| 1. |
- Romano, Francesco, et al.
(author)
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Dispersal chambers used for evaluation of cleanroom and surgical clothing systems - examples of performed tests and results
- 2016
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In: International Symposium on Contamination Control, ICCCS, Sao Paulo, Brazil sept 2016.
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Conference paper (peer-reviewed)abstract
- Chalmers University of Technology in Sweden and Politecnico di Milano in Italy have developed and installed two experimental dispersal chambers (body-box) for the measurement of the rate of total and microbial airborne particle dispersion from persons (wearing technical clothing system) and from equipment in cleanrooms and in Operating Theaters (OT). This paper describes the two dispersal chambers and the adopted test procedures for person particle dispersion tests. The release rate of total airborne particles (in defined particle size ranges) emitted from a person and his gowning system while performing standard movements and the release rate of aerobic Colony Forming Unit (CFU) of the same person and gowning system, can be considered as the personnel source strenght, a fundamental parameter both in design and in operation of a clean space. Moreover, the personnel source strength data could be used in order to compare technical clothing systems in terms of their particle shedding, and even more interestingly in terms of their ability to filter and to limit the personnel airborne particler release. The study presents data obtained in experimental compaigns made in the two labs. The results of the experimental tests carried out on different technical clothing systems are discussed and compared, highlighting the effect on emission rates of the garment type and of the number of undergone cycles of Washing, Drying and Sterilization (WDS). The source strenght data presented in this paper can be used in the design phase of cleanrooms and of OT to size the total air flow required for contamination control and to forecast the concentrations of aerobic CFUs and total airborne particles.
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| 2. |
- Romano, Francesco, et al.
(author)
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Electrosurgical Smoke: Ultrafine Particle Measurements and Work Environment Quality in Different Operating Theatres
- 2017
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In: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 14:2, s. 137-
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Journal article (peer-reviewed)abstract
- Air cleanliness in operating theatres (OTs) is an important factor for preserving the health of both the patient and the medical staff. Particle contamination in OTs depends mainly on the surgery process, ventilation principle, personnel clothing systems and working routines. In many open surgical operations, electrosurgical tools (ESTs) are used for tissue cauterization. ESTs generate a significant airborne contamination, as surgical smoke. Surgical smoke is a work environment quality problem. Ordinary surgical masks and OT ventilation systems are inadequate to control this problem. This research work is based on numerous monitoring campaigns of ultrafine particle concentrations in OTs, equipped with upward displacement ventilation or with a downward unidirectional airflow system. Measurements performed during ten real surgeries highlight that the use of ESTs generates a quite sharp and relevant increase of particle concentration in the surgical area as well within the entire OT area. The measured contamination level in the OTs are linked to surgical operation, ventilation principle, and ESTs used. A better knowledge of airborne contamination is crucial for limiting the personnel’s exposure to surgical smoke. Research results highlight that downward unidirectional OTs can give better conditions for adequate ventilation and contaminant removal performances than OTs equipped with upward displacement ventilation systems.
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| 3. |
- Romano, Francesco, et al.
(author)
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Numerical and experimental analysis of airborne particles control in an operating theater
- 2015
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In: Building and Environment. - : Elsevier BV. - 0360-1323. ; 89, s. 369-379
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Journal article (peer-reviewed)abstract
- The design of a ventilation system for operating theaters (OT) is aimed to reduce the patient infection risk while maintaining adequate comfort and productivity for the surgical staff. Nowadays, Computational Fluid Dynamics (CFD) represents an important tool to simulate the airflow pattern in an operating theater and its ability to remove airborne particles. The CFD advantages, compared to experimental campaigns, consist in the ability to test different configurations, in the ease of implementation and in time and money savings. The aim of this work is to numerically and experimentally investigate an OT with a layout according to the Standard DIN 1946-4. Moreover the effectiveness of a differential airflow diffusion system on reducing the particle concentration above the operating table is analyzed. The supply air comes from a ceiling filter system composed of 23 H14 filters, which assures an unidirectional flow with differential air velocities over the protected area. In order to experimentally evaluate the performance and the protection grade SG, according to DIN 1946-4, and to validate the numerical results, a measuring campaign has been carried out within a laboratory setup of an OT. Two different scenarios have been adopted to evaluate the protection level against the entry of external and internal contaminant loads into the protected area. For both cases, the simulated and measured particle concentration in the protected area agree well, and the differential air flow diffusion system is able to maintain the desired protective effect (SG) against contamination load in both the design and the off-design conditions.
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| 4. |
- Romano, Francesco, et al.
(author)
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Performance test of technical cleanroom clothing systems
- 2016
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In: Proceedings of Indoor Air 2016, 14 th International Conference on Indoor Air Quality and Climate, paer#990, Ghent, Belgium, 2016.
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Conference paper (peer-reviewed)abstract
- The work presented in this paper deals with aseptic cleanroom clothing systems performance and gowning procedures. The study had the purpose of evaluating the inert and viable airborne particle concentration shed by personnel when gowning a complete cleanroom clothing system suitable for aseptic operations at different washing, drying, sterilization (WDS) cycles. The tests procedure consisted of a normal working activity carried out in a stainless steel body box test rig. Inert and viable airborne contamination has been monitored continuously and in parallel throughout all experimental test following aseptic procedures during the sampling task. Results have shown how WDS cycles, clothing size and personnel activity may influence the particle content shed by personnel and therefore the air cleanliness of an environment. Personnel working in clean environments might be aware of the importance of gowning system clothing and their procedures as well as the importance of training in operational behaviors in aseptic environments.
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| 5. |
- Romano, Francesco, et al.
(author)
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Some aspects on the sampling efficiency of microbial impaction air samplers
- 2015
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In: Particuology. - : Elsevier BV. - 2210-4291 .- 1674-2001. ; 20, s. 110-113
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Journal article (peer-reviewed)abstract
- Indoor microbial monitoring is an important health issue in many sectors of society. In particular, it is important to monitor microbial concentrations in environments dealing with bio-susceptible products. Many human diseases are related to high, undesired microbial airborne concentrations. However, the lack of a standardized and well-accepted methodology for testing and ranking the performance of microbial air samplers is a source of uncertainty in such measurements. Several works clearly show that results obtained from microbial air sampling depend largely on measuring techniques, especially the air samplers' physical parameters, such as d(50), as well as environmental conditions, sources, and concentrations of microbial organisms in the environment. Furthermore, personnel using cleanroom clothing can reduce the microbial burden within a clean environment. To evaluate this effect, we carried out experimental comparison tests in a cleanroom of class ISO 5 with different air samplers under various microbial concentration levels, generated by a human source dressed in different quality cleanroom clothing. Our results confirm that in addition to the measuring technique, cleanroom clothing does influence microbial contamination, affecting air sampler measurements.
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| 6. |
- Romano, Francesco, et al.
(author)
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Surgical Smoke and Airborne Microbial Contamination in Operating Theatres: Influence of Ventilation and Surgical Phases
- 2020
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In: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 17:15, s. 1-13
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Journal article (peer-reviewed)abstract
- Air cleanliness is a crucial factor in operating theatres (OTs), where the health of patients and staff must be preserved by controlling air contamination. Particular attention must be paid to ultrafine particles (UFPs) size range, generated for instance by electrosurgical instruments (ESTs). OT contamination is also affected by ventilation systems, medical staff and their gowning system, staff routines, instruments, etc. This comparative study is based on experimental measurements of airborne microbial contamination and UFPs carried out during real ongoing surgeries in two OTs equipped with upward displacement ventilation (UWD) and hybrid ventilation, with unidirectional airflow on the operating table and peripheral mixing (UDAF+Mixing) ventilation systems. Airborne contamination concentration at the exit grilles has been analyzed as function of four different surgical phases normally performed during an operation. Results highlight that airborne contamination is influenced by the activities carried out during the surgical phases. EST usage affects the contamination level more than staff size during operation observed. Colony forming unit (CFU) values in the protected area close to the patient's wound are influenced more by the type of ventilation system than by surgical phases. CFU values decrease by 18 to 50 times from the UWD system to the hybrid one. The large airflow volumes supply together with high air velocities in OTs equipped with UDAF+Mixing systems guarantee a better and a safer airborne contamination control for patients and medical team in comparison with UWD systems.
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