Akira Yamaguchi Professor of Environmental Health and Human Habitation
Throughout our lives we are exposed to environmental contaminants present in air, water, food and soil. The thrust of our research activities is the assessment of population exposures that occur in homes, offices, schools and during transit, as well as in the outdoor environment. Most of these assessment studies are carried out in conjunction with epidemiologic investigations.
In our recent NIEHS-sponsored exposure assessment study in two communities in southern California, individual ozone exposures were measured for approximately 200 children for 12 months. New personal monitoring techniques for ozone exposure were used in the study and methods are being developed for estimating individual lifetime exposures. With World Bank funded, we are conducting a series of environmental epidemiology studies in two industrialized regions in Russia. In addition to the assessment of existing environmental and health monitoring systems, several exposure and health surveys are being conducted to assess the impacts of air and water pollution in the Russian Federation.
Our studies, as well as others, reveal that people spend 65% of their time in their residences, 25% in some other indoor environment, 5-7% in transit, and usually less than 5% of their time is actually spent outdoors. The contaminant levels encountered in these indoor environments are important contributors to exposure, discomfort, irritation and health effects. Although we assess the effects of pollutants of outdoor origin (ozone, acidic particles, PCBs), we are particularly interested in pollutants of indoor origin (fungi, dust mites, nitrogen dioxide, tobacco smoke, lead, asbestos, volatile organic compounds, formaldehyde, radon, and others). Concentrations of these pollutants can reach levels many times greater than outdoor levels. NO2 levels in hockey rinks can exceed 1 ppm while homes with unvented gas cooking might vary between 20 and 100 ppb. In homes across North America, the presence of molds and mildew has been associated with substantial increases in upper and lower respiratory symptoms. Volatile components in gasoline can be 6 to 10 times higher inside a passenger car during rush hour traffic than values measured at standard urban monitoring sites.
We are also investigating ways to promote improved air quality through sustainable development strategies. Reducing the stresses on the earth’s environmental ecosystems (both human and non-human) will require better integration of environmental knowledge into all aspects of society (commerce, government, academic and religious). The concepts of pollution prevention, environmental cost accounting, risk-reducing based decision making and life-cycle analysis have to mature from academic concerns to functional activities within the public and private sectors of a market-driven economy. This premise motivates our current work to assess energy, comfort and indoor air quality for the design of healthier housing. The integration of environmental objectives into community development strategies needs reliable measures of sustainability. Projects assessing the total performance of conventional and manufactured housing in the U.S. and Japan are underway, along with others studying individual (family) and community decisions about home and community energy conservation measures. The impacts on indoor and regional air pollution of these measures, along with global scale carbon dioxide and other ecological indicators, will provide an improved accounting for cost-benefit analysis. Our objective is to construct the framework for linking zoning, purchases and practices, construction and appliance specifications, and pricing and tax strategies to energy and pollution consequences.
Ph.D., 1971, State University of New York at Albany
M.S., 1973, Harvard School of Public Health