The vatican archives maintain a vault where century's worth of old documents are stored in very high n2 levels to prevent oxidation of the papyrus. when you do research in the vault how does this affect the amount of o2 in your body?

The Vatican archives stores multiple precious documents and books of the world. These old documents dating hundred of years are kept in high nitrogen levels, in order to prevent the oxidation of the paper (papyrus). The presence of the high level of inert nitrogen in the air in the archives prevents any kind of damage that may caused to the paper or the ink on those documents. This high level of nitrogen, however, may affect the health of the individual by decreasing the oxygen levels in the body.

Hence, the answer is 'the oxygen level will be decreased in the body'.

substitution is the answer in this case

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