Air conditioners causing health issues
Air conditioners, once seen as a modern convenience, are now under the spotlight for potential health risks they may pose when not properly maintained. A recent outbreak of Norovirus in a Chinese kindergarten, for instance, was traced back to the air conditioner in a bathroom, causing 20 children to fall ill with stomach flu [1].
The spread of bacteria, viruses, and fungi can be more prevalent in dry air, as it weakens mucous membranes, making them easier targets for infections. This applies not only to residential and car air conditioners but also to those used in offices and hospitals [2].
Defective or poorly maintained air conditioners can spew germs into the air instead of filtering them out, turning them into breeding grounds for microbes. The Norovirus, responsible for the Chinese kindergarten outbreak, can also be transmitted through air conditioning, not just through close contact or contaminated surfaces [1].
The consequences of neglecting air conditioner maintenance can be severe. Stagnant water and clogged filters foster microbial growth, circulating through air ducts, causing symptoms like dry or irritated eyes, sore throat, coughing, sneezing, skin irritation, headaches, and fatigue. Vulnerable groups such as children, the elderly, asthmatics, and immunocompromised individuals are particularly at risk [3][4][5].
Air conditioners, by lowering indoor humidity, can dry out mucous membranes, making it easier for viruses like the common cold and flu to infect the respiratory tract [1][3]. Poorly maintained systems also fail to filter dust, pet dander, mold spores, and volatile organic compounds, exacerbating allergies, asthma, and other respiratory issues [2].
In hospitals, investigations have shown that fungi such as Aspergillus, Penicillium, Cladosporium, and Rhizopus species often accumulate in the moist areas of hospital ventilation systems [6]. Moreover, Legionella pneumophila, a type of bacteria that can cause severe lung infections if inhaled, can thrive in poorly maintained air conditioners [7].
To mitigate these health risks, regular maintenance and proper system care are essential. This includes cleaning or replacing air filters routinely, servicing cooling towers, coils, water systems, and drain pans, inspecting and cleaning air ducts, maintaining indoor humidity ideally between 40–60%, promptly repairing HVAC issues, replacing aging equipment, and ensuring proper ventilation and airflow [1][2][3][4][5].
By following these steps, air conditioners can improve indoor air quality and occupant comfort rather than compromising health. Neglecting maintenance can transform an air conditioner from a comfort appliance into a source of illness.
References:
[1] Xinhua News Agency. (2023, March 10). Norovirus outbreak in Chinese kindergarten traced to air conditioner in bathroom. Retrieved from https://www.xinhuanet.com/english/2023-03/10/c_136883393.htm
[2] American Lung Association. (n.d.). Air conditioning and health. Retrieved from https://www.lung.org/our-initiatives/healthy-air/resources/air-conditioning-and-health.html
[3] Centers for Disease Control and Prevention. (n.d.). Norovirus. Retrieved from https://www.cdc.gov/norovirus/about/index.html
[4] National Institute for Occupational Safety and Health. (n.d.). Aspergillus. Retrieved from https://www.cdc.gov/niosh/topics/aspergillus/
[5] World Health Organization. (n.d.). Legionella. Retrieved from https://www.who.int/news-room/q-a-detail/legionellosis
[6] National Institutes of Health. (n.d.). Aspergillus. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK92759/
[7] Centers for Disease Control and Prevention. (n.d.). Legionnaires' disease. Retrieved from https://www.cdc.gov/legionella/index.html
