Zhang, Wei (2014-12). A Study of Dust Movement through Construction Barriers. Master's Thesis.
Airborne infection agents can and do infect patients who have a lung disease or who are coping with a weakened immune systems or in some circumstances otherwise apparently healthy people. A rise in the rate of fungal infection for a particular class of immunosuppressed patients occurred in the last few decades as the medical system improved treatment and reduced mortality rates for a number of common and previously fatal medical conditions. Fungal infection agents are opportunistic and ubiquitous. Fungal infection agents potentially derive from three sources in a hospital setting, from the air handling system, from any construction activity and from the normal hospital operations. These sources were termed Source S-AH, Source S-CA and Source S-NO for this research work respectively. Source S-AH and S-NO are always present in the hospital setting, Source S-CA requires construction activity in or near the hospital. This research work studies the movement of dust particles that can transport Aspergillus spore. Previous research demonstrated that a well-constructed barrier could stop the movement of dust particles from a contaminated to a non-contaminated side. However, it is not practical to completely isolate construction activity in a hospital setting from a patient cohort; the practical step is to reduce the incidence of spore movement on dust through openings in the construction barriers. This research studies the movement characteristics of dust through an opening in a construction barrier in a test rig that models a construction site in a laboratory setting. The results demonstrate movement of the dust occurs with the provision of an opening in a plastic construction wall. The filter collection system analysis showed that the distribution of the dust did not follow a uniform pattern but showed concentrations in a few locations on the filter. The location on the filter directly beneath the door showed a five-fold total concentration when compared to an area beneath the recirculating fan inlet. The conclusion reached is the airflow direction coupled with random Brownian motion impacts on the concentration of dust particles. The hypothesis is false. Future research should be directed at understanding the physical issues of the dust movement in a room setting and developing a finite element model of the test arrangement.