A term coined by the World Health Organization identifying a condition which incorporates symptoms of a psychosomatic and physical nature that appear in connection with artificial room environments, which have a genuine sickness value, and lead to lasting suffering in the people concerned.
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Introduction of Sick Building Syndrome

The term “sick building syndrome” (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. The complaints may be localized in a particular room or zone, or may be widespread throughout the building. In contrast, the term “building related illness” (BRI) is used when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants.

A 1984 World Health Organization Committee report suggested that up to 30 percent of new and remodeled buildings worldwide may be the subject of excessive complaints related to indoor air quality (IAQ). Often this condition is temporary, but some buildings have long-term problems. Frequently, problems result when a building is operated or maintained in a manner that is inconsistent with its original design or prescribed operating procedures. Sometimes indoor air problems are a result of poor building design or occupant activities.

Indicators of SBS include:

• 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 BRI include:

• 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. 
It is important to note that complaints 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. 
Causes of Sick Building Syndrome 
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 SBS. In an effort to achieve acceptable IAQ 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 (see ASHRAE 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 (VOCs), including formaldehyde. Environmental tobacco smoke contributes high levels of VOCs, other toxic compounds, and respirable particulate matter. Research shows that some VOCs can cause chronic and acute health effects at high concentrations, and some are known carcinogens. Low to moderate levels of multiple VOCs 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.

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.

A Word About Radon and Asbestos…

SBS and BRI are associated with acute or immediate health problems; radon and asbestos cause long-term diseases which occur years after exposure, and are therefore not considered to be among the causes of sick buildings. This is not to say that the latter are not serious health risks; both should be included in any comprehensive evaluation of a building’s IAQ.

Building Investigation Procedures

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:

• the occupants "the HVAC system" possible pollutant pathways
• 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 walk through 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.

Solutions to Sick Building Syndrome

Solutions to sick building syndrome usually include combinations of the following:
Pollutant source removal or modification is an effective approach to resolving an IAQ 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 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, IAQ can be improved by operating the HVAC system to at least its design standard, and to ASHRAE Standard 62-1989 if possible. 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. (For a more detailed discussion of ventilation, read Indoor Air Facts No. 3R, Ventilation and Air Quality in Office Buildings.)

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 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 IAQ problems, they can work more effectively together to prevent problems from occurring, or to solve them if they do.

Unlike most other technologies on the market today, Oxyvital’s patented zeolite-based technology not only filters the air but purifies it to meet WHO optimal air quality standards, and does so without releasing toxic by-products.

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Presently Available Air Cleaning Methods: Do they work and are they free of side effects?

1. Ozone (sometimes called: activated oxygen, trivalent oxygen or nature’s air purifier)

At certain concentrations ozone is claimed to be able to kill microorganisms and remove certain odours. While many manufacturers still market ozone generators as air cleaners for residential use, world leading health organisations (e.g. EPA, Health Canada) warn against the use of ozone for air cleaning purposes since ozone generators can be harmful to human health even when they produce only low (allegedly “safe”) concentrations of ozone. It has also been proven beyond doubt by independent research that the use of ozone at safe levels is ineffective for air purification purposes. Here is a summary of the facts:

• Ozone is a well known lung irritant and can cause asthma attacks.
• Ozone does not remove particles. In order to kill microorganisms, the levels of ozone must be so high that they would also be harmful to human health. Conversely, at low levels which would be harmless to humans, ozone generators do not have any air cleaning benefit.
• If ozone is really as safe and reliable at killing microorganisms as manufacturers of ozone generators claim, why are they not recommended and used in critical hospital environments for the protection against airborne infectious microorganisms? By comparison, true HEPA filtration is recognised and recommended as the most effective means of airborne infection control (e.g. by WHO, CDC) and used in critical hospital areas worldwide. The CDC recommends HEPA filtration for the control of TB (which is one of the most infectious microorganisms known to mankind, killing thousands more people every day than the SARS virus has killed in total so far.)
• There is no independent evidence that the ozone generated by aircleaners actually kill sall the micro organisms in the air that flows through it, nor the microorganisms that may have been captured inside the air cleaner.

Here are some quotes that summarise the issue regarding ozone generators:

EPA (Environmental Protection Agency):

Conclusions:

Whether in its pure form or mixed with other chemicals, ozone can be harmful to health. When inhaled, ozone can damage the lungs. Relatively low amounts of ozone can cause chest pain, coughing, shortness of breath and, throat irritation. It may also worsen chronic respiratory diseases such as asthma as well as compromise the ability of the body to fight respiratory infections.

Some studies show that ozone concentrations produced by ozone generators can exceed health standards even when one follows manufacturer’s instructions. Many factors affect ozone concentrations including the amount of ozone produced by the machine(s), the size of the indoor space, the amount of material in the room with which ozone reacts, the outdoor ozone concentration, andtheamountofventilation.These factors make it difficult to control the ozone concentration inall circumstances.

Available scientific evidence shows that, at concentrations that do not exceed public health standards, ozone is generally ineffective in controlling indoor air pollution. The concentration of ozone would have to greatly exceed health standards to be effective in removing most indoor air contaminants. In the process of reacting with chemicals indoors, ozone can produce other chemicals that themselves can be irritating and corrosive.

Recommendation:

The public is advised to use proven methods of controlling indoor air pollution. These methods include eliminating or controlling pollutant sources, increasing outdoor air ventilation, and using proven methods of air cleaning.”
www.epa.gov/iaq/pubs/ozonegen.html

California Department of Health Services:

“Ozone-generating devices are being marketed to the public as a solution to indoor quality problems. Ozone generators are available in three forms: in-duct units for central air systems, portable indoor units, and personal units that are worn on the body. They are promoted as effective “air purifiers”, especially to people sensitive to indoor air pollutants. Manufacturers often refer to the ozone as activated oxygen, trivalent oxygen or nature’s air purifier to suggest that it is safe. They advertise ozone’s ability to oxidize indoor air pollutants and “leave only carbon dioxide, water, and breathable oxygen.” However, independent studies have shown that ozone generators do not effectively destroy microbes, remove odor sources, or reduce indoor pollutants enough to provide any health benefits. More alarming, these devices can generate excessive levels of ozone and may contribute to eye and nose irritation or other respiratory health problems for users.”

Are Ozone-Generating Air Cleaners Safe and Effective?

[...] However, it is not effective in air as a biocide (i.e. killer of bacteria and fungi), except at extremely high, unsafe levels. [...] A number of independent studies have concluded that safe levels of ozone do not effectively oxidize air pollutants or improve indoor air quality.

Recent Actions

[...] The Federal Trade Commission (FTC) filed suit against the industry’s leading manufacturer for violating their 1995 consent orderwithFTC.The1995orderrequiredthatozonegeneratormanufacturershalttheirpracticeofmakingunsupported,misleading health claims about the ability of their products to remove indoor air pollutants and prevent or relieve allergies, asthma and other conditions.”

For further information on this topic visit the following websites:

www.hc-sc.gc.ca/ehp/ehd/catalogue/psb_pubs/ozone_qa.htm
www.cal-iaq.org/o3_fact.html

IQ MB-AirClean Methods 5103 GB
INCEN AG Blumenfeldstr.15 • CH-9403Goldach • Switzerland
Tel.:+41718440844
Fax:+41718440845
e-mail:info@incen.com
www.iqair.com

2. Ionization

An ionizer is a device that disperses negatively (and/or positively) charged ions into the air. These ions attach to particles in the air, giving them a negative (or positive) charge so that the particles may attach to nearby surfaces such as walls or furniture, or attach to one another and settle out of the air.

Limitations of this method:

• The particles are not actually removed, but adhere to surfaces causing black walls and curtains. Since the largest surface in an inhabited room is offered by the human lung, this is also a likely surface where the charged particles can become lodged. Obviously this can cause severe short- and long-term health problems.
• As the particles loose their charge over time, this allows the particles to become airborne again.
• Ionizers do not filter gases or odours and many ionizers also produce harmful ozone as a by-product.

EPA (Environmental Protection Agency):

“In recent experiments, ionizers were found to be less effective in removing particles of dust, tobacco smoke, pollen or fungal spores than either high efficiency particle filters or electrostatic precipitators.” (Shaughnessy et al., 1994; Pierce, et al., 1996). www.epa.gov/iaq/pubs/ozonegen.html

3. Electrostatic/Electronic Air Cleaners (Precipitators)

(please refer to www.engr.psu.edu/ae/wjk/electro.html for a useful summary of this air cleaning method)

Shortcomings:

• Need to be serviced regularly.
• Maximumefficiencyca.95%,whichdecreasesfromtheveryfirstmomentofuse,sometimestobelow20%.
• Do not remove odours or gases.
• Noevidencethattheyeffectivelycontrolmicroorganisms.
• Not effective for larger airborne particles (e.g. allergens).

4. UV Light

Some air cleaners offer UV-light as an additional air cleaning stage. Although UV light has been shown to kill microorganisms at a certain wavelength and after a certain exposure time and light intensity, UV light is NOT a reliable way to sterilize the air. Also there is no scientific evidence that shows that UV light provides a benefit to a HEPA air cleaner.

• UV lamps create an increased health-risk, a disposal problem and added expense. The real reason why some manufacturers like to include UV lamps in their HEPA air purifiers is not their desire to increase the system’s efficiency, nor can they guarantee that the germs will actually be killed reliably by their UV lamps. The UV lamps are included because the manufacturer can make more money with replacement parts (for safety reasons, UV lights must be changed at least at yearly intervals).
• UV light does not remove odours or gases.
• Many health organisations warn health-care institutions not to use UV light for germicidal purposes due to their unreliability and because of the false sense of security which UV lamps create.

CDC (US Centres for Disease Control and Prevention):

“The use of UV lamps and HEPA filtration in one single unit would not be expected to have any infection control benefits not provided by the use of the HEPA filter alone.” www.cdc.gov/mmwr/preview/mmwrhtml/00035909.htm OSEH (Occupational Safety & Environmental Health Dept.) of Michigan University:

“The University of Michigan no longer supports the use of ultraviolet germicidal irradiation (UVGI) [...]

UVGI lends little to product sterility or personal safety in research settings, and has caused numerous hazardous exposures to employees while creating an expensive disposal problem.

Bulbs still in use will be removed and disposed as they fail over the next two years. Actually they effectively fail in 6 months, but appear to still be working (no visual indication of failure).” www.umich.edu/~oseh/UVbulb.pdf

5. Photocatalytic Oxidation (PCO)

This new technology for the filtration of gases is still in its infancy. No residential air cleaner manufacturer (irrespective of their claims) has yet managed to develop a system which uses this method effectively to remove gaseous contaminants as effectively as granular activated carbon (GAC). In order to work effectively, PCO air cleaners would become very expensive and would still not be as effective as GAC in removing gaseous pollutants. In a publication comparing the cost-effectiveness of activated carbon with PCO at removing Volatile Organic Compounds, the EPA writes:

“The analysis shows that, [...] the PCO unit would have an installed cost of 10 times greater, and an annual cost almost 7 times greater, than the GAC unit. It also suggests that PCO costs cannot be likely be reduced by a factor greater than 2 to 4, solely by improvements in the POC system configuration and reductions in unit component costs.” www.epa.gov/appcdwww/iemb/cost.htm

“Even with reductions by a factor of 2 to 4, POC would still be sufficiently expensive such that it would not likely be widely accepted for general indoor air applications.” www.epa.gov/appcdwww/iemb/insideiaq/ss98.pdf IQ MB-AirClean Methods 5103 GB

6. (True) HEPA filtration

High Efficiency Particulate Air (HEPA) filters, formerly called high-efficiency particulate arrestors, were originally developed during World War II to prevent discharge of radiactive particles from nuclear reactor facility exhausts. Due to their extraordinarily high filtration efficiency, HEPA filters have since become a vital technology in industrial, medical, and military clean rooms.

The filtering media of a HEPA filter is made of submicronic glass fibers in a thickness and texture very similar to blotter paper. A HEPA filter has been traditionally been defined as having a minimum particle removal efficiency of 99.97% for all particles of 0.3 micron and larger. In the words of the American Lung Association, to qualify as a “true” HEPA, the filter must allow no more than 3 particles out of 10’000 to penetrate the filtration media.

It is important to note that the mere use of a 99.97% efficient HEPA filter in an air cleaner does not automatically guarantee that the air cleaner’s actual efficiency is also 99.97%. In fact for most so-called HEPA air cleaners this is not the case. Badly pleated filters, leakage around the edges of the filter material or between the filter element and the housing often result in actual efficiencies between 50 – 95%. So instead of allowing only 3 particles out of 10’000 to come out of the air cleaner, these systems permit between 500 and 5’000 particles to be contained in the “cleaned” air stream.

The U.S. Centers for Disease Control and Prevention (CDC) therefore recommend: “Manufacturers of room-air cleaning equipment should provide documentation of the HEPA filter efficiency…”

CDC Recommendations and Reports, Vol. 43, No. RR-13, p. 81

Such documentation must come in the form of an independent test report, such as an efficiency classification in ac- cordance with an internationally accepted HEPA filter test norm (e.g. European Norm EN1822) which tests HEPA filters within the air cleaner housing, or a certificate that shows that the complete air cleaner has been tested and certified individually and has actually achieved the 99.97% efficiency for particles greater or equal to 0.3 micron.

7. Synthetic HEPA, non-true HEPA filtration

In an effort to cash in on the high-performance image of true HEPA filters, some air cleaner manufacturers have introduced so-called “HEPA-type” filters. Such filters are less expensive, but also hugely less efficient than true HEPA filters. On this point, the American Lung Association warns:

“[...] recently, filters made in the same physical style [as true HEPA filters] using less efficient filter paper are being referred to as HEPA filters or “HEPA-type” filters. Their actual efficiency may be 55% or less at 0.3 microns.”

http://www.lungusa.org/pub/cleaners/air_clean_chap3.html

The use of the word “HEPA” in conjunction with less efficient air cleaners is designed to mislead potential buyers into believing that the system can provide the same filtration efficiency as a true HEPA filter. Such practices are misleading (at best) and can be even harmful when it comes to health issues of allergy sufferers or if the system is to be used for airborne infection control.