Research Reports

This report describes a study by Dr. Moon and colleagues to investigate the carcinogenic potential of 1-nitropyrene, a mutagenic constituent of diesel exhaust particles, using a hamster respiratory-carcinogenesis model. Male hamsters were exposed to 1 or 2 mg of 1-nitropyrene via intratracheal administration either once or twice a week for 92 weeks. In order to study activity as a cocarcinogen, 1 or 2 mg of 1-nitropyrene was administered in combination with 0.25 mg of the known environmental carcinogen benzo[α]pyrene once per week for 92 weeks.

This report from the HEI Multicenter CO Study examined the effect of carbon monoxide (CO) exposure of male human participants with coronary artery disease, with a particular focus on myocardial ischemia onset during exercise. The participants were exposed to air or to CO concentrations sufficient to elevate blood carboxyhemoglobin (COHb) levels to 2% or 4% during exercise. The primary health endpoints examined were the time to onset of exercise-induced angina, and the time to a predefined ST-segment change.

This report describes two pilot investigations for a longitudinal study of infants designed to determine if NO₂ exposure from cooking stoves increases the incidence or severity of respiratory infections during the first 18 months of life. In the first study, Drs. Samet and Spengler selected 147 households with electric or gas stoves and infants for home indoor monitoring of NO₂ concentrations; the infants\' mothers completed a daily calendar-diary on respiratory symptoms and provided illness information every 2 weeks.

This report describes a study by Dr. McGrath to investigate the effect of chronic exposure of rats to CO at high altitude. Male rats were exposed for 6 weeks to CO ranging from 0 to 500 ppm at simulated altitudes ranging from 3,300 to 18,000 feet. The following weekly measurements were taken throughout the exposure period: weight, hematocrit, hemoglobin, and carboxyhemoglobin concentrations. Arterial pH, partial pressure of CO in the blood (PCO₂) and PO₂ were measured, as were blood pressure and ECG.