Characteristics of human bioeffluents “common core” quantity varying with occupant density in indoor respiratory region

In addition to carbon dioxide, human bioeffluents are emitted during the occupant metabolism process. Human bioeffluents should be chosen to provide the comprehensive indication of indoor air pollution caused by occupant metabolism. The relationship between the “common core” quantity of human bioeffluents in the respiratory region and indoor occupant density was studied. The possibility and reliability of the common core for indicating indoor occupant number variation and indoor air pollution induced by occupant metabolism were evaluated. The results comfirm the existence of the common core in human bioeffluents, including 13 chemical constituents emerging under 3 types of occupant densities. However, the quantity of common core in the respiratory region does not strictly follow with the variation of occupant density. Therefore, it cannot provide an effective indication of indoor air pollution affected by occupant metabolism. Further studies are needed to determine the fundamental mechanisms leading the common core quantity to change and fluctuate.