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sick building syndrome

Sick building syndrome

Sick building syndrome is a collection of symptoms that a building’s occupants can experience but without any obvious or specific illness or cause 1. The complaints may be localized in a particular room or zone, or may be widespread throughout the building. This feeling of ill health increases sickness absenteeism and causes a decrease in productivity of the workers. In contrast, the term “building related illness” is used when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants.

Signs and symptoms of the sick building syndrome are as follows 1:

  • Headache, dizziness, nausea, eye, nose or throat irritation, dry cough, dry or itching skin, difficulty in concentration, fatigue, sensitivity to odors, hoarseness of voice, allergies, cold, flu-like symptoms, increased incidence of asthma attacks and personality changes.

The cause of these symptoms is not known. It reduces work efficiency and increases absenteeism. Most of the complainants report relief soon after leaving the building, although lingering effects of neurotoxins can occur.

It is important to note these symptoms may result from other causes. These may include an illness contracted outside the building, acute sensitivity (e.g., allergies), job related stress or dissatisfaction, and other psychosocial factors. Nevertheless, studies show that symptoms may be caused or exacerbated by indoor air quality problems.

Sick building syndrome is believed to date back to the energy crisis of the 1970s. In response to the escalating costs of heating and cooling outside air as opposed to recirculated air, office buildings turned away from natural ventilation such as opening windows and air conditioning systems were introduced. However living and working in an environmentally controlled environment also means that pollutants are trapped in the air.

Indicators of sick building syndrome include 2:

  • Building occupants complain of symptoms associated with acute discomfort, e.g., headache; eye, nose, or throat irritation; dry cough; dry or itchy skin; dizziness and nausea; difficulty in concentrating; fatigue; and sensitivity to odors.
  • The cause of the symptoms is not known.
  • Most of the complainants report relief soon after leaving the building.

Indicators of building related illness include 2:

  • Building occupants complain of symptoms such as cough; chest tightness; fever, chills; and muscle aches.
  • The symptoms can be clinically defined and have clearly identifiable causes.
  • Complainants may require prolonged recovery times after leaving the building.

Sick building syndrome – house

Sick building syndrome can also occur due to factors of the home. Laminated flooring can cause more exposure to chemicals and more resulting sick building syndrome symptoms compared to stone, tile, and cement flooring 3. Recent redecorating and new furnishings within the last year were also found to be associated with increased symptoms, along with dampness and related factors, having pets, and the presence of cockroaches 3. The presence of mosquitoes was also a factor related to more symptoms, though it is unclear whether it was due to the presence of mosquitoes or the use of repellents 3.

Sick building syndrome causes

The following have been cited causes of or contributing factors to sick building syndrome:

  • Inadequate ventilation: In the early and mid 1900’s, building ventilation standards called for approximately 15 cubic feet per minute (cfm) of outside air for each building occupant, primarily to dilute and remove body odors. As a result of the 1973 oil embargo, however, national energy conservation measures called for a reduction in the amount of outdoor air provided for ventilation to 5 cfm per occupant. In many cases these reduced outdoor air ventilation rates were found to be inadequate to maintain the health and comfort of building occupants. Inadequate ventilation, which may also occur if heating, ventilating, and air conditioning (HVAC) systems do not effectively distribute air to people in the building, is thought to be an important factor in sick building syndrome. In an effort to achieve acceptable indoor air quality while minimizing energy consumption, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recently revised its ventilation standard to provide a minimum of 15 cfm of outdoor air per person (20 cfm/person in office spaces). Up to 60 cfm/person may be required in some spaces (such as smoking lounges) depending on the activities that normally occur in that space (https://www.ashrae.org/technical-resources/standards-and-guidelines/standards-interpretations/interpretations-for-standard-62-1989).
  • Chemical contaminants from indoor sources: Most indoor air pollution comes from sources inside the building. For example, adhesives, carpeting, upholstery, manufactured wood products, copy machines, pesticides, and cleaning agents may emit volatile organic compounds, including formaldehyde. Environmental tobacco smoke contributes high levels of volatile organic compounds, other toxic compounds, and respirable particulate matter. Research shows that some volatile organic compounds can cause chronic and acute health effects at high concentrations, and some are known carcinogens. Low to moderate levels of multiple volatile organic compounds may also produce acute reactions. Combustion products such as carbon monoxide, nitrogen dioxide, as well as respirable particles, can come from unvented kerosene and gas space heaters, woodstoves, fireplaces and gas stoves.
  • Chemical contaminants from outdoor sources: The outdoor air that enters a building can be a source of indoor air pollution. For example, pollutants from motor vehicle exhausts; plumbing vents, and building exhausts (e.g., bathrooms and kitchens) can enter the building through poorly located air intake vents, windows, and other openings. In addition, combustion products can enter a building from a nearby garage.
  • Biological contaminants: Bacteria, molds, pollen, and viruses are types of biological contaminants. These contaminants may breed in stagnant water that has accumulated in ducts, humidifiers and drain pans, or where water has collected on ceiling tiles, carpeting, or insulation. Sometimes insects or bird droppings can be a source of biological contaminants. Physical symptoms related to biological contamination include cough, chest tightness, fever, chills, muscle aches, and allergic responses such as mucous membrane irritation and upper respiratory congestion. One indoor bacterium, Legionella, has caused both Legionnaire’s Disease and Pontiac Fever.
  • Psychological factors: Excessive work stress or dissatisfaction, poor interpersonal relationships and poor communication are often seen to be associated with sick building syndrome.
  • Poor and inappropriate lighting with absence of sunlight, bad acoustics, poor ergonomics and humidity may also contribute to sick building syndrome. The symptoms of sick building syndrome are commonly seen in people with clerical jobs than in people with managerial jobs because professionals or managers have better working conditions. The symptoms are more common in females than in males probably because more females are in secretarial jobs, they are more aware of their health or a lesser dose of pollutants is required to manifest the effects. The symptoms are more common in air-conditioned buildings than in naturally ventilated buildings and are more common in a public sector building than in a private sector building 4.

These elements may act in combination, and may supplement other complaints such as inadequate temperature, humidity, or lighting. Even after a building investigation, however, the specific causes of the complaints may remain unknown.

Contributing factors

Even though they may not cause sick building syndrome, poor management practices and other causes of low morale can affect the way in which symptoms are perceived along with the level of discomfort which people will tolerate without complaint.

The reported incidence of sick building syndrome can therefore be affected by any factor that impacts on workers’ job satisfaction and morale, such as:

  • work interest level
  • work demands, such as work overload and/or underload
  • level of control over their work and environment
  • management response to complaints
  • lighting, noise and vibration levels
  • ergonomic factors
  • decor and other aesthetic factors.

Sick building syndrome prevention

Increase the ventilation rates and air distribution. The heating, ventilation and air-conditioning systems should be designed to meet ventilation standards in the local building codes. The HVAC system should be operated and maintained properly to ensure that the desired ventilation rates are attained. If there are strong pollutants, the air may need to be directly vented to the outside. This method is especially recommended to remove pollutants that accumulate in specific areas such as rest rooms, copy rooms and printing facilities. The ASHRAE recommends a minimum of 8.4 air exchanges per 24 hours.

Removal or modification of the pollutant source can be carried out by a routine maintenance of HVAC systems, replacing water-stained ceiling tiles and carpets, using stone, ceramic or hardwood flooring, proper water proofing, avoiding synthetic or treated upholstery fabrics, minimizing the use of electronic items and unplugging idle devices, venting contaminants to the outside, storing paints, solvents, pesticides and adhesives in close containers in well-ventilated areas and using these pollutant sources in periods of low or no occupancy. Allowing time for building material in new areas to off-gas pollutants before occupancy and smoking restrictions are some measures that can be used.

Air cleaning can be a useful addition to control air pollution. Air cleaning can be performed by ensuring uncongested interiors with open office designs, use of frosted glass and skylights that give access to natural light, terrace gardens, community spaces and indoor plants that absorb carbon monoxide and formaldehyde from the air. Air filters are also effective in removing some if not all of the pollutants.

Education and communication are important parts of any air quality management programme so as to work more effectively and efficiently to prevent and solve the health problems.

Legislation

Banning of smoking in the workplace or restricting smoking to designated well-ventilated areas away from the work stations and creating no-smoking zones with the help of laws. In some European countries, workers have a statutory right to be involved with the employer’s plans for changes in the work place.

Research

The principles of Building biology are as follows 5:

  • Site status: The building site should be geologically undisturbed. Residential areas should be away from industrial centers and main traffic routes and housing should have sufficient green space and should be in harmony with the surrounding environment.
  • Construction concepts: Natural, unadulterated and nontoxic building material should be used, walls, floors and ceilings should not be susceptible to mold or fungi, the basement should be waterproof and well -ventilated, the earth’s natural magnetic field should not be altered or distorted, production, installation and disposal of building materials should not lead to environmental pollution, building activities should not lead to exploitation of nonrenewable, rate resources.
  • Interiors: Lighting and color must mix well with the surroundings and not jar the senses, man-made electromagnetic radiation must be reduced as much as possible, interiors should be done by using natural materials without toxic content and should be economically designed, there should be no toxic outgases or harsh smells, indoor humidity should be naturally regulated, air pollutants should be filtered and neutralized, thermal insulation should be balanced with heat retention, use of solar heating should be encouraged, moisture content in new buildings should be low, protective measures against noise pollution and harmful infrasonic and ultrasound radiation must be ensured, natural balance of atmospheric electricity and ion concentration should be maintained (Table 1).

Table 1. Comfort levels recommended by the Chartered Institution of Building Services Engineers (CIBSE 1986)

ParameterRecommended level
Temperature (dry bulb)19-23°C
Relative humidity (RH)40-70%
More than 55% RH is needed in carpeted buildings with under floor heating to avoid electrostatic shocks
Ventilation
Delivery of fresh air8 l/s/person (minimum)
16 l/s/person where some smoking
25 l/s/person where heavy smoking
Total air supply4–6 air changes/hour
Air speed0.1–0.3 m/s. Less than 0.1 m/s causes stuffiness. More than 0.3 m/s causes draughts. For air speeds higher than 0.1 m/s, CIBSE recommends an increase in air temperature to take account of air movement
Sound46 dBA is the upper limit for general office work
Lighting500 lux for general office work, 750 lux for deep-plan offices and work at drawing boards, proofreading, etc.
[]Source 6 ]

Sick building syndrome symptoms

The complaints of discomfort and ill health that constitute sick building syndrome include the following:

  • Eye symptoms: dryness and irritation of the mucous membranes of the eye, often experienced as grittiness, stinging and watering of the eyes.
  • Respiratory tract symptoms: dryness and irritation of the throat, irritation of the nasal mucous membranes, often described as a runny, blocked or stuffy nose, sinus pain.
  • Other general symptoms that have been described include:
    • headaches,
    • lethargy or tiredness,
    • poor concentration.
    • nausea
    • dizziness
    • tightness in the chest
    • a sensation of difficulty with breathing
    • a sensation of ‘stuffiness’, odors and unusual tastes
    • exacerbation of other conditions, such as asthma.

Sick building syndrome diagnosis

Investigation of symptoms thought to be related to the internal environment of buildings requires consideration of a broad range of possible connective factors. It’s important to determine whether there are reasonable grounds to suspect that a problem exists and to also define the level of the problem.

To do so, the frequency and characteristics of the symptoms should be assessed. This is generally expected to give some indication of whether the cause is likely to be a specific and identifiable airborne contaminant or a general deficiency of dilution ventilation.

The assessment of the internal building environment can then be guided towards the more likely cause. A useful step is to take measurements of carbon dioxide concentrations in the workplace air to assess the suitability of the fresh air supply in relation to the human occupancy level.

Additionally, estimates of specific atmospheric contaminants can be undertaken if the inspection suggests the possibility of their presence in extreme concentrations.

If deficiencies are suspected as a result of the inspection findings, a further detailed assessment of air conditioning and ventilation design along with maintenance, cleanliness and function, may be recommended.

Sick building syndrome testing

This assessment can be done by an occupational hygienist.

The occupational health and safety resource center at Canada’s University of Western Ontario has devised a routine five-point survey for occupational hygienists to follow when investigating air quality complaints. Features include:

  1. a walk-through inspection to look for sources of contamination, such as photocopiers, insulation and cleaning materials,
  2. measurement of temperature, humidity, air movement and other comfort parameters,
  3. measurement of carbon dioxide to assess the ventilation efficiency,
  4. measurement of formaldehyde, carbon monoxide, ozone and respirable particles and
  5. examination of the ventilation system for causes of poor distribution, including tests for biological organisms in any water in the system[9]

The goal of a building investigation is to identify and solve indoor air quality complaints in a way that prevents them from recurring and which avoids the creation of other problems. To achieve this goal, it is necessary for the investigator(s) to discover whether a complaint is actually related to indoor air quality, identify the cause of the complaint, and determine the most appropriate corrective actions.

An indoor air quality investigation procedure is best characterized as a cycle of information gathering, hypothesis formation, and hypothesis testing. It generally begins with a walkthrough
inspection of the problem area to provide information about the four basic factors that influence indoor air quality:

  1. the occupants
  2. the HVAC system
  3. possible pollutant pathways
  4. possible contaminant sources.

Preparation for a walkthrough should include documenting easily obtainable information about the history of the building and of the complaints; identifying known HVAC zones and complaint areas; notifying occupants of the upcoming investigation; and, identifying key individuals needed for information and access. The walkthrough itself entails visual inspection of critical building areas and consultation with occupants and staff.

The initial walkthrough should allow the investigator to develop some possible explanations for the complaint. At this point, the investigator may have sufficient information to formulate a hypothesis, test the hypothesis, and see if the problem is solved. If it is, steps should be taken to ensure that it does not recur. However, if insufficient information is obtained from the walkthrough to construct a hypothesis, or if initial tests fail to reveal the problem, the investigator should move on to collect additional information to allow formulation of additional hypotheses. The process of formulating hypotheses, testing them, and evaluating them continues until the problem is solved.

Although air sampling for contaminants might seem to be the logical response to occupant complaints, it seldom provides information about possible causes. While certain basic measurements, e.g., temperature, relative humidity, CO2, and air movement, can provide a useful “snapshot” of current building conditions, sampling for specific pollutant concentrations is often not required to solve the problem and can even be misleading. Contaminant concentration levels rarely exceed existing standards and guidelines even when occupants continue to report health complaints. Air sampling should not be undertaken until considerable information on the factors listed above has been collected, and any sampling strategy should be based on a comprehensive understanding of how the building operates and the nature of the complaints.

Sick building syndrome treatment

Solutions to sick building syndrome usually include combinations of the following:

Pollutant source removal or modification

Pollutant source removal or modification is an effective approach to resolving an indoor air quality problem when sources are known and control is feasible. Examples include routine maintenance of HVAC systems, e.g., periodic cleaning or replacement of filters; replacement of water-stained ceiling tile and carpeting; institution of smoking restrictions; venting contaminant source emissions to the outdoors; storage and use of paints, adhesives, solvents, and pesticides in well ventilated areas, and use of these pollutant sources during periods of non-occupancy; and allowing time for building materials in new or remodeled areas to off-gas pollutants before occupancy. Several of these options may be exercised at one time.

Increasing ventilation rates and air distribution

Increasing ventilation rates and air distribution often can be a cost effective means of reducing indoor pollutant levels. HVAC systems should be designed, at a minimum, to meet ventilation standards in local building codes; however, many systems are not operated or maintained to ensure that these design ventilation rates are provided. In many buildings, indoor air quality can be improved by operating the HVAC system to at least its design standard, and to ASHRAE Standard 62-1989 if possible (https://www.ashrae.org/technical-resources/standards-and-guidelines/standards-interpretations/interpretations-for-standard-62-1989). When there are strong pollutant sources, local exhaust ventilation may be appropriate to exhaust contaminated air directly from the building. Local exhaust ventilation is particularly recommended to remove pollutants that accumulate in specific areas such as rest rooms, copy rooms, and printing facilities.

Air cleaning

Air cleaning can be a useful adjunct to source control and ventilation but has certain limitations. Particle control devices such as the typical furnace filter are inexpensive but do not effectively capture small particles; high performance air filters capture the smaller, respirable particles but are relatively expensive to install and operate. Mechanical filters do not remove gaseous pollutants. Some specific gaseous pollutants may be removed by adsorbent beds, but these devices can be expensive and require frequent replacement of the adsorbent material. In sum, air cleaners can be useful, but have limited application.

Education and communication

Education and communication are important elements in both remedial and preventive indoor air quality management programs. When building occupants, management, and maintenance personnel fully communicate and understand the causes and consequences of indoor air quality problems, they can work more effectively together to prevent problems from occurring, or to solve them if they do.

References
  1. Joshi SM. The sick building syndrome. Indian J Occup Environ Med. 2008;12(2):61–64. doi:10.4103/0019-5278.43262 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2796751
  2. Sick Building Syndrome. Indoor Air Facts No. 4 (revised) February 1991. https://www.epa.gov/sites/production/files/2014-08/documents/sick_building_factsheet.pdf
  3. Wang, J., Li, B., Yang, Q. et al. Sick building syndrome among parents of preschool children in relation to home environment in Chongqing, China. Chin. Sci. Bull. (2013) 58: 4267. https://doi.org/10.1007/s11434-013-5814-2
  4. Finnegan MJ, Pickering CA, Burge PS. The sick building syndrome: Prevalence studies. Br Med J. 1984;289:1573–5.
  5. ‘Room in the skies’ Outlook – life wellness. 2004. Feb, pp. 26–8
  6. Chartered Institution of Building Services Engineers. https://www.cibse.org
Health Jade Team

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