Quantitative and Qualitative Research of Surface Bacteria on the Floor of Station Restrooms with Two Types of Cleaning Method

Abstract

There are two types of method for cleaning station restrooms. One method uses water for cleaning floors, whereas the second does not. This study describes quantitative and qualitative research into the sur face bacteria found on station restroom floors where these two cleaning methods were used. Samples for analysis were collected from five positions on the floor of each restroom in each railway station investigated. Samples were treated using a conventional culture method to measure the concentrations of surface bacteria on each restroom floor. Samples were then analyzed with bacterial 16S rRNA genes to analysis the microbi omes on these restroom floors. Results showed that the restrooms cleaned without water had lower concen trations of bacteria, than the microbiomes from restroom floors cleaned with water. A and C in October 2018, January and July 2019, and in Stations B and D in July 2019. At Stations A and C, a qualitative investigation was conducted during the daytime (during business hours) on January 8, 2019 (Table 2). The temperature and humidity recorded at the time of the investigation are listed in the same table. Each of the 5 sampling positions were investigated qualitative-ly and quantitatively: under washbasins, under urinals, between urinals, and the central and back corners of the floor, in each station. Bacteria was collected from floors using one of two possible methods. The first method used a 10-cm square frame, which was Earth retaining structures, such as bridge abutments and retaining walls, are con-structed at the boundary of bridges or embankments. There are a variety of earth retaining structure failure modes, therefore in order to be able to ensure rational aseismic reinforcement, it is necessary to develop a range of different aseismic reinforcement methods adapted to the relevant earth retaining structure’s failure mode. Moreover, there are many cases where construction work is severely restricted due to various limitations, such as land boundaries, available space, and time available for construction work. Therefore, the authors propose an aseismic reinforcement method, which can both improve seismic performance of earth retaining structures and be carried out efficiently. This paper outlines this research and describes some examples of the practical application of the newly developed reinforcement method.