Aggravated exposure risks of children to multipath transmitted pathogens in indoor environments

Considering the significance of multipath transmissions of respiratory pathogens in the post-epidemic era, surprisingly little is acknowledged regarding the susceptibility, short-term aerodynamics, and exposure risk of children in indoor environments. Here, experimental and computational investigations were conducted to evaluate the exposure risks associated with respiratory pathogens. The dominant effect of recirculation structure originating from indoor ventilation, including air supply modes and air change rate, on aerosol dispersion was quantitatively proved. A large proportion of deposited aerosol particles was captured by the human body, and deposited particles may further increase under high air change rate, which required a balanced ventilation strategy. Little discrepancies existed between adults and children in exposure risk by airborne transmission. The infection probability by contact transmission for children, however, may be surprisingly high due to high frequency in interactive activities, deposition on upper and lower limbs of accompanying parents, and the wall within arm span.