When the air quality problem occurred at NIEHS in 1981, far less was known about indoor air pollution than is known today, and there was a strong emphasis on energy conservation. As a result of the emphasis on energy conservation at that time, building engineers at facilities across the country had reduced the air exchange rate of air handling systems and initiated other conservation measures. NIEHS began moving employees into its new facility at Research Triangle Park, North Carolina, on April 11, 1981. The facility was constructed in five modules, each with its own air handling system. Modules A and B were administrative spaces; modules C, D, and E were laboratories. According to NIEHS officials, the laboratory modules required their air handling systems to make a 100-percent exchange of the air, whereas the administrative modules had varying amounts of fresh air added, depending on the outside temperature. Shortly after moving into the new facility, some employees in module A began complaining of respiratory problems and eye and throat irritation. Most of the complaints came from the second floor of module A, where most of the administrative employees had office space. One employee went to the hospital on April 20, 1981, complaining of respiratory problems, and a subsequent worker’s compensation claim attributed the illness to her work environment. According to the U.S. Consumer Product Safety Commission, formaldehyde is normally present at low levels, usually less than 0.03 ppm, in both outdoor and indoor air. Moreover, homes or offices furnished with products that release formaldehyde into the air can have levels of more than 0.03 ppm. The Occupational Safety and Health Administration’s (OSHA) occupational safety standard for formaldehyde in 1981 was 3.0 ppm; the current standard is 0.75 ppm. Indoor formaldehyde levels can vary greatly, depending on the type of building materials and furnishings used, the length of time that these materials have had to off-gas, the temperature and humidity, and the amount of fresh air brought into the building. Indoor formaldehyde levels can be reduced by using materials that contain less formaldehyde, airing the materials out before allowing employees into the space, and increasing the amount of fresh air brought into the building. Although formaldehyde levels can also vary with the temperature and humidity, these factors are controlled in an occupied building and, thus, may not have much effect. In response to requests from your office, two letter reports were issued, one by NIEHS and the other by the Deputy IG of the Department of Health and Human Services, addressing issues involving complaints by employees that they may have become ill after being exposed to the air in the new facility. NIEHS’ report, dated March 31, 1997, addresses the events and health effects that may have been caused by exposure to formaldehyde when the new facility was first occupied in April 1981. The IG’s letter report, dated August 15, 1997, addresses NIEHS’ (1) grievance procedures and treatment of employees, (2) compliance with appropriate policies and procedures regarding employee complaints, and (3) venting and other practices to ensure proper ventilation before the facility was occupied. NIEHS does not have data showing what the air quality was inside its new facility when employees began moving into it on April 11, 1981, or during the first 5.5 months that the building was occupied. NIEHS officials said that such monitoring for airborne contaminants was not common practice at the time. They also said that during these 5.5 months, the air handling system was adjusted to improve the air distribution in module A to help alleviate respiratory problems that some employees were experiencing because it was not immediately recognized that indoor air contaminants could be originating from within the space. In response to the concerns of some employees, NIEHS contracted with the School of Public Health at the University of North Carolina to monitor the air throughout modules A and B and to analyze the results to determine the quality of the air. The initial testing began in September 1981. At our request, an indoor air expert at the Environmental Protection Agency (EPA) extrapolated the range of possible formaldehyde levels in module A when the employees first moved into the space in April 1981. He concluded that those levels were probably higher than the levels measured in September of that year. The initial monitoring, which took place on September 28 and 29, 1981, found that the formaldehyde levels on the second floor of module A ranged from 0.1 to 0.34 ppm—well below OSHA’s standard in effect in 1981. Subsequent monitoring between January 20 and March 1, 1982, by the School of Public Health and others showed formaldehyde levels that were no higher than 0.044 ppm. The monitors were placed on top of desks, in closed wooden bookcases, and in other locations and attached to the clothing of some employees. Formaldehyde levels, however, may have been higher when the employees first moved into the space than when the measurements were taken because research shows that formaldehyde levels in enclosed spaces decrease rapidly during the first few days to several weeks. The contractor also sampled the air in modules A and B for 22 other organic substances and detected minute amounts—less than 0.1 ppm—for 10 of these substances, such as benzene, toluene, and trichloroethane. According to the contractor, the level for each of these substances was well below the standard in effect at the time. An air quality survey done by the National Institute for Occupational Safety and Health for NIEHS in March 1982 reported that the primary source of the formaldehyde was the particle board in the office furnishings. NIEHS officials said that adjustments were made to balance the air flow and introduce more outside air in module A during the first 5.5 months to alleviate respiratory problems that some employees reported. According to the officials, because the air was not being monitored during this period, the levels of formaldehyde that the employees were exposed to are unknown. The officials also said that in the early 1980s, air quality measurements were not usually made when employees first moved into buildings because indoor air quality was generally not recognized as the serious health concern that it is today. We asked the indoor air expert from EPA to use NIEHS’ air monitoring data to extrapolate a range of possible formaldehyde levels in module A when the employees first moved into the space in April 1981. The expert said that the limited amount of data available made it difficult to estimate the possible formaldehyde levels for the period before NIEHS began monitoring the air. However, with the available data as input for a formaldehyde decay curve, the expert’s mathematical extrapolation showed that the initial formaldehyde levels probably ranged between 1.2 and 7.5 ppm when the employees first moved into module A—higher than the levels measured in September 1981. In light of his knowledge about formaldehyde off-gassing from building materials and office furnishings, and the variables that can affect the rate of off-gassing, he said he believed that the actual levels were near the lower end of the range and were probably less than 2.0 ppm, which would be below the occupational safety standard that existed in 1981. Moreover, he stated that the formaldehyde levels probably declined quickly during the first few days to several weeks and continued to decline over time. NIEHS officials, however, do not believe that initial formaldehyde levels can be accurately modeled because of the multiple variables that could have affected the concentrations. They said that the lack of reliable information on such variables as the amount of formaldehyde in the materials when manufactured, the temperature and humidity conditions during the period, and the air exchange rates makes any extrapolation results highly suspect and speculative. Given such uncertainties, they believe that the initial formaldehyde levels were probably at the lower end of the extrapolated range because the furnishings had been installed some time before module A was occupied in April 1981. The General Services Administration’s (GSA) guidelines recommend that air handling systems in buildings be tested to determine if they are operating in accordance with specifications. Although the GSA guidelines in effect at the time called for test and balance certifications to be prepared before buildings were occupied, the Health and Human Services Regional Office Facilities Engineering Corps that was responsible for overseeing the building’s construction did not have the certification for module A signed until September 29, 1981, 5.5 months after employees moved into the module. NIEHS officials said that they adjusted the air handling system during the first 5.5 months in an effort to alleviate the employees’ discomfort. However, an April 27, 1982, memorandum from NIEHS’ Health and Safety Manager said that the air handling system could not have been in proper balance on September 29, 1981, as certified, because the agency continued to adjust the system to improve the air flow and the air exchange rate after the certification was signed. A time line summarizing the key events during the first several months of occupancy is in appendix I. The short-term effect of formaldehyde is irritation of the eyes and respiratory tract—in particular the nose and throat and, possibly, the lungs with concentrations as low as 0.41 ppm. Because formaldehyde changes quickly into other compounds when it contacts tissue, other body parts, by and large, are not adversely affected by inhaling formaldehyde. Surveys of the known research show there is no evidence that short-term exposure to formaldehyde affects the musculoskeletal, cardiovascular, immunological, neurological, reproductive, developmental, endocrine, renal, or hepatic systems of the human body, while only “a few . . . vague” gastrointestinal effects have been found. Moreover, the effects it has on the eyes and respiratory tract usually pass quickly once the exposure ends. Furthermore, predominant research results have found that people with asthma react no differently to formaldehyde exposure than do those without asthma. According to the National Institute for Occupational Safety and Health, short-term exposure to concentrations of 20 ppm of formaldehyde is immediately dangerous to the life and health of humans. Long-term exposure of laboratory animals to formaldehyde at a concentration of 2.0 ppm has not been shown to produce nasal cancer.