From the Lab to the Marketplace (1995)

Enhancing Indoor Air Quality

Research on the indoor environment can help reduce the cost of health problems related to poor indoor air quality. An improved indoor office environment can increase worker productivity as well. If such measures avert even one or two absentee days per person, the savings can equal the total cost of all building energy used by that employee for an entire year.

Estimated geometric mean radon concentration by county for Minnesota. Darker shades indicate higher indoor radon levels. Homes in unshaded counties have estimated concentrations below 2.5 pCi/L (picocuries per liter); darkest counties are greater than 5.5

Estimated geometric mean radon concentration by county for Minnesota. Darker shades indicate higher indoor radon levels. Homes in unshaded counties have estimated concentrations below 2.5 pCi/L (picocuries per liter); darkest counties are greater than 5.5 pCi/L.

People are indoors about 90% of the time, and indoor air pollutant concentrations often substantially exceed outdoor levels—creating a staggering healthcare cost of about $1 billion annually. Although exposure to air pollutants is dominated by indoor exposure, almost all research and regulatory attention is on outdoor air quality. Indoor air pollutants are responsible for premature deaths in 10,000 lung cancer patients annually (caused by radon), 1,500 deaths due to accidental carbon monoxide poisoning, and 10,000 related medical visits. Each year exposure of young children to environmental tobacco smoke causes an estimated 150,000 to 300,000 lower respiratory tract infections, such as bronchitis and pneumonia. Asthma—with its $6.2 billion annual U.S. healthcare cost—is exacerbated by poor indoor air quality. The indoor environment also affects the rates of transmission of important infectious diseases such as influenza, tuberculosis, and the common cold. More than 20 million cases of influenza occur annually in the U.S.

Unless properly conceived and implemented, some energy-saving measures can create indoor air quality problems. Mitigating these problems can waste energy—excess ventilation without heat recovery, for example. LBNL recognized that both energy efficiency and the quality of the indoor environment must be optimized, and in the 1970s, LBNL established the Indoor Environment Program. With one of the world's premier research groups on the environmental effects of indoor radon, this program has provided basic insights into how radon gas from the soil enters homes. (After cigarettes, radon is the second largest cause of lung cancer.) LBNL researchers use geographic information systems to pinpoint areas of the country with the highest radon levels. These results are helping to craft national policy recommendations for more effectively and efficiently identifying regions where houses with elevated concentrations can be found, and once found, to utilize energy-efficient remediation techniques.

The well-known but poorly understood "sick building syndrome," which may affect as much as 20% of all new office buildings, has also been studied at the Laboratory. Among the conclusions of our research: occupants in structures with air conditioning suffer a greater number of building-related health symptoms than occupants in structures with natural ventilation.

The productivity of the U.S. work force increasingly depends on fast and dependable electronic communication and equipment. Electronic equipment failures can impede work performance and engender costly repairs. There is substantial evidence that the deposition of aerosols on circuit boards (leading to electronic short circuits) and the action of corrosive gases on electronic circuits and electrical contacts is a major cause of such failures.

As an example of the economic significance of these failures, consider the telephone industry. The annual cost of circuit-board failures in the 300,000 telephone switching offices of the U.S. is approximately $1 billion, and about 20% ($200 million) of these failures can be traced to indoor air pollution. Many of these failures are attributed to indoor environmental factors, although typical indoor environmental conditions are maintained in the telephone switching offices. Possible methods for reducing failures include improved filtration, better temperature and humidity control, and automatic control of ventilation based on outdoor particle concentrations.

The full-size mannequin in these photographs simulates a worker in a spray booth facing the exhaust filters. In experiments designed by an LBNL researcher, smoke was released by a prototype airvest in front of the mannequin to simulate spraying paint booth.

The full-size mannequin in these photographs simulates a worker in a spray booth facing the exhaust filters. In experiments designed by an LBNL researcher, smoke was released by a prototype "Airvest" in front of the mannequin to simulate the spraying of paint in the booth.

In addition to illuminating the basic processes influencing indoor air quality, LBNL's program stimulates and accelerates technologies and strategies for measuring and controlling indoor air pollution in energy-efficient ways. These technologies include low-emission building materials and appliances, heat-recovery ventilation systems, blower-door technology (for testing air leakage in buildings), and energy-efficient radon control technologies. An innovative "airvest" system promises to significantly reduce spraybooth worker exposure to pollutants while cutting ventilation energy costs in half. Researchers have also developed passive samplers for indoor air quality (for example, the formaldehyde-based air samplers now sold by Air Quality Research in North Carolina).

Research at LBNL has made substantial contributions to twelve nationally used ASHRAE and ASTM standards pertaining to ventilation and air quality for the built environment. The program's leader has recently been appointed Chair of the U.S. Environmental Protection Agency's Science Advisory Board's Indoor Air Quality/Total Human Exposure Committee.