Population at risk

Population at Risk
A population subgroup that is more likely to be exposed to a chemical, or is more sensitive to the chemical, than is the general population.
Porosity ...

incidence rate A measure of the frequency with which an event, such as a new case of illness, occurs in a population over a period of time. The denominator is the population at risk; ...

Total number of individuals who have an attribute or disease at a particular time (or during a particular period) divided by the population at risk of having the attribute or disease at this point in time or midway through the period.

See also: Site, Organism, Inhalation, Toxic, Radiation