Fig. 4

Representative SEM images showing ultra-structures of disutilized floor samples actually used for each of the hospital floors. Scale bars show 100 μm (low magnification) and 5 μm (high magnification), respectively. All samples consisting of vinyl chloride (‘Hospital B’ also with antibacterial materials) are disutilized floor materials. Samples ‘Hospital A, Hospital C’ and ‘Hospital B’ are provided by TOLI Corporation and TAJIMA ROOFINF, respectively