Risk Exposure to Particles – including Legionella pneumophila – emitted during Showering with Water-Saving Showers

The increase in legionellosis incidence in the general population in recent years calls for a better characterization of the sources of infection, such as showering. Water-efficient shower systems that use water atomization technology may emit slightly more inhalable bacteria-sized particles than traditional systems, which may increase the risk of users inhaling contaminants associated with these water droplets. To evaluate the risk, the number and mass of inhalable water droplets emitted by twelve showerheads—eight using water-atomization technology and four using continuous-flow technology— were monitored in a shower stall. The water-atomizing showers tested not only had lower flow rates, but also larger spray angles, less nozzles, and larger nozzle diameters than those of the continuous-flow showerheads. A difference in the behavior of inhalable water droplets between the two technologies was observed, both unobstructed or in the presence of a mannequin. The evaporation of inhalable water droplets emitted by the water-atomization showers favored a homogenous distribution in the shower stall. In the presence of the mannequin, the number and mass of inhalable droplets increased for the continuous-flow showerheads and decreased for the water-atomization showerheads. The water-atomization showerheads emitted less inhalable water mass than the continuous-flow showerheads did per unit of time; however, they generally emitted a slightly higher number of inhalable droplets—only one model performed as well as the continuous-flow showerheads in this regard. To specifically assess the aerosolisation rate of bacteria, in particular of the opportunistic water pathogen Legionella pneumophila, during showering controlled experiments were run with one atomization showerhead and one continuous-flow, first inside a glove box, second inside a shower stall. The bioaerosols were sampled with a Coriolis® air sampler and the total number of viable (cultivable and noncultivable) bacteria was determined by flow cytometry and culture. We found that the rate of viable and cultivable Legionella aerosolized from the water jet was similar between the two showerheads: the viable fraction represents 0.02% of the overall bacteria present in water, while the cultivable fraction corresponds to only 0.0005%. The two showerhead models emitted a similar ratio of airborne Legionella viable and cultivable per volume of water used. Similar results were obtained with naturally contaminated hoses tested in shower stall. Therefore, the risk of exposure to Legionella is not expected to increase significantly with the new generation of water-efficient showerheads

Indoor Air Quality: From Sampling to Risk Assessment in the Light of New Legislations

This Special Issue aims to make a concrete technical contribution to the solution of the various problems related to indoor air pollution. In 11 papers, international scientists report the last findings in this field from different points of view including topics such as the IAQ legislation, the role of IAQ in schools, hospitals and (micro)environments in general, the performance of an olfactometer system or the impact of an indoor malodor, BTEX measures in a Fire Station, and a chemical characterization of e-cigarette (e-cig) refill liquids (e-liq). It seems appropriate to encourage the development of reference values or specific action values in order to better manage particularly problematic situations in these environments. In the absence of national references to be used for a comparison, it is possible to use those reported in the legislation of other European countries or, by ad hoc working groups or by analogy, to use other standards such as those relating to ambient air

Full Proceedings, 2018

Full conference proceedings for the 2018 International Building Physics Association Conference hosted at Syracuse University

Indoor Environment Quality and Health in Energy-Efficient Buildings

This Special Issue addresses a topic that is of great relevance as, nowadays, in developed countries, individuals spend most of their time indoors and, depending on each person, the presence at home ranges between 60% and 90% of the day, with 30% of that time spent sleeping. Considering these data, indoor residential environments have a direct influence on human health, especially considering that, in developing countries, significant levels of indoor pollution make housing unsafe, having an impact on the health of inhabitants. Therefore, housing is a key health factor for people all over the world, and various parameters, such as air quality, ventilation, hygrothermal comfort, lighting, physical environment, and building efficiency, can contribute to healthy architecture, as well as to the conditions that can result from the poor application of these parameters. The articles in this Special Issue thus address issues concerning indoor environmental quality (IEQ), which is described, more simply, as the conditions inside a building. This includes air quality, but also access to daylight and views, pleasant acoustic conditions, and occupant control over lighting and thermal comfort. IEQ also includes the functional aspects of the space, such as whether the layout provides easy access to tools and people when needed and whether there is sufficient space for the occupants. Building managers and operators can increase building occupant satisfaction by considering all aspects of IEQ rather than focusing on temperature or air quality alone

The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology