SICK BUILDING SYNDROME: SIGNS, CAUSES AND SOLUTIONS - BIOLOGY - 2025

The syndrome of the sick building (SEE) designates a set of symptoms that can present a considerable percentage of people who live or work inside buildings. In 1982, the World Health Organization recognized the SEE as an important effect on people's health.

This syndrome occurs when a high concentration of pollutants, such as chemical compounds, particulate matter and microorganisms, occurs due to accumulation and faulty ventilation, without total evacuation and renewal of the internal volume of air in the interior spaces of buildings.

Figure 1. Allergies, rhinitis, sore throat, eye irritation and other symptoms produced by the contamination inside the sick building. Source: Pixabay.com

The sick building syndrome is a multifactorial problem, since it is affected by: architectural design, ventilation, engineering related to the type of construction materials and facilities, maintenance and the habits of the occupants of the interior space considered.

Among the habits that generate this syndrome are: inefficient ventilation, use of fossil fuel stoves, heating and water heaters, use of insecticides, cleaning substances aggressive to health, accumulation of dust, composite wood furniture, the smoking habit of the occupants, among others.

Signs for the diagnosis of sick building syndrome

The occupants of a sick building, according to the World Health Organization (WHO), present some or more of the following symptoms:

Respiratory symptoms

• Throat irritation, rhinitis, cough, hoarseness.
• Difficulty breathing; asthma.
• High incidence of respiratory infections and colds.

Eye symptoms

• Irritation of the eyes.

Dermatological symptoms

• Dry skin and mucous membranes, itching.
• Erythemas and skin rashes.

Other varied symptoms with the presence of nonspecific hypersensitivity

• Headaches, nausea, dizziness and vertigo, mental fatigue or exhaustion, lethargy.
• It can also present, exacerbation of pre-existing diseases such as asthma, sinusitis and eczema.

As can be seen, it is a varied and complex symptomatology, as it comes from different effects acting simultaneously on the body.

Causes that generate a sick building

In the interior environments of a sick building, pollutants from the outside air are concentrated. Additionally, other pollutants can be generated within the building. For this reason, poor ventilation favors the problem of sick building syndrome.

The causes that generate sick building syndrome can be grouped into:

Chemical pollutants

Chemical contaminants include:

Carbon monoxide (CO)

In indoor environments the concentration of carbon monoxide (odorless and colorless gas) can increase due to the incomplete burning of domestic gas, charcoal, firewood, kerosene or other carbonated fuel in kitchens, indoor heating and water heaters.

Another cause of increased CO concentration in indoor environments is the habit of “heating up” automobile engines in garages and adjacent parking lots, by igniting for long and unnecessary times.

When carbon monoxide is inhaled through the air we breathe, it passes into the blood where it forms a complex with hemoglobin called carboxyhemoglobin, which is not capable of transporting oxygen to cells.

Exposure to high concentrations of CO causes headaches, fatigue, unconsciousness, and can lead to death. The risk for smokers is much higher since, when inhaling greater amounts of CO during tobacco consumption, they have 3% of their hemoglobin inactive, forming carboxyhemoglobin.

Formaldehyde

Formaldehyde (H ₂ C = O) is a gas of organic origin and one of the most important pollutants in interior spaces. In the outside air it appears in minimal concentrations (trace), since it is a stable intermediate in the oxidation of methane (CH ₄) and volatile organic compounds.

In interior spaces of buildings, formaldehyde concentrations can be considerable due to emissions from cigarette smoke and from industrial materials that contain formaldehyde resins.

These resins are used as an adherent in composite woods, cardboard-wood agglomerates, polyurethane insulating foams, upholstery and carpets.

The formaldehyde used in the production of these objects is released for years in the form of free gas, causing eye, nasal, throat and dermatological irritation, difficulty in breathing, an increase in respiratory diseases, allergies and asthma, even cancer.

Other volatile organic compounds (VOCs)

This group of compounds includes gasoline, kerosene, cleaning solutions, paint solvents, among others, which evaporate easily and are toxic. This group includes insecticides against mosquitoes and crawling insects, which are used in the form of aerosols.

Several research works report a decrease in memory capacity, manual dexterity, color discrimination and visual acuity in factory workers with high levels of VOC concentrations.

Fumes from household cleaners

Household cleaner vapors contain chlorine, sodium hypochlorite, and sodium hydroxide, substances that are highly corrosive and irritating to the respiratory tract.

Nitrogen dioxide

Nitrogen dioxide (NO ₂) concentrations in indoor environments that have kitchens or stoves, water heaters and heating that run on carbonated fuels, are usually higher than those outside. The high temperatures of the flame favor the oxidation of nitrogen in the air to NO ₂.

NO ₂ is a water soluble oxidant and is a chemical precursor of nitric acid, making it an irritant to the human respiratory system. It has been observed that high levels of this gas can affect some sensory processes such as sensitivity to lighting and adaptation to light.

Smoke of the tabacco

Secondhand smoke (HAT) contains thousands of chemical compounds, many of them carcinogenic. Its components include: nicotine, tar, benzene, benzopyrene, toluene, formaldehyde, carbon monoxide, nitrogen dioxide, toxic metals such as lead, cadmium and chromium, among others.

Suspended particles

Suspended particles are a mixture of different solid particles and aerosols suspended in the air. They can be seen as smoke (soot), dust or mist, and are capable of adhering to its surface or dissolving some or all of the other pollutants.

Particles with a diameter less than 10 μm, called PM10, have the greatest impact on human health, since they can be inhaled.

Radon

Radon is the heaviest noble gas; under ambient conditions it is a chemically inert monatomic gas. Radon decays in radioactive sequence into polonium, lead, and bismuth. Polonium (218Po and 214Po) emits radioactive, high-energy α particles that cause cell damage and lung cancer.

The majority source of radon in interior spaces comes from the filtration from the first meter of depth of the soil penetrated by the foundations of the constructions; it enters buildings through cracks in the concrete of the foundation in the basements.

Asbestos

The word asbestos designates six natural silicates with a fibrous structure. Asbestos is used as a thermal insulator, as an aerosol in fire retardant material in buildings and fabrics, an additive to increase the strength of cement in roofs, as a coating for automobile brakes, and in pipes.

The use of asbestos has been reduced as it has been found to be carcinogenic to humans. Thin asbestos fibers easily penetrate lung tissues and cause a special type of lung cancer, after years of exposure.

Biological contaminants

The air in the interior spaces of buildings has been reported to contain microorganisms such as bacteria, fungi, viruses and mites.

The most common bacteria in indoor environments are those belonging to the genera Staphylococcus, Micrococus and Bacillus. Among the most common fungal species are those of the Penicillium, Aspergillus and Cladosporium genera.

On the other hand, mites are tiny arachnids (size between 0.1 to 0.5 mm) of house dust, which feed on human skin scales (dermatophages).

Figure 2. House dust mite. Source: Pixabay.com

Physical factors

Ventilation, interior temperature, degree of humidity, lighting, and noise are important physical factors to consider in diagnosing a sick building.

The mixtures of all the mentioned pollutants, in addition to the existence of adverse physical factors, can have additive, synergistic or antagonistic effects on human health.

Solutions

Among the possible recommendations to solve the sick building syndrome, we can mention the following:

-Execute architectural designs with optimization of ventilation and minimum air supply between 10 to 20 L / s. per person. In places where the above has not been done, mechanical ventilation is recommended to reinforce natural ventilation, as well as cleaning and maintenance of ventilation equipment, avoiding air recirculation.

-In health care centers and hospitals, the use of HEPA filters (High Efficiency Particulate Air filters) and laminar air flow are recommended.

- Comply with the WHO recommendations to maintain air quality, where concentration limit values ​​are established for 28 organic and inorganic chemical compounds.

-Use activated carbon filters, a highly absorptive material, which retains many VOC pollutants in its large active surface.

-Use carbon monoxide detectors, which are inexpensive and easily installed, and abide by environmental regulations of no smoking indoors.

-Use non-polluting construction materials and eliminate the use of asbestos, as well as avoid using furniture, insulating foams or upholstery that contain formaldehyde.

-Restrict the use of dangerous household cleaners. In some countries the use of sodium hypochlorite is only allowed in hospitals as a disinfectant.

-Clean indoor environments frequently to remove particles from surfaces and floors, together with the use of natural insecticides, such as extracts from some plants (basil, mint).

References

1. Guieysse, B., Hort, C., Platel, V., Muñoz, R. and Ondarts, M. (2008). Biological treatment of indoor air for VOC removal: Potential and challenges. Biotechnology Advances. 26: 398-410.
2. Huismana, M., Morales, E., van Hoofa, H. and Kortac, SM (2012). Healing environment: A review of the impact of physical environmental factors on users. Building and Environment. 58: 70-80. doI: 10.1016 / j.buildenv.2012.06.016
3. Masseya, D., Masiha, J., Kulshresthaa, A., Habila, M. and Tanejaab, A. (2009). Indoor / outdoor relationship of fine particles less than 2.5 μm (PM2.5) in residential homes locations in central Indian region. Building and Environment. 44 (10): 2037-2045. doi: 10.1016 / j.buildenv.2009.02.010
4. Stolwijk, JA (1991). Sick-building syndrome. Environmental Health Perspectives. 95: 99–100. doi: 10.1289 / ehp.919599
5. Wolkoff, P., Wilkins, CK, Clausen, PA and Nielsen, GD (2016). Organic compounds in office environments - sensory irritation, odor, measurements and the role of reactive chemistry. Indoor Air. 16: 7–19.