background level


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level

 [lev´el]
relative position, rank, or concentration.
l's of care the six divisions of the health care system: preventive care, primary care, secondary or acute care, tertiary care, restorative care, and continuing care.
background level the usual intensity of a chemical or other stimulus in the environment.
confidence level the probability that a confidence interval does not contain the population parameter.
l's of consciousness see levels of consciousness.
lowest observed adverse effect level (LOAEL) (lowest observed effect level (LOEL)) in studies of the toxicity of chemicals, the lowest dosage level at which chronic exposure to the substance shows adverse effects; usually calculated for laboratory animals.
no observed adverse effect level (NOAEL) (no observed effect level (NOEL)) in studies of the toxicity of chemicals, the highest dosage level at which chronic exposure to the substance shows no adverse effects; usually calculated for laboratory animals.
level of significance a statistical measure that serves as the cutoff point used to determine whether a null hypothesis is retained or rejected; the probability of incorrectly rejecting the null hypothesis (see Type I error).
sterility assurance level (SAL) the probability that a process makes something sterile (see sterilization). An SAL of 10−6 is the recommended probability of survival for organisms on a sterilized device. This level means that there is less than or equal to one chance in a million that an item remains contaminated or nonsterile.

back·ground lev·el

the concentration (usually low) at which a substance or agent is present or occurs at a particular time and place in the absence of a specific hazard under investigation; an example is the background level of ionizing radiation.

background level

the usual intensity of a chemical or other stimulus in the environment.

background level

A typical or average environmental level of a chemical, toxin or isotope under native conditions.

back·ground lev·el

(bakgrownd levĕl)
Concentration (usually low) at which a substance or agent is present or occurs at a particular time and place in the absence of a specific hazard under investigation.
References in periodicals archive ?
In an attempt to avoid a legislative veto of the state Groundwater Protection Standard requiring treatment to background levels, the Pennsylvania Department of Environmental Resources has published guidance documents on property assessment procedures, as well as methods for conducting cleanups and calculating cleanup criteria based on a risk-assessment model.
Figure 4 Completed Worksheet Positive factors Negative factors Sound transmission class 45 Normal voice 62 (STC) Background level NC 42 Voice correction 10 Wall STC correction 7 STC reduction 8 Background correction 0 Total 87 Total 87
The variance is defined in terms of the observed counts and estimated background level as [[sigma].
How will performance be affected by possible background levels of illicit substances found on "clean" mail?
This is the most stringent regulatory standard in the United States: The NRC relies on a 25 millirem standard while the EPA uses a 15 millirem standard for background levels of radiation.
from the surface and mark on a diagram of the vehicle where the unit registers levels of radiation above background levels.
The scope of services shall include: acquisition, loading, transport and disposal of excavation, tunnel excavation with geogenic background levels from the PFA 1.
London, Oct 21 ( ANI ): When in Rome, you get a little hit of cocaine with every breath, as a study of psychotropic drug levels in ambient air from eight Italian cities found background levels of cocaine, cannabinoids - the active ingredients in marijuana - nicotine and caffeine in every urban centre.
This may seem very low but considering the background levels are extremely low and the resolution of the detector very high most of the counts collected are very meaningful.
Those with higher background levels of dioxin had a greater risk for diabetes," says Dr.
The researchers report that flasks containing deuterated acetone show significant excess of such events compared with background levels, but flasks of ordinary acetone didn't.
write: "While these (air concentrations) were substantially elevated above typical background for the early days, they only occasionally exceeded health benchmarks after the first few weeks, and they had returned to typical background levels by November and December 2001.

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