Effect of airflow interaction in the breathing zone on exposure to bio-effluents

The influence of the complex interaction of three airflows-breathing flow, convective flow around the human body and ventilation flow directed against the face-on the exposure to dermally-emitted effluents from a person's own body was examined together with the effects of source location and control. A breathing thermal manikin was used to simulate a seated person in a full size climate chamber. Bioeffluents released at the armpits and groin were simulated with two tracer gases. It was found that the flow of exhalation substantially affected the exposure to dermally-emitted bio-effluents released close to the breathing flow, e.g. armpits. The exposure in the case of exhalation through the nose was higher than when exhalation took place through the mouth. Breathing did not influence the exposure to gaseous pollutants emitted from the lower part of the body, in this case, the groin. Local pollution source control by exhaust ventilation integrated into the seat reduced the exposure. Airflow imposed against the face can substantially reduce the exposure regardless of the pollution source location. However, when this flow is combined with local source control the exposure may paradoxically increase, depending on the airflow interaction at the breathing zone and the source location. (C) 2017 Elsevier Ltd. All rights reserved.