting concluded that an acute reference dose of 0.01 mg/kg bw could be allocated by taking into account the NOAEL of 1 mg/kg bw in rats and applying a safety factor of 100.
	www.inchem.org /documents/jmpr/jmpmono/v097pr08.htm (581 words)

	ATSDR - Health Consultation - Olean Well Field, Olean, Cattaraugus County (Site not responding. Last check: 2007-10-29)
		This dose was then compared to a risk reference dose (estimated daily intake of a chemical that is likely to be without an appreciable risk of health effects) developed by the US EPA, ATSDR and/or NYS DOH.
		Thus, the risk reference dose is not expected to cause health effects because it is selected to be much lower than dosages that do not cause adverse health effects in laboratory animals.
		If exposure to the contaminant exceeds the risk reference dose, there may be concern for potential noncancer health effects because the margin of protection is less than that afforded by the reference dose.
	www.atsdr.cdc.gov:8080 /HAC/PHA/olean/owf_p4.html (1067 words)

	Report assesses health implications of perchlorate ingestion (Site not responding. Last check: 2007-10-29)
		The most recent EPA risk assessment, published in 2002, proposes a daily reference dose of 0.00003 milligrams per kilogram (mg/kg) of body weight, which the agency said would correspond to a drinking-water concentration of 1 part per billion based on certain assumptions about body weight and daily water consumption.
		The committee that wrote the Research Council report did not include a corresponding drinking-water concentration with its reference dose because the assumptions that are used to derive drinking-water standards involve public-policy choices that were beyond the committee's charge.
		The committee emphasized that the reference dose should be based on inhibition of iodide uptake by the thyroid in humans, which is not an adverse effect but the key biochemical event that precedes any health effects caused by perchlorate exposure.
	www.eurekalert.org /pub_releases/2005-01/tna-rah012505.php (1109 words)

	Pesticide residues in food: 2002 - FENAMIPHOS
		Fenamiphos was first evaluated toxicologically by the 1974 JMPR (Annex 1, reference 22), when an ADI of 0–0.0006 mg/kg bw was allocated on the basis of the results of a 2-year study in dogs in which inhibition of plasma cholinesterase activity was observed.
		In the third trial, fenamiphos was administered at a dose of 1 mg/kg bw to two males and two females, blood being taken for estimation of plasma and erythrocyte cholinesterase activity before administration of the test material and 1, 2, 4 and 24 h later.
		In the second trial doses of 0.5 or 2 mg/kg bw were used and in the final trial the dose was 1 mg/kg bw.
	www.inchem.org /documents/jmpr/jmpmono/2002pr06.htm (1767 words)

	Official reference dose set for perchlorate
		This level is consistant with the recommended reference dose included in the National Academy of Science's January 2005 report.
		A reference dose is a scientific estimate of a daily exposure level that is not expected to cause adverse health effects in humans.
		EPA's reference dose for perchlorate will be posted on the agency's online IRIS database, which contains risk information on possible human health effects from exposure to chemical substances in the environment.
	www.caprep.com /0205044.htm (245 words)

	Protecting Children From Toxic Threats (Site not responding. Last check: 2007-10-29)
		The reference dose is the upper limit of exposure thought to be "safe." The CDC report implies that the reference dose has a built in margin of safety, so exceeding it is not a problem, but this is false assurance.
		The current reference dose is not adequately protective, for a variety of reasons.
		In addition, the current reference dose is derived from an exposure level associated with a DOUBLING of disability, while reference doses are usually derived from exposures that are associated with NO effects (called "no effects levels" or "NOELS").
	www.mtn.org /iasa/childtoxins.html (362 words)

	Environmental Chemistry Research Guide
		The DOSE reference set contains data on 4123 chemicals which have been studied for environmental impact or toxicity.
		Reference management programs allow you to build a personal database of your references to articles, books, websites - any information source - and then easily create bibliographies and reference lists using any particular style, without having to retype or reformat.
		RefWorks is a web-based reference management program that allows users to create their own personal database of references by importing references from online databases (eg SciFinder Scholar or Inspec).
	www.dartmouth.edu /~krescook/instruct/envirochem.shtml (1450 words)

	Dose Calibrator Reference Sources
		The daily calibration of dose calibrators is recommended to ensure accurate and reproducible instrument response.
		Dose Calibrator Reference Sources are registered with the U.S. Food and Drug Administration Center for Devices and Radiological Health and the U.S. Nuclear Regulatory Commission.
		Dose Calibrator Reference Sources are available individually or as an economical set.
	www.biodex.com /radio/dosecal/dose_562feat.htm (190 words)

	Water Quality Laboratory
		In the above statement, the Environmental Working Group clearly implies that food standards are enforced in a manner that would preclude individuals from being exposed at levels in excess of the reference dose, a dose that is the basis for calculating the MCL of drinking water standards.
		While it is true that a single detection of a residue in excess of federal food residue limits (food tolerance levels) is a violation of federal food law, this has no connection to whether or not a pesticide dose in a particular day exceeds a reference dose.
		A residue in excess of the food tolerance level is a violation of the law because it directly implies that the pesticide was applied at rates in excess of the label or that the crop was harvested sooner than legally allowed (EPA 1994b).
	www.heidelberg.edu /wql/WQL.EWGreview06.html (491 words)

	Benchmark Calculations for Perchlorate from Three Human Cohorts
		The benchmark dose for a particular serum indicator was defined as the dose predicted to cause an additional 5 or 10% of persons to have a serum measurement outside of the normal range.
		Because the dose estimates based on the urine data were only for the third shift, and because of the uncertainty in both the void time for the urine samples and the rate of creatinine elimination, the average dose per shift over the three shifts obtained from the serum data were used in the benchmark analysis.
		Site-specific reference dose for methylmercury for fish-eating populations.
	ehp.niehs.nih.gov /members/2005/7814/7814.html (7321 words)

	Senator Feinstein questions EPA’s process to establish perchlorate reference dose
		In January 2005, the National Academy of Sciences recommended a reference dose for perchlorate exposure (the amount that is believed to be safe to consume per individual at a given body weight per day).
		In February 2005, EPA issued a reference dose, without any comment from the general public or the scientific community.
		"I am writing you regarding the process that led the EPA to adopt the perchlorate reference dose (RfD) that was recommended by the National Academy of Science in the report on the ‘Health Implications of Perchlorate Ingestion’ released in January 2005.
	www.caprep.com /0605025.htm (405 words)

	American Water Works Association (Site not responding. Last check: 2007-10-29)
		USEPA announced it has adopted an official perchlorate reference dose of 0.7 micrograms/kg/day to match that recommended last month by an expert panel of the National Academy of Sciences (NAS).
		USEPA noted that the reference dose already reflects a 10-fold safety factor to account for the greater risk perchlorate poses to fetuses of pregnant women who might have hypothyroidism or iodide deficiency.
		USEPA’s adoption of a perchlorate reference dose, details of which are given at the agency’s Integrated Risk Information System, is an essential step toward regulating the rocket-fuel chemical that has been turning up in water supplies across the United States, especially in California, which is expected to regulate it this year.
	www.awwa.org /Communications/news/index.cfm?ArticleID=406 (399 words)

	[No title]
		It is not necessary for the Reference Group to have no dose at all, since the difference in cumulative cancer death-rate between any two compared groups will be divided by the DIFFERENCE in dose (not by the entire dose of the group with higher exposure).
		Likewise, the individuals in the Reference Group, and their observed cancer death-rate, are the same in the two analyses.
		As the older age-bands ATB continue passing from the scene, it is self-evident that both the spontaneous and the radiation-induced cancers coming in the A-bomb survivors, beyond 1982, have to come primarily from the younger age-bands -- in great contrast to the source of the cancers observed between 1950-1982.
	www.ratical.org /radiation/CNR/RIC/chp13.txt (5229 words)

	The History of Perchlorate: Evolving Science, Technologies and Regulations
		U.S. EPA peer review panel concludes a "draft" Reference Dose of 32 ppb level is probably overly cautious and recommends additional study.
		U.S. EPA relies primarily on animal studies, particularly a scientifically flawed and controversial rat study, to propose new "draft" Reference Dose of 1 ppb.
		U.S. EPA establishes its official reference dose of perchlorate at 0.0007 milligrams per kilogram per day and translated that number to a Drinking Water Equivalent Level of 24.5 ppb.
	www.councilonwaterquality.org /science/history.html (559 words)

	SERA Manual - Appendix D
		Various integral quantities for dose and flux may be computed and printed, without any influence on the transport calculation.
		The reference dose parameters influence the determination of the reference dose values, and thus they must precede any active edit directives.
		Dose-volume histogram data are calculated for all dose components, and for the total dose, using the previously specified RBE values, isotope densities, and boron concentrations.
	www.cs.montana.edu /bnct/manual/appD.html (2185 words)

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