Holding onto an escalator handrail is a sensible safety measure that tests show can cause risks to users’ health.
So said the results of a test commissioned by Apple Daily, who used the Hong Kong Standards and Testing Centre to undertake a cleanliness test on handrails in four shopping malls and four MTR stations in the city on 14 and 15 August.
Results of the tests showed that after touching escalator handrails the total bacterial count on a person’s hands can be as much as 70 times higher than before, Apple Daily reported.
A colony-forming unit, or CFU, is used in microbiology to measure the number of bacteria or fungal cells in a sample. Prior to collecting data in this exercise reporters disinfected their hands, meaning their hands registered fewer than 10 CFUs.
Test results showed that escalator handrails registered 700 CFU at the Sha Tin MTR station in the New Territories, and 680 CFU were detected on handrails at the APM shopping mall in Kowloon’s Kwun Tong.
New Town Plaza, a shopping mall in Sha Tin recorded 460 CFU while the five other locations tested, including Mong Kok MTR station, Causeway Bay MTR station, Times Square mall in Causeway Bay, Langham Place in Mong Kok and Kwun Tong MTR station recorded readings of between 75 and 95 CFU.
Dr Cheng Chi-man said that bacteria on handrails could include cocci from the intestine, which can cause gastroenteritis if people do not wash their hands properly before eating.
Bacteria picked up in such a way could easily be transmitted to personal belongings, including a mobile phone or tablet. Dr Cheng advised people not to touch their mouth, nose or eyes after making contact with handrails that other people frequently come into contact with.
The MTR Corp said in a statement that it cleaned stations and train compartments regularly. The spokespersons from APM shopping mall and New Town Plaza said they clean and disinfect escalator handrails every day but would increase the frequency when it was necessary.
The report appears incomplete or rather misleading. No biologically free air exists. Human being themselves shed millions of squame or microbial carrying particles. Although some of the microbes are are indeed harmful to human, a host of them are useful for our day-to-day living. That’s the reason why many indoor air quality standards and/Or guidelines provides threshold limits for microbial intensity. For instance, ICOP (2010) specifies 500 cfu/m3 and 1000 cfu/m3 as respective thresholds for bacteria and fungi. Further, excess of microbial counts over the thresholds *"…does not necessarily imply health risk but serve as an indicator for further investigation."*
Hence the reported findings is insufficient to imply an health risk without the identification of the microbial species.