Issue Date: November 6, 2006
Out With The Bad, In With The Good
If you have headaches and get drowsy at work, you may think your symptoms are directly related to the type of work you do. But before you start sending out résumés, consider that the cause for those ills could be poor indoor air quality.
Understanding the root causes of bad air in buildings has spawned a cottage industry of air-quality specialists. One of the leaders of this field is organic chemist Jeffrey C. May, a building consultant and certified indoor air-quality professional who has investigated thousands of buildings and analyzed more than 20,000 air and dust samples.
May lectures nationally, and he has authored key books on the topic: "My House is Killing Me!" and "The Mold Survival Guide." In his latest offering, "My Office is Killing Me! The Sick Building Survival Guide," May moves from the home to the buildings where we learn, work, shop, and play.
"When occupants experience a cluster of certain symptoms indoors, and the symptoms do not point to a specific disease, the illness is sometimes referred to as sick-building syndrome (SBS)," May writes. "Symptoms due to SBS usually abate within hours or days (say, over a weekend) after sufferers leave the building and reappear when they enter the building."
With enthusiastic sleuthing, May applies his knowledge of airborne biological and chemical hazards and the physics of air and water flow in buildings to track down the origins of poor indoor air quality. He tells readers that air-quality problems in offices, hospitals, shopping malls, schools, and other public spaces stem from similar sources. Common problems include vapors and particulates from some cleaning compounds, solvents, and plastics; gases such as carbon monoxide and nitrogen dioxide; lead dust from paint; and pesticides. Other issues exacerbating these problems include contaminated heating, ventilation, and air-conditioning (HVAC) equipment; excessive or inadequate relative humidity; and inadequate ventilation.
Typical SBS symptoms—beyond headaches and fatigue—can include dry, itching, and irritated eyes or skin; stuffy or runny nose and sneezing; sore or dry throat and cough; and shortness of breath or wheezing. In addition to SBS, there are building-related illnesses (BRIs), which include occupational asthma, hypersensitivity pneumonitis, and humidifier fever, that are caused by bioaerosol or particulate matter arising from living things: bacteria, mold, plants (pollen), and animals (pet dander and dust mite droppings). For example, legionnaire's disease is a BRI caused by bacteria in air cooling towers, piping, and hot tubs.
May presents a series of case studies grounded in basic science to demonstrate how construction techniques, human activities, and physical laws governing the flow of energy and matter can spread contaminants in buildings. Water is not toxic or allergenic, for example, but if it infiltrates buildings through walls it can turn concrete into a growth medium for molds and bacteria. Squeamish readers may not appreciate the sometimes graphic descriptions of what constitutes food for these organisms: particles of skin, pet dander, residual chemicals, the aforementioned fecal material from dust mites, and more.
In a section titled "Diseased Decor," May describes common building materials and furnishings that can be a source of air contaminants. Among these are fungicides in paints that volatilize and react with ozone in the air to generate a foul sulfurous odor. Another example includes items made of vinyl plastics, such as window frames, communications cables, and even three-ring binders, which contain phthalate plasticizers that release odorous octanol and may have developmental impacts for children. Still another example is floor tile from which additives leach and react with the alkaline concrete beneath to form a strong odor.
When investigating poor indoor air quality, researchers like May often start by considering physical symptoms that may be experienced by just a few of a building's occupants. These symptoms may come and go or be ascribed to multiple causes. To complicate this ambiguity further, exposure to indoor air contaminants is rarely monitored on a routine basis and is usually only related to intermittent facility use, such as weekday working hours.
The book presents numerous such cases from May's personal experiences or from professional journals and describes how he or his colleagues determined the causes of the associated health effects by weaving together the threads of chemical and biological hazards with mysterious exposure routes. This may sound like the making of a not-so-exciting risk assessment, but that's not the case. Risk is a function of hazard and exposure. When hazard and exposure are well-characterized, risk can be predicted.
In one interesting case, a facility manager was at his wit's end with a restroom because a fishy odor was so strong that office workers refused to use it. May determined that a light fixture had cracked and the nylon plastic base melted from overheating. He describes how nylon is made with 1,6-hexanediamine and explains that the degraded nylon had formed diamine by-products. Some of the members of this class of compounds are cadaverine (1,5-pentanediamine) and putrescine (1,4-butanediamine), which as their names suggest "produce downright disgusting odors," May relates. Replacing the light fixture removed the source of the odor, and a good cleaning of the bathroom surfaces with dilute vinegar to neutralize the diamines eliminated the lingering smell to the delight of everyone involved.
Another case involved Boston's Brigham & Women's Hospital, where a number of staff members were affected by exposure to latex in gloves and glutaraldehyde used as a sterilizing agent. Some 300 of the hospital's 1,800 nurses reported symptoms related to contact with these materials, and 50 employees sued the building's HVAC contractors for poor ventilation associated with the exposure. The hospital committed nearly $8 million to clean the facility. Now, the hospital is a model for responsible management of indoor air quality, according to May.
Though some of May's explanations seem excessively simplistic, such as describing the behavior of molecules by analogy to marbles, I was grateful for clarity and simplicity on less familiar topics, such as boilers and furnaces and molds, mites, and mycotoxins. His colorful stories and plays on words are worth the read for people like me who appreciate good humor. There is one story about an orangutan who suffered health problems related to a ventilation system with fiberglass fibers in it; fortunately, it had a relatively happy ending.
One criticism of the book is that some of May's suggested solutions are shortsighted: His advice to swimmers affected by the air quality of an indoor pool is to swim outdoors, which is impractical in winter for an avid swimmer. Another issue for me is that May is myopically focused only on improving the indoor environment, suggesting in some cases that the best solution to a problem is to simply send the pollution outdoors rather than find a way to prevent it. A discussion of how products can and are being designed so they don't release irritating, sensitizing, or toxic chemicals would have been more productive.
For example, large health care organizations such as Kaiser Permanente are specifying for their facilities the use of materials as diverse as carpeting and intravenous bags that don't contain polyvinyl chloride or diethylhexyl phthalate. In the realm of cleaning products, a growing number of product formulators are submitting their products for review and recognition by ecolabels issued by consumer groups or by the Environmental Protection Agency's Design for the Environment Formulator Program. This program has created the CleanGredients online database, which my colleagues and I at the GreenBlue Institute have helped develop. CleanGredients is helping companies to design products that are optimized for human and environmental health.
Overall, "My Office is Killing Me!" is an interesting read and a good resource for information on indoor air quality. This book is important because it increases awareness of the causes of SBS and offers solutions rather than blame. It also raises awareness of technical issues regarding building materials and products commonly used to furnish or clean buildings that may contribute to indoor air-quality problems. It certainly should give chemists food for thought while daydreaming in our offices.
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