GOVERNMENT officials and researchers across the country are investigating the possibility that the very measures meant to turn the nation's homes into energy fortresses in the name of saving fuel may be creating a whole new area for public concern; indoor air pollution.
The hazards have been neither totally defined nor, in many cases, thoroughly documented. And much of the data available has been collected under "worst possible conditions." But evidence is slowly accumulating that a number of common household features emit pollutants at potentially dangerous levels and that efforts to tighten houses to conserve energy, without providing sufficient ventilation, are making the problem worse.
"You spend so much time and money trying to build up a good product and you still end up with problems," lamented the vice president of a Washington-area home building firm recently.
A handful of new home owners in surburban Maryland have pressed for arbitration through such builder organizations as the Home Owners Warranty Corp. and the registered builders program. Behind the complaints are new houses that were built so tight -- so energy efficient -- they cut off air circulation. Humidity built up in the houses until condensation collected on the windows and drywall rotted.
"I'be experienced this in just about every county where I've built," said the developer, who recently lost his case in arbitration. "We've gone to R-30 insultation in the ceilings and R-11 in the walls and we're taping everywhere and caulking and sealing everything so right to limit air infiltration. In doing that, in houses without flues and where people don't use their exhaust fans, we're creating a lot of humidity."
And just as such "super tight" houses can collect moisture, they can also trap possibly damaging pollutants.
"There is a possibility that under certain conditions these (energy conserving) measures may cause an elevation of indoor pollution levels," said Demitrios Moschandreas, director of environmental sciences with Geomet, a Gaithersburg research laboratory working for the Environmental Protection Agency (EPA) and the National Academy of Sciences. "We are trying to determine the exact levels of pollutant concentrations in houses built specifically to conserve energy or in houses that have been retrofitted.
"No one knows the health problem," Moschandreas said. But "anything that is generated indoors may become a potential problem."
Government officials say current research may lead to standards for indoor pollution and changes in building standards and codes to require alternate, and still developing, ventilation techniques.
The pollutants include fumes from combustion of natural gas; radon released by naturally radioactive building materials; aldehydes, such as formaldehyde, leaked into the household air by furniture, carpeting, particle board, plywood and insultation; and common household sprays.
All are suspected of causing ill health effects, from minor eye irritation and nausea to chronic lung disease and cancer. Some, authorities fear, may be causing allergies and exacerbating symptoms among those already afflicted by chronic ailments.
Last December, Craig D. Hollowell, researcher at the Lawrence Berkley Laboratories, under contract to the Department of Energy (DOE) to investigate possible health hazards in homes and public buildings, told a conference in California that "one finds commonly today that gas stoves are installed in buildings and are not vented. The ovens typically are not connected to a ventilation system of the building. The top burners may be vented through the use of an exhaust hood, but these hoods are rarely used. We find that levels of carbon monoxide and nitric oxide and nitrogen dioxide very often exceed the EPA limits for exposure that one observes in the outdoor environment under very bad air pollution conditions."
Hollowell cited a study performed in England in which school children from homes using gas appliances showed a higher rate of respiratory disease than children from homes using electric appliances.
The Consumer Product Safety Commission (CPSC) recently issued a warning to consumers about health problems that might result from use of urea-formaldehyde foam insulation. The commission, which has received more than 300 consumer complaints regarding the foam, found that "continued exposure to formaldehyde gas can cause nausea and vomiting, respiratory difficulties, headaches, eye irritation and allergies." It said that "symptoms may develop anywhere from a few days to more than six months after the gas is released."
Urea-formaldehyde foam represents about 5 percent of the total home insulation market ahd has been used in about 500,000 houses already. An estimated 150,000 houses are fitted with the foam each year.
A team at Lawrence Berkley laboratories is also investigating formaldehyde as it is released in gaseous form by particle board and plywood. Formaldehyde is a common component in binding materials and is also leached by carpeting, curtains and furniture.
Another pollutant is radon. Many natural substances, such as rock and soil, and some building materials contain radium. When radium decays, it gives off radon, a radioactive gas. Radon is thought to be virtually harmless when it is released into the atmosphere at "safe background levels." Trapped in a house that is poorly ventilated, however, radon becomes a potential hazard. Some believe it can cause lung cancer.
"The problem that may occur," Hollowell told the conference, sponsored by the California Department of Consumer Affairs last December, "is that as one reduces ventilation in a space the radon gas buildup may be appreciable. There may be a potential health risk with time as people spend essentially 80 percent or more of their time in closed spaces."
Authorities working in the field say their chore is complicated by a lack of knowledge about what is a hazard and what is only a potential danger. For the most part, they do not know what levels of indoor pollution should be considered "normal." Problems with energy-tight houses have surfaced only within the last year or two in this country.
"There's been a lot of attention paid to outdoor air quality and very little paid to indoor air quality," said James Berk, project manager for indoor air quality studies at Lawrence Berkley. "So we don't know what the average levels are. There is a real lack of information in this area."
"There is no cause for alarm," said Moschandreas. But the potential risks, he conceded, "warrant further research."
"We've tested tight houses where there's no problem," said Howard Ross, program manager of architectural and engineering systems at DOE. "But there's clearly enough potential that we're putting a lot of money into it to find out more."
The money DOE is putting into it is about $10 million over a five-year period, Ross said, to fund research at Lawrence Berkley Laboratory. For the past two years, teams from Lawrence Berkley have been roaming the country in specially equipped vans to monitor pollution levels and ventilation in private homes, schools and hospitals.
"We have found cases where we feel some action should be taken," said Berk. "Even here in California. There are definitely situations where you have pollutants generated inside the house and you need to either seal up the sources, remove the sources or improve ventilation."
Monitoring has revealed, for instance, that in some houses the "air change," or rate of ventilation, was as low as one-tenth per hour (one "air change" is measured by the time it takes a quantity of outside air equal to the indoor volume to enter the house). A normal air change, Berk said, is about three-quarters per hour.
Several research organizations are studying standards issued in Europe, Denmark, Sweden and also Japan have experienced indoor pollution problems and have developed ventilation techniques to combat them. Gary Roseme of Lawrence Berkley is investigating devices with heat exchangers that would improve ventilation by increasing the flow of outside air into the house without sacrificing energy conservation.
"There are several design features that can be incorporated into a house and that can reduce these (pollutant) levels significantly," Roseme said.
Roseme says that methods being studied, including the ventilators and addition of vapor barriers, would cost a typical home buyer about $700.
"The approach we're taking," said Ross, "is to still build houses air-tight but to improve mechanical ventilation. We expect this to become a budding industry in this country."