A recent study carried out by the University of Hong Kong revealed that each subway line in the city has its own bacteria but riders mix them and carry them across the entire subway system. Similar studies conducted in Boston and New York City also revealed that bacteria in the subway are taken through the whole network by travelers.
For this research, the researchers at the University of Hong Kong asked volunteers to clean up their hands and take the subway for 30 minutes. They were asked to hold on the handrails and bars in the train.
Afterward, the volunteers’ hands were swabbed by Gianni Panagiotou and his team, in order to analyze the bacteria proliferating in the Hong Kong subway.
The study aimed to show how many organisms are proliferating in the subway network and if some harmful bacteria or fungi in the subway can threaten the health of the riders.
Bacteria in the subway are carried by riders from one subway line to another
After analyzing the samples, the research team led by Gianni Panagiotou discovered that the most prominent bacteria in the subway are skin bacteria. Also, the most prominent non-bacterial organism is a sort of yeast.
Interestingly, according to the study, the community of microbes decreased over the day from over 140 species found in the morning to about 50 in the evening, the researchers linking this pattern to the morning rush hour and the increasingly lower number of riders in the evening.
Two similar studies yielded the same outcomes in Boston and New York City.
“These studies are the first maps of their kind, and what is striking is the ubiquity of these antimicrobial-resistant genes we see around the world, but also that each city is unique,” asserted Chris Mason at Cornell University, who participated in the New York City study on bacteria in the subway. “We don’t yet know which ones are the most significant for human health,” he added.