Biological Methods

This document contains two reports by Drs. McCool and Samet and their colleagues who were funded to develop and test methods for measuring ventilation in freely mobile subjects at home or at work. Drs. Dennis McCool and Domyung Paek at the Memorial Hospital in Rhode Island measured ventilation with a body surface displacement (BSD) model. Each subject wore wide elastic bands containing coated wire coils around the chest and abdomen and had special magnets affixed to the breastbone and navel, which yielded data about their breathing patterns, breath frequency, and ventilation. In the second study, Dr. Jonathan Samet and colleagues at Johns Hopkins University wanted to develop methods for estimating ventilation from heart rate for future epidemiologic studies. They used the Heartwatch, a portable, commercial device combining a small transmitter worn on the subject's chest with a wristwatch-style receiver that records heart rate.

The human health effects that result from breathing air pollutants depend on the amount of pollutant inhaled from the air (exposure dose) and the amount of inhaled material that stays in the respiratory tract (retained dose). Because the retained dose of a pollutant may damage the respiratory tract and cause disease, it is a key factor for determining appropriate government regulations for air pollutants. Drs.

This report describes a study by Drs. Ultman and Ben-Jebria to develop a chemiluminescent ozone analyzer and constructed an ozone bolus generator with the goal of using bolus concentration-response methods to noninvasively measure the longitudinal distribution of ozone absorption in human lungs. The analyzer was based on the chemiluminescent reaction between 2-methyl-2-butene and ozone. Validation of the system was performed in excised pig and sheep tracheas, and the resulting absorption coefficient was computed.