Introduction
The past years witnessed an unprecedented increase in practical and theoretical knowledge in various fields of human activity. Much has been learned and discovered about the way human endeavors impact the nature and environment. New advances in sciences have opened new venues for the analysis of the most traditional human decisions. The rapid proliferation of infectious diseases has become one of the central objects of scientific research. Today’s health professionals have numerous infectious disease control measures, which include modifying environmental reservoirs, interrupting transmissions, and protecting the host. Factors that contribute to the development and spreading of infections are numerous, including microbiologic agents and direct/indirect transmission. Nevertheless, the current knowledge of infectious diseases and the patterns of generation and transmission remain largely underresearched. With the growing sophistication of science and medicine, professionals need a better understanding of the way the biological processes in toilets are related to the generation and spreading of infectious diseases. The most important is the analysis of bioaerosol generation during toilet flushing.
What is Known and Not Known about Bioaerosol Generation
Bioaerosol generation and release have always been one of the major causes of public health concerns, mainly because of the impacts it can potentially have on residents (Sanchez-Monedero, Stentiford, & Urpilainen, 2005). Even the most traditional operations taking place in toilet chambers and other bioaerosol generation sites, e.g. composting plants, can readily become the sources of major negative impacts on individual and, consequently, public health (Sanchez-Monedero et al., 2005). Viruses are, probably, the most common cause of infectious diseases, and toilets are believed to play not the last role in the way human viruses and infectious diseases are transmitted (Morawska, 2005). The degree of the biological hazard created by toilets also depends on a number of factors, such as the type of virus, its causes and health effects, concentration levels, and the physical characteristics of the environment (Morawska, 2005). Types of bioaerosols generated in toilet chambers include various microorganisms and constituents that are released at various stages of the toilet use (Morawska, 2005). However, the most problematic is the process of toilet flushing, which is believed to be the source of major biological and infectious controversies in toilet chambers.
Among other indoor chambers, toilets are, probably, the most essential sources of bioaerosols (Anonymous, 2005). “The potential risks associated with toilet plume aerosols produced by flush toilets is a subject of continuing study” (Johnson, Mead, Lynch, & Hirst, 2012). According to Johnson et al. (2012), flushing generates substantial quantities of bioaerosols. Moreover, aerosolization is a continued process that does not stop with the subsequent flushes; consequently, subsequent toilet users can be exposed to various health risks (Johnson et al., 2012). Unfortunately, the study by Johnson et al. (2012) is the only relevant source of scientific knowledge about toilet flushing and its relation to bioaerosol generation. Moreover, Johnson et al. (2012) did not conduct any laboratory experiments, meaning that the results of their review can be biased. Actually, according to Morawska (2005), the relative importance of various transmission mechanisms in bioaerosol generation remains one of the most problematic questions facing present-day science. Therefore, the main questions to be answered in the proposed study are: (1) how are bioaerosols generated during toilet flushing?; and (2) how can bioaerosol generation be effectively controlled?
Methods and Materials
The study will be conducted in two stages. At the first stage of the analysis, the primary goal is to confirm that bioaerosols are generated when toilets are flushed. At this stage of the study, bioaerosols generated from a flushing toilet will be measured. Home toilet chambers will be used to conduct the analysis. A HEPA filter will be used to drive down the background level of airborne particles. The TSI Aerodynamic Particle Sizer (APS) monitor will help measure the particle generation associated with and without the toilet flush three times each. Afterwards, the air filter chamber will be mounted on the top of the rim of the toilet bowl. A gasket on the bottom of the chamber will be used to seal to the porcelain due to the weight of the chamber.
This way, background particles in the chamber will be minimized. With the help of the TSI APS monitor, the number of particles will be measured again, in 10-second intervals for 10 minutes with and without the flush. Each experiment will take place three times. The procedure will be repeated using the toilet bowl with 5 μm polystyrene beads. The schematic of the chamber is provided above.
Data Analysis
The process of collecting the primary data will be followed by its statistical analysis. The goal of the analysis is to confirm (or rule out) the assumption that toilet flushing is the major source of bioaerosols. SPSS software will be used to analyze the changes in bioaerosol concentrations across the toilet chambers before and after flushing. Descriptive statistics will help to evaluate the changes in the concentration of bioaerosols and their relation to toilet flushing.
Possible Limitations
The fact that the study will be conducted only in one home setting suggests that the generalizability of these results can be limited. Moreover, the mere fact that toilet flushing is associated with the generation of bioaerosols does not provide any meaningful information as to the way bioaerosol generation in toilet chambers can be controlled. Actually, the fact that toilet flushing results in bioaerosol generation was confirmed by Johnson et al. (2012), and the proposed study is intended to confirm or refute these results. The proposed study does not seek to resolve the controversies surrounding the possible transmission of infections from one user to another. The infectious transmission potentials of bioaerosols generated during toilet flushing will require further analysis. Johnson et al. (2012) claim that, although aerosolization and toilet flushing accompany one another, no study has clearly demonstrated that aerosolization also contributes to infectious disease transmission.
Conclusion
Toilet flushing is claimed to be one of the major sources of bioaerosols which, in turn, can have potentially negative impacts on individual and public health. The goal of this study is to analyze whether toilet flushing results in bioaerosol generation and how this process can be controlled. The study will take place in home toilet chambers and involve the statistical analysis of the primary data. The need for the experiment is justified by the lack of the empirical data supporting the relationship between toilet flushing and bioaerosol generation. The results of the experiment will add to the current knowledge of bioaerosol generation and expand the existing opportunities to control the spreading of infectious diseases through aerosolization and toilet flushing.
References
Anonymous. (2005). Sensor systems for biological agent attacks: Protecting buildings and military bases. National Academies Press.
Johnson, D.L., Mead, K.R., Lynch, R.A. & Hirst, D.V. (2012). Lifting the lid on toilet plume aerosol: A literature review with suggestions for future research. American Journal of Infection Control. Article in press.
Morawska, Lidia (2005) Droplet fate in indoor environments, or can we prevent the spread of infection? In: Proceedings of Indoor Air 2005: The 10th International Conference on Indoor Air Quality and Climate, 4-9 September, Beijing.
Sanchez-Monedero, M.A., Stentiford, E.I. & Urpilainen, S.T. (2005). Bioaerosol generation at large-scale green waste composting plants. Journal of Air & Waste Management, 55, 612-618.