Indoor air pollution is here, there, everywhere
By Michael Sims
FEBRUARY 1, 1999: Your home is your castle. It's where you feel safe from domineering bosses, deranged commuters, armed hoodlums, and even acid rain. We close the windows, set the thermostat on our artificial climate, and keep the world at bay.
As many monarchs have learned while hiding in their strongholds, however, sometimes the enemy lurks within the castle walls. Nothing proves this rule better than the little-known topic of indoor air quality. At various times of year in Nashville, there are daily updates on ozone levels, pollen counts, and other toxins and irritants that seem to lie in ambush outside our doors. But there are relatively few reminders about the environmental dangers that can await us at home indoors.
These risks include famous villains such as radon and asbestos and lesser-known enemies, including mold and chemical emissions from manufactured products. More and more studies trace certain asthma triggers and other respiratory problems to our indoor environments. In the mid-1980s, the EPA performed a pivotal study in which many buildings were determined to contain several times the level of pollutants found outside their walls--frequently the same pollutants, merely concentrated in the self-contained indoor environment. And the same problems that plague us at home can also lurk in the workplace.
There are a number of thorny problems associated with indoor air quality issues. One is the increased energy efficiency of buildings constructed since the energy crisis of the 1970s. Tightly built rooms, new heating and air-conditioning systems, even windows that don't open to the outside world, are presumed examples of progress which contribute to indoor air pollution. In various military studies, soldiers living in newer barracks reported respiratory and other environmental problems far in excess of their fellows housed in older buildings.
One scientist describes this phenomenon as the "Annette Funicello Effect." The term is tongue-in-cheek, but the point is serious. Just about the time that families moved indoors to vegetate on the sofa with the Mouseketeers and their successors, other changes were also taking place. We were surrounding ourselves with more and more manufactured objects, including furniture, rugs, cleaners, and other items that emit chemical pollutants. The combination meant that Americans--and many other people around the world--were spending their lives in ever more artifical environments.
Manufactured products are not the only problem, of course. One issue is simply hygiene, as proven by Legionnaires' disease. Even this famous ailment is an indoor air quality issue. It got its name in 1977, after it attacked veterans attending the American Legion Convention in Philadelphia the year before. Over 180 people contracted the pneumonia-like illness, and 29 of them died. When researchers at the Center for Disease Control in Atlanta looked into the matter, they traced the outbreak to a bacterium that had grown in poorly maintained intake vents in the hotel's heating and air-conditioning system.
"Why do we care about indoor air?" asks Janice Nolen, program director of the Tennessee chapter of the American Lung Association. "Part of it is because we spend 90 percent of our time indoors. We've become an indoor society. We're either in our homes, our offices, our schools, or our cars. And in many cases the air indoors is not as good as it should be."
Deadly DaughtersOne villain we hear a lot about nowadays is radon, a term which sounds as if it should be from science fiction. It is an odorless, tasteless, colorless gas produced by radioactive decay, the breakdown of the considerable amount of radium found naturally in the world around us--in rock strata, in the soil itself, and therefore in groundwater, too.
As radium decomposes toward a final, stable state, it produces a succession of particles called progeny or daughters. The radioactive offspring get into the air, where they attach to dust or other microscopic and near-microscopic particles. These extremely small particles wind up inhaled into our lungs, where they find their way into the deep recesses. Scientists think that even inside the lungs radon particles are still decaying, which is how they lead to lung cancer.
"Since the mid-'80s," says Nolen, "the EPA and the Lung Association and other national health associations have been trying to get the word out about radon." The Lung Association estimates that 14,000 lung cancer deaths annually can be attributed to radon. It is the second-leading cause of lung cancer in the United States, behind smoking. "If you live in a house that has elevated radon levels," warns Nolen, "your risk of getting lung cancer is geometrically higher than otherwise."
Testing--the only way to measure this silent, invisible threat--reveals that radon is found in homes throughout the United States, especially in the Northeast. Concentrations of it, and therefore levels of health hazard, vary enormously, depending upon such factors as the thickness of bedrock in a region. The result of these natural processes is compounded by the nature of human habitation, which traps radon and concentrates it, greatly increasing the danger.
"We're finding elevated levels in homes all over the country," Nolen says. "There's no way of telling whether your house has it or not, unless you test. New houses can have it; tight houses can have it; old houses can have it."
The natural variation in soil types and rock depths concentrates more radon in some regions than in others. Not surprisingly, such a geologically diverse state as Tennessee reveals plenty of variation. Both East Tennessee and southern Middle Tennessee have higher concentrations of radon than do some other areas. "However, this is not to imply that any area is without risk," Nolen adds. "There are elevated levels in houses in every county of the state."
Even in a particular region of the country, an individual's exposure to radon can vary, depending upon everything from weather to how much water is in the soil. It varies from day to day and even from morning to evening.
That's one of the reasons why the EPA encourages long-term testing, to calculate a more accurate picture of exposure levels. Radon is measured in units of picocuries per liter of air, and a measurement of 4 pCi/L is the level at which EPA recommends you fix the problem at home. The National Cancer Institute maintains that for every additional increase in exposure, your risk of lung cancer increases dramatically.
Until the mid-1980s, radon was regarded as strictly an occupational hazard, a threat solely to uranium miners. Its effects are documented in a long-running study of thousands of miners. Then a curious incident occurred during the construction of a nuclear power plant in Pennsylvania. There was as yet no radioactive material being produced at the site, but one man kept setting off the alarm when he walked through the newly erected radiation-detecting doorway.
Security personnel assumed that the alarm was a malfunction of the new doors, but an examination proved them wrong. The radioactivity was indeed coming from the man himself--from his shoes and clothes and body. Finally, the source of the radiation was traced back to his house, where he was found to be exposed on a daily basis to 16 times the maximum amount of radiation permissable at work.
If there is a positive side to radon, it is that, among the many disease risk factors besieging us in the modern world, it's one that can be prevented or remedied relatively easily. Janice Nolen sums up the solution: "Ventilation takes the radon from beneath the house and basically pipes it out, so that it's not going to be in the air that you breathe. Once it's outside, it's diluted enough that the risk is very low.
"This is the time of year when we encourage people to check their houses," adds Nolen. "In the wintertime, because of air pressure changes, and because houses are closed up, you will get the highest levels of radon in the home." The Nashville office of the Lung Association has available two kinds of kits: those that measure four to seven days and those that measure from three months to a year.
The Planning StageSteve Hays likes to say that his company wrote the book on indoor air quality. Hays Gobbell Partners, Inc. is an architectural, engineering, and environmental consulting firm. During its 21-year existence, it has been involved in the design and implementation of environmental projects across the U.S. The book Hays refers to is a 1995 text and sourcebook he co-wrote with partners Ronald Gobbell and Nicholas Ganick, Indoor Air Quality: Solutions and Strategies. Individually and together, the partners have written many papers on the topic, and lecture and consult across the country.
It isn't unusual for engineers and architects to be in partnership. What is unusual about this firm is that Steve Hays is a chemical engineer. The unexpected partnership has led to a thriving practice with two distinct components. First, there is traditional building design, which is primarily commercial, as in the work they did for the current Nashville airport construction and the new Tennessee Bureau of Investigation headquarters.
"The other major part of our practice," Hays explains, "is consulting in the environmental, health, and safety area. What this mix allows us to do is to view architecture with a strong environmental component and to view environmental issues with a strong architectural component. Take asbestos, for example. Most firms that consult on asbestos are asbestos specialists but don't necessarily know much about the architecture or the engineering components of the building."
Asbestos was the first environmental issue that Hays Gobbell dealt with, back in 1981. Nowadays, one of the major questions is radon. Hays points out that to design and construct a new building that will prevent radon migration into the space is fairly simple as long as it is planned from the beginning of the design process. The specifics depend upon whether the building has a basement or a crawl space or some other construction. This consideration of environmental issues from the moment the architect picks up a pencil is one of the late 20th century's true innovations in design.
"The problem we face as designers," Hays explains, "is that most owners are not interested in worrying about such things. It's a matter of us trying to educate people. Sometimes we're successful in getting them to consider it, and sometimes we're not."
Fortunately for health-minded consumers, this is a burgeoning field. "Many manufacturers are now offering products that have lower emissions of chemicals into the air than their previous products did," Hays points out. "Therefore it's pretty easy for us as architects to go to the literature and find a carpet, for example, that has been manufactured to be a low-emitting product. The issue for consumers is whether the designers they choose understand the impact that product selection has on the final outcome."
As usual, the obstacle is money. Many building owners are unwilling to spend the extra dollars so that designers can research and purchase alternative, environmentally friendly products. But, as is frequently the case, extra money spent thoughtfully in the planning stages can reduce later expenditures. Planning from the beginning to make the indoor environment a healthier, more comfortable, and more humane workplace results in greater job satisfaction, lower employee turnover, reduced health issues, and ultimately fewer lost days of work.
Many new commercial buildings simply start out with a poor environmental plan. The problem is the lack of what architects call proper building commissioning--a planned way to bring a building into service in such a manner that the indoor environment is protected rather than harmed by the process of inhabiting the building. Many indoor air quality problems in new buildings are caused by the attempt to occupy the space immediately after construction is finished, or even while construction is still in progress.
Hays explains the problems resulting from this hasty scenario: "Every owner wants to occupy a new building immediately. But most products--no, all products--that emit volatile organic compounds into the atmosphere do so during the first two or three weeks after they're installed. Afterward the emissions begin to decline at an exponential rate.
"Let's use paint as an example. Everybody has walked into a freshly painted room. Even if you're using low-emitting paint, it still smells like fresh paint. If you can complete a building, and then have it stay vacant for a week or two, and you ventilate it very well, then by the time people occupy it much of the emissions will be gone."
When buildings are properly commissioned, the inevitable product emissions dissipate instead of being absorbed by the unsuspecting new inhabitants or lingering in the environment to be absorbed by people later. "Consider the formaldehyde that may be emitted from some adhesive that's being used in the building," Hays says. "That compound can be emitted from a building product and absorbed by an office chair--to be emitted later at a slower rate. So being sensible about how you start the building up, and being willing to take the time to let products cure properly, can make all the difference in new buildings."
School DaysIn the field of indoor air quality, as in most environmental problems, each generation does what it can with the knowledge available. Then the next generation builds upon the preceding and goes forward from there. Nowhere else is this more apparent than in the quickly changing attitudes among public school officials.
"The science of indoor air quality is an evolving field," says Tom Hatfield, who heads the battle against indoor air problems in Metro Nashville schools. "We find new things every day."
He points out that aside from changing environments and new pollutants, there is also an increasing awareness of pollutants that were present all along but went unrecognized. A decade ago, seminars in the field pointed out that 2,300 types of pollutants are produced as byproducts of cigarette smoke. In contrast, at a recent seminar Hatfield found that scientists had increased the number of recognized pollutants to 4,000.
Hatfield has plenty to keep him busy. The Metro Nashville educational system comprises 128 public schools, occupying 160 buildings. They are used daily by more than 71,000 students and close to 9,000 employees. Air quality is a constant concern.
"In Nashville schools," Hatfield says, "we solve about 92 percent of our air quality problems. Another four percent seem to solve themselves. For that last four percent, we normally call outside environmental engineers in."
There are many issues to be sorted. "We deal a lot with molds and mildew. In the last 10 to 12 years, one of the things we've been seeing in schools--not only in schools, but all across America--is three times as many individuals diagnosed with allergies. And we've started a program where we're taking all the carpet out of foyers and hallways--the high-traffic areas in our schools--because so much stuff is tracked in. One of the things we run into with the newer buildings--and some older ones--is we get complaints about a bad smell and we find that a sanitary sewer and a grease trap are tied together. Now, a sewer is a horrible smell, but the odor that comes from a grease trap is much worse."
Naturally, radon is an ongoing issue.
"We've tested--at least randomly tested--classrooms in every building in the Metro school system," Hatfield says. "We're installing a passive radon system in every new building built. Basically what it does is suck the soil gas out from under the slab, injects it into the atmosphere above the roof line, and it dissipates quite rapidly there. We disallow it to get into the building."
When the EPA first started testing for radon, one Nashville classroom was found to have a radon level of 126 pCi/L, with the baseline alarm level being 4. Formerly the room had been a home economics classroom, and when it was converted into a regular classroom no one sealed the holes in the floor that led to a conduit. The radon level was reduced to 10 merely by sealing the holes.
"When we talk about air quality, what we're talking about is sensitivities," Hatfield insists. "There are individuals out there that are extremely sensitive. You and I may go into an environment and not notice anything at all, but then you may have a child or even a staff member who has a terrible allergic reaction. Most of them are associated with respiratory problems, but sometimes we do see rashes."
As with handicap access, responses to such sensitivities have to be built around the few individuals who experience the problem, not the many who don't. "For example, we've started mainstreaming our physically challenged children. We have children out there in wheelchairs who may already have a respiratory problem. So we just have to stay on top and make sure that the environment is clean."
While knee-deep in air quality problems, Hatfield is nonetheless optimistic about the future: "More and more people are aware of the problem. I think the people who are graduating from college now as teachers are being educated to be conscious of air quality issues. For example, if you've got a classroom full of children, and about twelve or one o'clock they begin laying their heads down on their desks, they're tired, they're dragging--that tells us we may want to check our carbon dioxide levels in there.
"Years ago, you'd get an air quality call, and it'd be one child in a school of 400 students was getting sick. There wasn't a lot of attention paid to that. The mindset was, you got 400 people there and only one got sick; it's baloney. Now we recognize that, yes, we could have one very sensitive child or staff member, or even a sensitive visitor to come in there and have a reaction."
Nowadays those single complainers are more likely to be seen as canaries in a coal mine--not quick to complain, but hypersensitive to their environment.
Understanding of environmental issues accumulates slowly. It takes time to even recognize a problem as such, to determine its origins, carefully measure its extent and variations, and extrapolate from all the information to predict short- and long-term effects. Naturally, this is as true of indoor air quality issues as it is of anything else. But the ultimate goal is certainly a worthy one--to try to make homes, offices, and schools ever more safe from some of the invisible enemies that prowl the world around us.
News & Opinion: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Cover . News . Film . Music . Arts . Books . Comics . Search
© 1995-99 DesertNet, LLC . Nashville Scene . Info Booth . Powered by Dispatch