Option (iii) has the further advantage of making the archive “self-cleansing” (i.e. filings expire after a period of time).

In subsequent years, while self-cleansing of the tree crown has continued, radionuclides of caesium-137 and strontium-90 have increasingly been absorbed by the tree via the roots.

(b) Procurement of 5,200 and 4,000 sets of protective clothing, means of self-defence, and cleansing and disinfecting equipment;

So they (both) went off until, when they (both) met a youth, then he killed him. He said, "Have you killed a most cleansed self without (his having killed another) self? Indeed you have already come with a (highly) maleficent thing."