Protocol for the Derivation of Environmental and Human ... - CCME

Mutagenicity: The ability of a chemical to produce a permanent change
in the genetic material.
NNN
N-fixation: The conversion of elemental nitrogen (N 2 ) to organic
combinations or to forms readily usuable in biological
processes.
Negligible risk: Risk that is considered negligible if the estimated
carcinogenic potential of the contaminant in the soil is very small
compared to exposure risks from other media (i.e., air, water,
food).
Nitrification: The biological oxidation of ammonium to nitrate.
NO(A)EL {No observed (adverse) effect level}: The highest dose in a
bioassay with no observed effects in the exposed organisms. In
some cases, observed effects may be of questionable impact or
may possibly be beneficial. Therefore, obvious negative effects
may be differentiated as "adverse".
NOEC (No Observed Effect Concentration): The highest
concentration of a contaminant used in a toxicity test that has no
statistically significant adverse effect on the exposed population
of test organisms relative to a control.
OOO
Objective: A numerical limit or narrative statement that has been
established to protect and maintain a specified use of soil at a
particular site by taking into account site-specific conditions.
PPP
pH: A measure of acidity -- technically, the negative logarithm of
hydrogen ion activity.
Porosity: The volume proportion of the total bulk not occupied by solid
particles.
Probability: The likelihood or frequency of occurrence of an adverse
health effect.
RRR
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