The main floors at major hospitals in Korea ― usually filled with visitors, patients and staff throughout the day ― are generally contaminated with airborne bacteria that could cause a secondary infection in people with a weak immune system, a report showed Monday.

“The average levels of bacteria, gram-negative bacteria and fungi indicated that all hospital lobbies were generally contaminated,” said the report’s coauthor Park Dong-uk, an environmental health professor at Korea National Open University.

Park and his team assessed the level of airborne bacteria, gram-negative bacteria and fungi in six hospital lobbies ― four general hospitals in Seoul and two others in Gyeonggi Province ― and investigated the environmental characteristics that affected the airborne microorganism levels.

The level of contamination was highest during the summer and relatively lower in winter.

Bacteria levels peaked in summer, at 970 per 1,000 cubic liters of air in the summer, surpassing the air pollution standard level of 800 set by the Ministry of Environment.

An average of 720 bacteria per 1,000 cubic liters of air was found in the six hospital lobbies, close to the 800 level that indicates indoor air pollution.

The study also showed that the airborne bacteria contained a high level of gram-negative bacteria, which have impenetrable cell walls that make them more resistant to antibodies. Such bacteria include salmonella and dysentery bacillus which can cause pneumonia or urinary tract infections in people with extremely weak immune systems.

Park in the report urged hospitals to check their central air conditioning systems and set new safety measures to reduce air contamination and prevent secondary infections, not only in the lobbies but also, most importantly, in operating and emergency rooms and pediatrics wards.

The report was published in a recent edition of the International Journal of Environmental Research and Public Health.

By Cho Chung-un (christory@heraldcorp.com)