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.
That is, any (detectable) background level in the assay will be suppressed when a repellant is present therein.
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
9) we have a single expression for the observed profile in terms of the crystallite size distribution and shape, background level, and statistics of the experiment; information concerning the crystallite properties has been incorporated.
The number of pulses, he added, seems to surge about two weeks before the earthquake then drop back to background level until shortly before the fault slips.
EPA officials conducted tests last May and found radiation levels inside the warehouse were 100 times higher than background levels, while a yard had 10 times the background level.
But experts such as Professor Tucker have been tasked with bringing the level of aircraft noise down to around 55 decibels, the average background level of noise.
In addition, continuously updated digital readings are presented for the local background level of methane along with the most recent maximum reading from a previously detected leak.
This suggests atmospheric reactions may create a low background level of perchlorate.
When the body isn't under assault, however, CLA appears to dampen down the natural background level of immune stimulation.
One area with a scintillation count as high as 250 times the background level was found on as yet unexplored ground.
Study author Joseph Kiesecker says that during the trials, all tanks had active airstones that would have made it highly unlikely that any sound produced by the tadpoles could have exceeded the background level.

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