The action or process of accumulating, state of being or having accumulated, a collecting together.
(Science: pharmacology) Repeated exposures to a chemical or drug may result in the progressive increase of its concentration in an organism, organ or tissue. Illness or other effects may increase with successive doses.
factors involved in accumulation include selective binding of the drug to tissue molecules, concentration of fat soluble drugs in body fat, absent or slow metabolism of the drug, and slow excretion of the drug.
accumulation is a mass balance effect where input exceeds output.