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Allergy Air Filter - Sick building syndrome

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Sick building syndrome

Allergies - caused by bad air in a "Sick building"?

Employees of offices, schools, and day-care centres all around the world experience very similar indoor air problems currently known as "Sick Building" syndrome (SBS). People develop indoor air-related symptoms (fatigue, headache, muscle ache, memory and concentration difficulties, skin symptoms, flu symptoms, asphyxia, sensations of insufficient breathing air, and indigestion) without any apparent cause. Some 40 % of those with symptoms are unable to determine when the symptoms started, but they can isolate them to a specific building. "One sign of indoor air problems can be the onset of various irritation symptoms, often in the respiratory channels. When people reside in some other building, the symptoms ease or vanish. These are signs that the indoor air of a building causes these symptoms or in the least makes them more severe," says Doctor of Technology Risto Ruotsalainen.

Even such widespread problems can be alleviated if people are given the opportunity to have a say about their building's ventilation and temperature. Research also clearly shows that sick building symptoms increase if the ventilation system is insufficiently maintained or cleaned. Thus the ventilation system itself becomes the source of symptoms, a distributor of bacteria. According to researches air-filtering techniques would also be worth improving, as they could diminish symptoms and improve work productivity.

The concept of a "sick building" became known in Finland and elsewhere in the world in the 1980s, although its roots lie deep in the energy crisis of the 1970s. During that crisis the rapid rise in the price of oil resulted in hasty modifications to construction, heating, and ventilation techniques. Everything happened too quickly, and attention was paid only to energy saving. The old Finnish saying about throwing the baby out with the bath water came true: while energy was saved, major problems arose.

Indoor air was analysed only in relation to energy saving and heating up until the early 1980s. The perspective has changed since then and now includes the possible ways of avoiding mistakes and negative health effects.

The third stage is actually happening right now, as the owners of buildings are joining into discussions about indoor air quality (IAQ). Their participation came when indoor air researchers started to talk about the value and profitability of the buildings.

Fatigue and headache
The sick building syndrome began to appear on a wider scope some two decades ago in schools, hotels, day-care centres, and offices. People experienced more symptoms in big buildings with fully mechanical ventilation. Usually people mentioned symptoms resembling the flu, fatigue, headache and discomfort. It is true that such symptoms may occasionally occur also in healthy people, so a building can not be classified as sick before the users begin to have a plethora of symptoms.

Finland's harsher and colder climate sets somewhat different requirements for construction than the milder climates of southern countries do. Properly insulated buildings with no air leaks have to be constructed for energy saving reasons. This kind of construction emphasises the need to have controlled ventilation in every room although this kind of climate control does not always succeed.

It does not always succeed in the United States, either where only 20 % of office buildings are healthy, 40 % are usually healthy, 20 % suffer from problems with unknown causes, 10 % from problems with known causes, and 10 % of the buildings are sick. "Here in Hong Kong about one third of the buildings are classified as sick, which means that they have bad indoor air, among others problems. Similarly the indoor air of big malls where people often spend their free days should be significantly improved," claims Professor Frank Lee of Hong Kong Technical University.

Symptom occurrence
The table below describes the occurrence of work-related symptoms during the past three months in order of commonness, divided according to sex.

Work-related symptom Every week
All % Women % Men %
Nose irritation/blocked nose/runny nose 20 23 13
Eye itching/irritation 17 20 9
Fatigue 16 19 9
Hand skin dryness 15 19 6
Hoarseness or dry throat 14 16 9
Reddened/dry facial skin 11 13 5
Head feeling heavy 9 11 4
Headache 7 8 3
Scaling scalp or earlobes 6 7 4
Cough 5 6 4
Concentration problems 3 4 3
Nausea/dizziness 1 2 1
Source: Kari Reijula, Uusimaa regional institute of occupational health 2002

Finland copes better
Office employees and school staff experience sick building syndrome symptoms more than other workers. The reason for the symptoms has been studied extensively, and the targets of analysis have included, among others, organic compounds evaporating from building materials, microbes, humidity and temperature conditions of the air, air flux, noise, lighting, radiation, and, naturally, ventilation systems. Psychological factors at offices and other workplaces may also contribute to the occurrence of symptoms.

Finnish office employees appear to be slightly more satisfied with the quality of indoor air than their colleagues elsewhere in Europe. The share of the dissatisfied in Finland is "only" some 20 %, whereas an average of 30 % of European office employees is dissatisfied with the indoor air. This may also be a consequence of the fact that the issue may have received more attention in Finland and the Finnish research in the field represents the top of the world. Nevertheless we seem to have more asthma-type symptoms and common cold symptoms than elsewhere in Europe. This may be partly due to the dry winter air.

Factors affecting sick building syndrome

Chemical factors

  • volatile organic compounds (VOCs)
  • tobacco smoke
  • odours
  • floating dust
  • Physical factors

  • too high or low room temperature
  • too low air flow
  • too dry or humid air
  • too dim lighting
  • Biological factors

  • bacteria
  • fungus growths
  • Mental factors

  • too severe psychological burden
  • workplace bullying
  • inexperienced personnel management
  • Finnish researchers have shown that sick building symptoms increase visibly when the room temperatures of offices or schools are raised from 20 to 24 degrees centigrade. In other international researches the conclusions have been that sick building symptoms increase as temperatures rise.

    "Hong Kong has precisely the situation described above, as the temperature of outdoor air is way above 20 degrees centigrade for most of the year. Therefore symptoms increase significantly in poorly ventilated offices or schools," Professor Frank Lee points out.

    It has been shown indisputably that people experience less sick building symptoms if they are able to influence the air quality at their workplace, for example, by adjusting ventilation or temperatures. According to researches air-filtering techniques would also be worth improving, as they could diminish symptoms and improve work productivity.

    Symptoms caused by the sick building

  • Eye irritation
  • Irritation of nose, throat, and pharynx
  • Blocked nose, dry nose, and running mucus
  • Hoarse voice
  • Coughing
  • Dryness, reddening, and itching of skin
  • Allergic reactions of mucous membranes and skin
  • Headache
  • Nausea and dizziness
  • Fatigue
  • Allergy Air Filter
  • Olfactory sensations
  • New building syndrome
    But what could possibly be the reason for the fact that people who work in quite new office buildings often have sick building symptoms? After all, those buildings can not have mould damage yet.

    "I have been quite disturbed by this 'new building syndrome'. I can state with confidence that many office buildings have problems during their first six months," says Dr. Kari Reijula.

    Usually the exhausts concentrate in new office buildings during the night so strongly that the work hours of the employees are ruined until noon. This could be avoided, or at least the symptoms could be diminished, by running the ventilation equipment of the new building night and day for the first six months.

    The new building syndrome manifested itself in research for example at Finland's Broadcasting Company's Iso Paja building immediately after it opened. According to Dr. Kari Reijula new buildings often have such problems through the first year. "The ventilation system should not under any circumstances be shut down for the night. Otherwise the work of the whole office is disturbed by odours and stuffy air the following day."

    In a new office building the symptoms may also get worse because of the new office furniture. New furniture may emit very strong chemicals during the first months. Furniture no longer stays in a warehouse for months on end. Instead it is transported directly from the factory to the offices while the substances used for glues, varnishes, and paints etc. are still fresh.

    Complaints about indoor air conditions
    The table describes the relative shares of interviewees who have experienced problems every week (Uusimaa regional institute of occupational health, a study of over 12 000 employees in capitol area offices in 2002)

    Environmental problem Every week
    All % Women % Men %
    Dry air 35 42 19
    Stuffy air 34 39 21
    Dust or dirt 25 29 18
    Draught 22 25 14
    Noise 17 19 13
    Too high temperature 17 19 13
    Unpleasant odour 17 19 11
    Varying room temperature 16 18 11
    Weak lighting/dazzle 14 16 10
    Too low temperature 13 16 7
    Electric surfaces 8 9 4
    Smoking colleagues 4 4 3
    Source: Kari Reijula, Uusimaa regional institute of occupational health 2002

    Hallmarks of a healthy day-care centre

    • Correct temperature: During heating season the temperature should be 20-22 degrees centigrade. Deviations will have a negative effect on comfort and health.
    • Sufficient ventilation: Necessary ventilation requires 6 litres per second per person or 3 litres per second per one square metre of floor. At the same time the adjustment of the currents, cleanness of the filters, functioning of the heating units, cleanness of ducts and direction of incoming air should be checked.
    • No draught in winter: Ventilation and low temperatures cause the most draught. Other factors include surface temperatures and air leaks in structures.
    • No disturbing noise: The premises should be planned so that no disturbing noise can penetrate from outside sources and the building should house no noisy technical equipment.
    • No strong odours: It is always important to clear the origin of odours. Their sources may be construction and furnishing materials, people, or domestic pets. Various activities such as crafts also create impurities.
    • Correct cleaning methods: Cleaning should not raise dust in the air. Excessive use of water and cleaning chemicals may also cause problems. Cleaning should not be carried out during working hours.
    • Moisture damages are repaired: Moisture damages are often followed by mould fungus growth and negative health effects. If deficiencies are noticed in the moisture-related technical functioning of the structures or in heating and air conditioning equipment, repairs must be made.
    • The condition of the building is inspected: By inspecting the condition of the building and its indoor air, damages can be prevented.
    Source: Finnish Society for Indoor Air Quality

    Quality classes of indoor climate

    Individual indoor climate (S1)

    • The indoor air is excellent and temperatures are comfortable in winter and in summer
    • The user of the space can individually control the temperature conditions and improve the quality of the indoor air when needed by increasing the ventilation
    • The air quality and temperature conditions meet the special needs of the users (e.g. people with allergies, people with respiratory organ diseases, and the elderly)
    Good indoor climate (S2)
  • The indoor air quality is good and there is no draught
  • In hot summer days the temperature rises to uncomfortable levels
  • Satisfactory indoor climate (S3)

  • The indoor air quality and temperature conditions meet the minimum regulations
  • The air may feel stuffy at times and there may be some draught
  • Overheating is common in hot summer days

  • Source: Finnish Society for Indoor Air Quality





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