What dangers does the air conditioner hide and how can we prevent them?

According to UN Secretary-General António Guterres, we are heading towards a “climate hell” (Paddison, 2024). It appears that the summer of 2024 will be the hottest on record, according to climatologist Roxana Bojariu (Milea, 2024). Under such conditions, air conditioning becomes a necessity for our comfort. However, it is important to also be aware of the negative effects on our health, especially when the air conditioning unit is not cleaned properly. In this article, we will delve into the dangers hidden by its incorrect maintenance and use.

The importance of properly cleaning the air conditioner

British researchers have revealed that our country is among the most polluted in the world, with indoor spaces being more polluted than outdoor ones (we rank sixth globally for poor indoor air quality). (Dyson, 2022)

Regular maintenance of the air conditioner is extremely important. The humid microclimate inside it is favorable for the development of bacteria, fungi, and spores, and without periodic cleaning, these, along with various allergens, are released into the air, affecting our health. Furthermore, periodic maintenance will lead to higher performance of the device, lower energy consumption, and a longer service life.

By regulating ambient temperature, comfort increases and, consequently, productivity. (Cedeño Laurent et al., 2018) If the device is used during the summer, cleaning it once a year is sufficient, and if it is used year-round, cleaning should be performed every six months or even more often if there is a lot of dust in the area where you live (Lockyer, 2023). As long as it is maintained periodically and correctly, it can function perfectly for up to 15-20 years. (***, 2024)

In the case of car filters, they must be cleaned every 2-3 months and replaced every six months (the first time in spring, before the pollen season, and after that, before the start of winter), according to physician Andreas Winkens. (***, 2023)

The health effects of air conditioning

Correct use of air conditioning, besides improving thermal comfort and productivity (Cedeño Laurent et al., 2021), is beneficial both for people with respiratory conditions, whom it protects from external allergens and pollutants, and for the elderly and those with chronic conditions, whom heat affects significantly.

The WHO warns that spending time in an overheated room can lead to heatstroke, dehydration, and symptoms similar to those of heatstroke and heat exhaustion. High body temperature can cause dizziness, nausea, cramps, fainting sensations, and even a stroke. (***, 2024)

By keeping doors and windows closed and using the air conditioner, the presence of insects indoors can be reduced.

A cooler environment promotes sleep by triggering the body's homeostatic control mechanisms. (Anderson, 2024)

There are also risks when we use the air conditioner incorrectly, excessively, and without having cleaned it properly beforehand.

Air conditioning dries the indoor air, humidity decreases, and if we spend a lot of time in this environment without hydrating, dehydration can occur, accompanied by headaches, fatigue, dry lips and skin, and dizziness (Veazey, 2023).

The aqueous layer of the tear film evaporates faster, leading to dry eyes with itching and discomfort, and without lubrication, the eyes are more vulnerable to inflammation (blepharitis) and infections (viral, bacterial, or fungal conjunctivitis) (***, 2021).

Dryness can also be present in the nose, manifesting as itching, sneezing, bleeding, and crusting.

Skin loses its moisture, becoming dry and irritated. (Ohno et al., 2013)

Sudden temperature changes cause rapid constriction and dilation of blood vessels in the head, leading to the onset of pain. Prolonged exposure to cold and dry air can cause sinus inflammation, exacerbating migraines (Veazey, 2023).

Sudden temperature changes are also the cause of muscle pain and contractures, which can lead to spinal pain. In people who sit directly in the cold airflow, involuntary and persistent contractions in the neck muscles, neuralgia, torticollis, sciatica, or acute lumbago can occur. (Amy Richter, 2021)

Exposure to air conditioning can induce fibromyalgia (***, 2021), characterized by diffuse pain and sensitivity of muscles and soft tissue, Raynaud's syndrome (cold hands and feet syndrome) (***, 2019), and cold dermatitis (***, 2021).

People who spend a long period in a room where the air conditioner is set to a very low temperature tend to become more lethargic. This happens because cold air can lower the metabolic rate, slowing down the body's natural processes. (***, 2018)

In the case of noisy devices, continuous exposure to them can lead to increased stress levels and sleep disorders. (Dutchen, 2022)

People who have prolonged contact with cold and dry air may experience upper respiratory tract symptoms, with particular impact on the nose and throat. (Graudenz et al., 2005)

When air is pulled through the device's system, condensation is produced, and the humidity is ideal for the proliferation of bacteria and mold. Failure to properly clean the device can cause respiratory irritation, even aggravating allergy and asthma symptoms, as various allergens and pollutants (dust, pollen, mold, chemicals in the air, etc.) are released indoors, sometimes even leading to respiratory distress (Brown et al., 2014). Also, viruses, bacteria, bacterial spores, and fungi (Influenza, Coronavirus, Staphylococcus, Legionella pneumophila, Clostridium difficile, Bacillis anthracis, Aspergillus, Penicillium) can enter homes, increasing the risk of respiratory infections. (Ijaz M, B, KE, JR, & SA, 2016)

One such infectious disease is that caused by Legionella pneumophila (legionellosis), a bacterium that survives in the condensed water of the air conditioning system. The disease begins approximately 3-6 days after infection, with the most common symptoms being fever, headaches, muscle aches, chills, and breathing difficulties. If left untreated, it can evolve into acute pneumonia, particularly dangerous for children, the elderly, and smokers (***, 2024).

Another condition that can be triggered by contact with infectious agents (fungi, bacteria, protozoa), proteins of animal and vegetable origin, and organic and inorganic chemicals with low molecular weight is hypersensitivity pneumonitis (HP), formerly called extrinsic allergic alveolitis. Acute infection occurs after a few hours or days of short-term and intermittent antigen exposure, and symptoms begin with fever, cough, dyspnea, asthenia, myalgia, and a general state of malaise. Prevention is the most important way to avoid illness. Continuous exposure to causative antigens leads to the risk of progressive lung damage. (Sforza & Marinou, 2017)

With excessive use of air conditioning, tolerance to heat and humidity decreases and you will face difficulties in adapting to an environment without it. (Ellis, 2023)

In 1984, the WHO conducted a study that presented the extremely poor air quality inside buildings. This led to two categories of conditions: “sick building syndrome” and diseases related to buildings (“building-related illness”). (Edward P. Horvath, 1997)

In the case of “sick building syndrome,” the triggering causes are not yet known, but it is assumed to be related to poor indoor air quality, primarily due to problems with the air conditioning system. Symptoms include muscle pain, irritation of mucous membranes (ocular and oropharyngeal), cough, dry throat sensation, headaches, drowsiness, and severe fatigue. (Ganji, Kalpana, Madhusudhan, Nitin Ashok John, & Taranikanti, 2023)

How can we prevent the side effects of using an air conditioner?

To avoid the dangers of using an air conditioner, it must be properly cleaned and maintained periodically.

Rooms should be aired out before using the device, the temperature should be between 21-25°C (it is recommended to have a temperature 3-5°C lower than the outside temperature), and the airflow should not be directed at the people in the room. (Ministry of the Environment Housing and Building D, 2003)

It is important that the temperature difference is not greater than 8°C when moving from one place to another, and the transition should be gradual. (D’Amato et al., 2018)

Maintain an optimal humidity level in the rooms, between 30-50%, by using a humidifier or a bowl of water near the air conditioner (Thompson, Jachura, & Novak, 2024).

Hydrate yourself using creams and by consuming enough fluids and foods with a high water content.

To clean and properly disinfect the air conditioner, follow the steps indicated in this article and enjoy a cool, safe summer.

Bibliography

***. (2018). Retrieved from https://doctor.ndtv.com: https://doctor.ndtv.com/living-healthy/side-effects-of-air-conditioning-ac-we-should-watch-out-for-1860074

***. (2019). Retrieved from https://health.usnews.com/: https://health.usnews.com/conditions/raynauds-syndrome

***. (2021). Retrieved from https://www.mayoclinic.org/: https://www.mayoclinic.org/diseases-conditions/cold-urticaria/symptoms-causes/syc-20371046

***. (2021). Retrieved from https://www.bostontrials.com/: https://www.bostontrials.com/managing-fibromyalgia-during-the-summer/#!/

***. (2021). Retrieved from https://www.thereportingtoday.com: https://www.thereportingtoday.com/eyes-could-be-affected-by-long-term-use-of-air-conditioners-dr-shahnawaz-hossain/

***. (2023). Retrieved from https://herthundbuss.com/: https://herthundbuss.com/en/industry-more/cabin-filters-this-is-how-often-it-should-really-be-replaced/

***. (2024). Retrieved from https://www.fourseasonsheatingcooling.com/: https://www.fourseasonsheatingcooling.com/blog/4-signs-its-time-to-replace-your-air-conditioner/

***. (2024). Retrieved from https://www.lung.org/.

***. (2024). Retrieved from https://www.who.int: https://www.who.int/news-room/fact-sheets/detail/climate-change-heat-and-health

Amy Richter, R. (2021). Retrieved from https://www.arlingtonairconditioningheating.com: https://www.arlingtonairconditioningheating.com/does-air-conditioner-cause-joint-pain/?utm_content=cmp-true

Anderson, S. (2024). (M. Dr. Jordan Burns DC, Editor) Retrieved from https://zomasleep.com: https://zomasleep.com/blog/sleeping-in-cold-room#:~:text=Cooler%20temperatures%20can%20trigger%20the%20body%20to%20produce,your%20circadian%20rhythms%2C%20ensuring%20more%20consistent%20sleep%20patterns.

Brown, K. S., Minegishi, T. M., Allen, J. D., McCarthy, J. S., Spengler, J. P., & MacIntosh, D. S. (2014). Reducing patients’ exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters. Journal of Asthma, 51(6), 585-594. Retrieved from https://www.tandfonline.com/doi/full/10.3109/02770903.2014.895011

Cedeño Laurent , J., Williams, A., Oulhote, Y., Zanobetti, A., Allen, J., & Spengler, J. (2018). Reduced cognitive function during a heat wave among residents of non-air-conditioned buildings: An observational study of young adults in the summer of 2016. PLOS Medicine.

Cedeño Laurent, J., MacNaughton, P., Jones, E., Young, A., Bliss, M., Flanigan, S., . . . Allen, J. (2021). Associations between acute exposures to PM2.5 and carbon dioxide indoors and cognitive function in office workers: a multicountry longitudinal prospective observational study. Environmental Research Letters, 16.

D’Amato, M., Molino, A., Calabrese, G., Cecchi, L., Annesi-Maesano, I., & D’Amato, G. (2018). The impact of cold on the respiratory tract and its consequences to respiratory health. Clinical and Translational Allergy volume, 8. Retrieved from https://ctajournal.biomedcentral.com/articles/10.1186/s13601-018-0208-9#ref-CR61

Dutchen, S. (2022). Retrieved from https://magazine.hms.harvard.edu: https://magazine.hms.harvard.edu/articles/noise-and-health

Dyson. (2022). Retrieved from https://www.dyson.co.uk/: https://www.dyson.co.uk/discover/news/latest/dyson-connected-data-study

Edward P. Horvath, M. M. (1997). Building-related. CLEVELAND CLINIC JOURNAL OF MEDICINE, 64. Retrieved from https://www.ccjm.org/content/ccjom/64/6/303.full.pdf

Ellis, R. R. (2023). (M. Zilpah Sheikh, Editor) Retrieved from https://www.webmd.com/: https://www.webmd.com/a-to-z-guides/ss/slideshow-what-ac-does-to-your-body

Ganji, V., Kalpana, M., Madhusudhan, U., Nitin Ashok John, & Taranikanti, M. (2023). Impact of Air Conditioners on Sick Building Syndrome, Sickness Absenteeism, and Lung Functions. Indian Journal of Occupational and Environmental Medicine, 27, 26-30. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10257240/

Graudenz, G., Oliveira, C., Tribess, A., Mendes, C., Latorre, M., & Kalil, J. (2005). Association of air-conditioning with respiratory symptoms in office workers in tropical climate. Retrieved from https://pubmed.ncbi.nlm.nih.gov/15660569/

Ijaz M, K., B, Z., KE, W., JR, R., & SA, S. (2016). Generic aspects of the airborne spread of human pathogens indoors and emerging air decontamination technologies. American Journal of Infection Control, 44.

Lockyer, K. (2023). Retrieved from https://www.canstarblue.com.au: https://www.canstarblue.com.au/appliances/how-to-clean-your-airconditioner/

Milea, A. (2024). Retrieved from https://observatornews.ro: https://observatornews.ro/vremea/onu-in-vara-lui-2024-ne-putem-astepta-la-un-iad-climatic-cum-vor-fi-lunile-iulie-si-august-in-romania-579713.html

Ministry of the Environment Housing and Building D. (2003). Retrieved from chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.edilex.fi/data/rakentamismaaraykset/d2e.pdf

Ohno, H., Nishimura, N., Yamada, K., Shimizu, Y., Iwase, S., Sugenoya, J., & Sato, M. (2013). Effects of water nanodroplets on skin moisture and viscoelasticity during air-conditioning. Skin Research and Technology, 19(4), 375-383. Retrieved from https://onlinelibrary.wiley.com/doi/10.1111/srt.12056

Paddison, L. (2024). Retrieved from https://edition.cnn.com/: https://edition.cnn.com/2024/06/05/climate/12-months-record-heat-un-speech/index.html

Sforza, G., & Marinou, A. (2017). Hypersensitivity pneumonitis: a complex lung disease. Clinical and Molecular Allergy: CMA. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28286422/

Thompson, J., Jachura, J., & Novak, L. (2024). Retrieved from https://todayshomeowner.com/: https://todayshomeowner.com/hvac/guide/humidity-level-at-home/#:~:text=According%20to%20the%20U.S.%20Environmental%20Protection%20Agency%20%28EPA%29%2C,%E2%80%94%20and%20must%20be%20kept%20below%2060%25%20RH.

Veazey, K. (2023). (K. Veazey, Ed.) Retrieved from https://www.medicalnewstoday.com/: https://www.medicalnewstoday.com/articles/headache-from-air-conditioner#noise