Molds, Mildew and Sick Building Syndrome

Sick Building Syndrome and its Indicators:
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 term "building related illness” (BRI) is used when symptoms of diagnosable illness are identified and can be attributed directly to airborne building contaminants.
Indicators of SBS include:
• Building occupants complain of symptoms associated with acute discomfort, e.g., headache; eye, nose, or throat irritations: 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.
• 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 health issues 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:
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 lAQ while minimizing energy consumption, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 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.

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 (VOC's) including formaldehyde. Environmental tobacco smoke contributes high levels of VOC's other toxic compounds, and respirable particulate matter. 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 exhaust, 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 irrigation 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.

Solutions to Sick Building Syndrome:
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.

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. Adsorbent beds may remove some specific gaseous pollutants, 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.

What do Environmental Inspectors look for?
• Basement water entry
• Condensation in crawl spaces or attics
• Roof leaks or ice damming
• Stucco and EIFS
• Plumbing leaks
• Reduced air flow in forced air HVAC systems
• Improperly vented furnaces, heaters,
water heaters, fireplaces
• Dirty duct work
• Stored cleaners, solvents, chemicals

Signs of possible Indoor Air Quality problems:
• Presence of molds and mildew
• Unusual and noticeable odors, stale or stuffy air
• Feeling noticeably healthier outside the building Noticeable lack of air movement
• Dirty or faulty central heating or air
conditioning equipment
• Damaged flue pipes or chimneys
• Excessive humidity
• Tightly constructed or remodeled building

Molds, Mildew, Fungi, Bacteria and Dust Mites:
Are some of the main biological pollutants inside the building/home. Some, such as pollen, are generated outside the home. Mold and mildew are generated in the home and release spores into the air. Mold, mildew, fungi and bacteria are often found in areas of the home that has high humidity levels, such as bathrooms, kitchens, laundry rooms or basements. Dust mites and animal dander are problematic when they become airborne during vacuuming, making beds or when textiles are disturbed.

Molds and dust mites thrive in areas of high
humidity. Mold grows on organic materials such as paper, textiles, grease, dirt and soap scum. Mold spores float throughout the house, forming new colonies where they land. Dust mites thrive on dead human skin cells and in textiles such as bedding, carpeting and upholstery. When these textiles are disturbed during vacuuming, making beds or walking on carpet, the dust particles become airborne. Pollen, plant material that enters through windows or on pets, and animal dander also become airborne when disturbed. Infectious diseases caused by bacteria and viruses are generally passed from person to person through physical contact, but some circulate through indoor ventilation systems.

Molds make up the largest component of the fungal classification, with over 60,000 separate species; the two terms often are interchanged indiscriminately. Regardless of which type of fungal matter, they all share the characteristics of being able to grow without the benefit of sunlight. This means that the only things necessary for fungus to proliferate, are a viable seed (known as a spore), a nutrient source, moisture and the right temperature. This explains why you often find fungal infestation in damp, dark and hidden spaces. Light and air circulation has a tendency to dry things out, make the area inhospitable for the fungus.

Another trait is that they can grow both through physical expansion as well as through the spread of spores, process scientists term "sporation". Once they get a foothold in a particular location rapid growth across the surface is possible if the moisture source is sufficient. If the moisture source starts to decrease many mold species will go into a sporation phase where they grow and release a large number of microscopic spores into the air.

Cleaning up and Controlling Mold Contamination:
The key to controlling fungal growth is to remove the moisture, the nutrients, or the source of spores. Physical removal is the best choice for plaster, drywall, ceiling tiles, cellulose insulation, cardboard boxes, and other such materials that harbor visible fungal contamination.

In less extreme cases, removing the moisture source and cleaning the surface with a sanitizer/biocidal agent can be effective. If such techniques are employed, it is essential that the sanitizing agent come in full contact with the fungal material for the required amount of time. Whether it is excess humidity, condensation or moisture intrusion, as a result of roof leaks, pipe failures, or subgrade seepage, to err in either one of these critical control activities is to invite recontamination. This is why the ACGH guidelines call for porous materials that have been wet for longer than 48 hours be removed, regardless of whether the leak came from a clean or dirty water source.

The cleanup and/or removal of fungal contamination require appropriate work practices and personal protective equipment. Anyone, who is going to intentionally disturb fungal contamination in any way, should protect themselves with a respirator or filtering face piece with a minimum of an N-99 rating on the face piece.

Surgical gloves underneath cotton or leather work gloves are critical for individuals who are involved in the removal of contaminated materials. If it is clean up and sanitation, heavy-duty rubber gloves are necessary to protect the worker from possible chemical exposures. Large-scale removal or cleanup projects may require the use of disposable body coverings, hoods and booties, to minimize the cross-contamination from work areas, to clean areas in the building.

Depending on the type and amount of material to be dealt with it may be necessary to isolate the work area from other areas in the building, through use of plastic sheeting, to seal doorways, windows, vents and other openings. If the potential for airborne dispersion of contamination is significant, it may be necessary to utilize large filtering fans to create negative pressure inside the specific work area. As such, many large mold remediation projects take on the appearance of an asbestos or lead abatement job site.

Hazardous Materials:
Asbestos, formaldehyde and other organic solvents, and leaded paint duct are the main ones. The hazardous materials can be released into the air when you remove paint, hang cabinets, or disturb other existing products that contain these materials. Paints, stripping and finishing products and adhesives can also create indoor air pollution.

Asbestos is any of six naturally occurring fibrous minerals found in certain rock formations. Of the six, chrysotile, amosite and crocidolite are most commonly found in building materials. When mined and processed, asbestos is typically separated into very thin fibers. Because asbestos is strong, incombustible and corrosion resistant, asbestos was used in many commercial products. Its use peaked in the period from World War II into the early 1970's. When inhaled, asbestos fibers can cause serious health problems.

Formaldehyde is a chemical that is released into the air as pungent gas. It is often used as a preservative or as an adhesive in pressed wood products, such as paneling and particleboard, and furniture. Formaldehyde causes eye, nose, and throat irritations; wheezing and coughing; fatigue; skin rashes; headaches; loss of coordination; nausea; damage to liver, kidneys, and the central nervous system; and severe allergic reactions. It has been linked to cancer.

Lead is a gray metallic solid. It is a heavy but soft metal that is extremely resistant to corrosion and relatively impenetrable to radiation. Lead was mined extensively for the mass production of lead solder for plumbing fixtures and became what seemed to be the perfect additive to paint in order to increase the durability of interior and especially exterior coatings. But, ironically the seemingly perfect additive has now been deemed extremely hazardous and according to many government agencies, is the number one health hazard for children and the most wide spread pollutant in the U.S.

Other Organic Solvents are those that evaporate into the air. Some may be flammable. Following are some of the compounds listed on product labels: petroleum distillates, mineral spirits, chlorinated solvents, carbon tetrachloride, methylene chloride, toluene, trichloroethane and formaldehyde.

Combustion Pollutants:
Are gases or particles that come from smoking and the burning of fuels - natural gas, propane, wood, oil, kerosene, and coal. The resulting harmful gases include carbon monoxide, nitrogen dioxide, sulfur dioxide, particulates and excess water vapor.

Combustion pollutants enter the home from a variety of sources. Any heating appliances that burn fuels - furnaces, boilers, water heaters, fireplaces, stoves, space heaters, ranges and clothes dryer- introduce combustion gases. These pollutants also are caused by tobacco smoking, automobile exhaust entering from a garage, and activities involving the use of internal combustion engines, welding or soldering.

Harmful build ups of these gases can occur when exhaust from combustion equipment is not properly vented to the outside of the home, combustion equipment is not in good working order and is not regularly inspected for safe operation, and a negative pressure balance exists between the inside and outside of the home.

Carbon Monoxide:
Is an odorless, colorless gas that can be fatal when breathed. It's sometimes difficult to determine if carbon monoxide is the culprit, because its symptoms are similar to flu and allergies. Low levels can cause nausea, dizziness, weakness and muscle ache. Higher doses can impair judgment, cause paralysis or coma, and death.

Radon:
Is a radioactive gas that has been found in homes all over the nation. It comes from the natural breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon typically moves up through the ground to the air above and into the home through cracks and holes in the foundation. Radon can enter through well water. Any home can have radon problems. This means new and old homes, well-sealed and drafty, and homes with or without basements. Testing is the only way to know if radon is present.
Health Effects:
In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities.

Health effects from indoor air pollutants may be experienced soon after exposure or, possibly years later. The likelihood of immediate reactions to indoor air pollutants depends on several factors. Age and preexisting medical conditions are two important influences. In other cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies tremendously from person to person. Pollutants commonly found in indoor air can be responsible for many harmful effects.

A number of well-identified illnesses, such as Legionnaire's disease, asthma, hypersensitivity, pneumonitis, and humidifier fever, have been directly traced to specific building problems. These are called building-related illnesses. Most of these diseases can be treated, nevertheless, some pose serious risks.

Health effects may show up years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease, and cancer, can be severely debilitating or fatal. It is prudent to try to improve the indoor air quality even if symptoms are not noticeable. While pollutants commonly found in indoor air are responsible for many harmful effects, there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems.

Most people are aware that outdoor air pollution can damage their health but may not know that indoor air pollution can also have significant effects. EPA studies of human exposure to air pollutants indicate that indoor air levels of many pollutants may be 2-5 times, and occasionally, more than 100 times higher than outdoor levels. These levels of indoor air pollutants are of particular concern because it is estimated that most people spend as much as 90% of their time indoors.

Over the past several decades, our exposure to indoor air pollutants is believed to have increased due to a variety of factors, including the construction of more tightly sealed buildings, reduced ventilation rates to save energy, the use of synthetic building materials and furnishings, and the use of chemically formulated personal care products, pesticides, and household cleaners.

In recent years, comparative risk studies performed by the EPA and its Science Advisory Board (SAB) has consistently ranked indoor air pollution among the top five environmental risks to public health.

While pollutant levels from individual sources may not pose a significant health risk by themselves, most homes have more than one source that contributes to indoor air pollution. There can be a serious risk from the cumulative effects of these sources. Fortunately, there are steps that most people can take both to reduce the risk from existing sources and to prevent new problems from occurring.

Published by the:
Environmental Assessment Association
Alexandria, MN 56308
www.iama.org/eaa.html