Sick building syndrome

Sick building syndrome (SBS) is a combination of ailments (a syndrome) associated with an individual's place of work (office building) or residence. A 1984 World Health Organization report into the syndrome suggested up to 30% of new and remodeled buildings worldwide may be linked to symptoms of SBS. Most of the sick building syndrome is related to poor indoor air quality.[1]

Sick building causes are frequently pinned down to flaws in the heating, ventilation, and air conditioning (HVAC) systems. Other causes have been attributed to contaminants produced by outgassing of some types of building materials, volatile organic compounds (VOC), molds (see mold health issues), improper exhaust ventilation of ozone (byproduct of some office machinery), light industrial chemicals used within, or fresh-air intake location / lack of adequate air filtration (see Minimum Efficiency Reporting Value).

Symptoms are often dealt with after-the-fact by boosting the overall turn-over rate of fresh air exchange with the outside air, but the new green building design goal should be to avoid most of the SBS problem sources in the first place, minimize the ongoing use of VOC cleaning compounds, and eliminate conditions that encourage allergenic, potentially-deadly mold growth.[2]

Symptoms

Building occupants complain of symptoms such as sensory irritation of the eyes, nose, throat; neurotoxic or general health problems; skin irritation; nonspecific hypersensitivity reactions; and odor and taste sensations.

It is possible for a dozen sick occupants to report a surprising array of individual symptoms, which may be dismissed as unconnected. The key to discovery is the increased incidence of illnesses in general with onset or exacerbation within a fairly close time frame - usually within a period of weeks. In most cases, SBS symptoms will be relieved soon after the occupants leave the particular room or zone.[4] However, there can be lingering effects of various neurotoxins, which may not clear up when the occupant leaves the building. In particularly sensitive individuals, the potential for long-term health effects should not be overlooked.

Causes

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The contributing factors often relate to the design of the built environment, and may include combinations of some or all of the following:

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In hot, humid climates, moisture is the primary culprit.

Exterior and demising interstitial wall cavities very often receive continuing loads of moisture due to unintentional, high humidity airflows through a building's matrix. Often such moisture is trapped and hidden within these cavities where it builds to 70% and 95% moisture saturation by weight. There are few if any, mechanisms that operate to dry out such wall cavities.

If such airflows are of hot, humid air, this moist, warm air may reach a dewpoint surface, especially if indoor temperatures are maintained much below about 78 degrees F. At this degree of moisture saturation, in this dark, undisturbed wall cavity space, most all molds, including stachy, thrive. Molds and bacteria rarely coexist. Molds produce generally toxic substances that create unwelcome, unhealthy environments for bacteria and insects, as well as human beings. The toxic substances generated by mold growth may become aerosolized, released and distributed to a much greater range by these unintentional airflows through the building's matrix until they may be inducted into the air conditioning and heating distribution systems and ultimately discharged into the breathing zone. These unintentional airflows create the toxicity and obscure the true source of toxicity and earthy odors as they distribute it.

Mechanical ventilation in a hot, humid climate may deliver water vapor into a building at the rate of approximately one pound of water per day for each cubic foot per minute per day of unconditioned outdoor ventilation air delivered.

Radon mitigation by mechanical ventilation in hot humid climates, (Florida) is known to create gradual increases in moisture saturation that suddenly lead to mold problems when moisture saturation of a favored mold food material reaches 70% by weight. This increasing moisture saturation process may take a few months or as long as four or more years.

The uninformed or poorly informed assume that the air conditioner will successfully remove such moisture, and it may if it is operating efficiently. Many air conditioners do not, and almost all of them decline in their ability to dehumidify efficiently over time. Residual moisture remains and soaks into materials as if they were sponges, on a march toward full saturation. In hot, humid climates, the worst months for mold are October, November, December and early spring...when air conditioners rarely operate and moisture saturation increases most rapidly.

Identification and termination of these unintentional building matrix airflows has rarely been recognized and acted upon, hence heroic efforts to heal the sick building have been largely unsuccessful. Out of a sense of frustration with enormously expensive and ineffective healing approaches, total building destruction is sometimes selected as a way out.

With proper application of currently available instrumentation, identification of unintentional building matrix airflows is relatively easy, quick and inexpensive for a knowledgeable, experienced, building science practitioner. Pressure and micropressure management can result in immediate odor and toxics dis

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tribution system termination. With application of correct technology, and often without installation of any additional equipment, relying only on what is already there, within hours of completion a sick building can begin a gradual drying out process to heal itself completely.

As Joe Lstiburek has said, the approach of building disassembly and rebuild or destruction on one hand (expensive) or micropressure management on the other (much less expensive) is decided by who is paying. Micropressure management correctly applied has the potential to eliminate the true cause of the sick building.

The other approach rarely addresses the cause and treats the symptoms only.

Indoor air quality (including smoking where not prohibited)

Toxic mold

Artificial fragrance, such as dryer sheets

Poor or inappropriate lighting (including absence of or only limited access to natural sunlight)

Poor heating or ventilation

Microbial or mite contamination of HVAC systems.

Bad acoustics or infrasound

Poorly designed furnishings, furniture and equipment (e.g. computer monitors, photocopiers, etc.).

Poor ergonomics.

Chemical contamination.

Biological contamination.

To the owner or operator of a "sick building", the symptoms may include high levels of employee sickness or absenteeism, lower productivity, low job satisfaction and high employee turnover. Clarification of the link between a sick building and employee health has and will likely continue to result in increased worker's compensation and personal injury claims. Business owners will likely find increasingly happy customers and a better bottom line with successful healing of sick buildings.

Prevention

Roof shingle cleaning non pressure removal of algae, mold & Gloeocapsa magma.

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Pollutant source removal or modification to storage of sources.

Replacement of water-stained ceiling tiles and carpeting.

Institution of smoking restrictions.

Use paints, adhesives, solvents, and pesticides in well-ventilated areas, and use of these pollutant sources during periods of non-occupancy.

Increase the number of air exchanges, The American Society of Heating, Refrigeration & Air Conditioning Engineers recommend a minimum of 8.4 air exchanges per 24 hour period.

Proper and frequent maintenance of HVAC systems

UV-C light in the HVAC plenum

Gender Differences

There might be a gender difference in reporting rates of sick building syndrome because women tend to report more symptoms than men. Along with this, there have been studies where they found that women have a more responsive immune system and are more prone to mucosal dryness and facial erythema. Also, women are alleged by some to be more exposed to indoor environmental factors because they have a tendency to have more clerical work where they are exposed to unique office equipment and materials (example: Blueprint machines), whereas men have jobs based outside of offices.[6]

Indoor Air Facts . Sick Building Syndrome

Introduction

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

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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

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. 

See www.epa.gov/radon  and  www.epa.gov/asbestos

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

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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.  For more information, see VOCs; Carbon Monoxide; Formaldehyde; Nitrogen Dioxide; Respirable Particles.

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.  For more information, see Biologicals and Mold.

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.

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

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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:

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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 Fact Sheet: Ventilation and Air Quality in Offices)

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.

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Aerotoxic syndrome

Aerotoxic syndrome

Is the name for the alleged long-term ill-health effects, which are alleged by some to have been caused by the breathing of pressurized cabin air in an airliner. The term was introduced on 20th October 1999 by Harry Hoffman, Chris Winder and Christophe Balouet.[1]

With the exception of the new Boeing 787, the air in a jet or turboprop aircraft cabin is typically supplied by bleed air from the aircraft’s engines. GCAQE, a political advocacy group for pilot and flight attendant labor unions, has alleged that some aircrew and passengers claim they have been made ill by toxins in engine oil that can enter the air supply.

As of 2009 this syndrome is not officially recognized.

Contaminated bleed air

Jet engines require a complex synthetic oil formulation for lubrication.The oil contains some anti-wear ingredients which could possibly be toxic to humans, in large quantities, such as tricresyl phosphate (TCP), an organophosphate. Engine bearing seals are installed for the purpose of ensuring that critical engine bearings are continuously lubricated, and also to prevent engine oil from leaking into the compressed air stream.

If a bearing seal fails and begins to leak, depending on the location of the seal, some amount of engine oil may be released into the compressed air stream. Oil leaks may be detected by odour, or in more serious cases, by smoke in the cabin. This is known as a “fume event”. Although most jet aircraft cabins have filters for the recirculated cabin air, the bleed air supply is not filtered.

In a flight safety bulletin to all operators, dated January 05, 2001, BAE Systems included the following information:

During the last year there have been several reports of the appearance of smoke or fumes originating from the air conditioning system. Investigation has identified most of the root causes of these incidents:

Technical (the majority), rectification of which prevented further occurrences.

Self-inflicted, such as ingestion of de-icing fluid, through the APU intake and into the cabin air supply.

Perceived, due to condensation in the air supply. This may occur if an inappropriate cabin temperature is selected, causing the air conditioning system to over cool the cabin air.

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There are many technical reasons why aircraft have smells or minor appearances of smoke from air conditioning systems including, for example, inappropriate temperature settings relative to ambient conditions or inadvertent ingestion of hydraulic fluid or de-icing fluids. Recently the main focus of attention has been on the possibility of oil from either the main power plant or the APU contaminating the cabin air via these systems. The air supply is protected from contamination by seals, which achieve maximum efficiency during steady state operation. However, they may be less efficient during transients (engine acceleration or deceleration) or whilst the engine is still achieving an optimum operating temperature. Improvements in seal design continue to improve efficiency, and when available, modifications are provided for the engines and APU.

Alleged health effects: incidents/possible sources

It has been alleged by two airline labor unions, that flight crews have been impaired or incapacitated on a number of occasions, following alleged exposure to fumes during flight. On 5 November 2000, both the pilot and co-pilot of a Jersey European Airways BAe 146 allegedly became unwell while landing at Birmingham International Airport, with both allegedly becoming nauseous, with the pilot allegedly experiencing double vision and having difficulty judging height. Despite this, he managed to land the aircraft safely. "The first officer and commander were taken to hospital and examined, but no abnormalities were found." The subsequent incident investigation report concluded that "There is circumstantial evidence to suggest that the flight crew on G–JEAK were affected by contamination of the air supply, as a result of oil leakage from the APU generator cooling fan seal into the APU air stream, and into the ECS system ducting. This contamination allowed fumes to develop, a proportion of which entered the cabin and cockpit air supply."

That same AAIB Report also noted that both the captain and the first officer had visited the forward toilet, before the onset of their symptoms. About the same time of the G-JEAK incident, another operator reported overuse of a disinfectant (formaldehyde) for the toilets and to clean the galley floor and then inhalation of the fumes from that chemical, would produce the identical symptoms reported by both the captain and first officer of G-JEAK. "The CAA notified UK Operators at that time (CAA ref. 10A/380/15, dated 2 August 1996) of this potential hazard, as the misuse of this agent was apparently widespread.

A COT service information leaflet, provided a list of possible sources of poor quality cabin air. Some of the items on that list:

Underfloor hydraulic leaks.

Ingestion of De-icing fluid into APU inlet.

Periodic maintenance task that is required to clean the forward galley oven.

Inappropriate or excessive use of CO2 (dry ice) by caterers.

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Toilet fluid spillage, leakage and also unapproved mixing of different disinfectant fluids within the toilet.

Leakage of the ran repellent system, or rain repellent contamination within the cabin or flightdeck.

Spillage within baggage bays.

Items stowed in overhead baggage bins.

The alleged ill-health effects that have been reported include cognitive problems, dizziness, disorientation, nausea, breathing difficulties, anxiety, mood swings, malaise, diarrhoea and various other neurological problems, particularly related to the autonomic nervous system.[12] Chronic fatigue syndrome (CFS) and Multiple chemical sensitivity (MCS) are also commonly reported by sufferers.[13] Government research states that adverse health effects of short duration do occur, but although it cannot rule it out, says that the available evidence is unable to conclude a link to long-term symptoms.[14]

Research

Ongoing research commissioned by the UK government's Department for Transport (DfT) has not managed to conclude a link to long term health. The campaigning groups GCAQE and the Aerotoxic Association (both are political advocacy groups) contest that these agencies are covering up the issue and trying “not to find a problem”.

According to a report by Prof Michael Bagshaw, there have been no peer-reviewed recorded cases of neurological harm in humans following TCP exposure. He points to an unpublished report from the Medical Toxicology Unit at Guy's Hospital in 2001 which looked at all exposures dating back to 1943 which showed that all documented exposures are to high concentrations greatly in excess of the amount present in jet oil. He also noted that studies in Canada and the USA were unable to detect TCP in the cabin during flight. Prof Bagshaw notes that the symptoms are "largely the same as those reported by participants in all phase I drug trials", and are similar to the symptoms experienced by patients suffering from chronic fatigue syndrome, gulf war syndrome, Lyme disease, chronic stress and chronic hyperventilation.

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