Publications

A Special Report of the Institute's Oxygenates Evaluation Committee. Oxygenated fuel (usually referred to as oxyfuel) was formulated to reduce carbon monoxide emissions and contains at least 2.7% oxygen by adding methyl tert-butyl ether (MTBE) or ethanol. Reformulated gasoline was formulated to help reduce ground-level ozone concentrations and contains at least 2% oxygen, has a reduced content of benzene and other aromatic compounds, and produces limited emissions of total air toxics. The introduction of fuels containing oxygenates elicited concerns from workers and the general public in some areas, including reports of unpleasant odors, headaches, or other symptoms attributed to the fuels, and questions about their effects on the cost of gasoline, the performance of engines, and fuel economy. This Special Report summarizes an intensive review of (1) the existing science of the health effects of oxygenates, (2) the risk evaluations done by the EPA in 1993 and 1994, and (3) in a qualitative way, the health effects of exposure to the new additives as they relate to the health effects of other pollutants whose levels in emissions change when fuels containing oxygenates are used.

In Part III of this study, Dr. Belinsky and his associates at the Lovelace Biomedical and Environmental Research Institute examined lung tumors from rats that had inhaled high concentrations of diesel engine exhaust or carbon black particles (see Part I by Dr. Joe Mauderly). The investigators applied molecular biology techniques to measure mutations in selected genes in the DNA from the tumors.

Dr. Beland and his associates at the University of Arkansas School of Medical Sciences developed an assay to measure mutations induced by dinitropyrenes, a class of diesel engine exhaust, in rats. The investigators analyzed the mutations in a selected gene in spleen T lymphocytes from rats treated with 1,6-dinitropyrene under conditions that induced lung tumors at the highest dose tested. They also examined DNA adduct levels in lung and liver tissues and in spleen lymphocytes and white blood cells.

The Phase I.A Report of the Particle Epidemiology Evaluation Project. The Health Effects Institute began the Particle Epidemiology Evaluation Project in 1994 to evaluate the emerging epidemiologic evidence of a relation between particulate air pollution and daily mortality. In Phase I.A, Drs. Jonathan M. Samet and Scott L. Zeger and their colleagues at the Johns Hopkins University School of Hygiene and Public Health (1) reconstructed from original sources the data set for Philadelphia used in earlier studies and confirmed previous numerical results from analyzing these data; (2) developed an analytic approach (including new statistical methods) based on the Philadelphia data set; and (3) applied this approach to data sets for six locations: Philadelphia; Utah Valley; St. Louis, MO; Eastern Tennessee; Birmingham, AL; and Santa Clara County, CA.

A Special Report of the Institute's Diesel Working Group. Diesel engine emissions have the potential to cause adverse health effects, including cancer and other pulmonary and cardiovascular diseases. However, it is difficult to distinguish the potential health risks attributable to exposure to diesel exhaust from those attributable to other air pollutants. For over a decade, HEI has supported a broad-based research program to evaluate the health risks of diesel emissions, including investigations of carcinogenesis, modeling studies, and emissions characterization. The purpose of this Special Report is to examine what is known, not known, and still uncertain about the health risks of exposure to diesel emissions.

Ozone is a highly reactive gas that is a pervasive air pollutant at ground level. It is a major component of urban smog, forming when emissions from mobile and industrial sources interact with sunlight. In this report, two of studies and in the NTP/HEI Collaborative Ozone Project, were conducted to determine whether prolonged inhalation of ozone produces lasting effects on lung structure, potentially contributing to or aggravating chronic lung disease. Drs. Chang and Pinkerton and their respective colleagues investigated the effects of this prolonged ozone exposure on respiratory tract structure in healthy male and female F344/N rats. 

In two separate studies, Drs. Koenig and Utell examined the effects of exposing healthy subjects and subjects with asthma to combined oxidant and acid pollutants. Each team of investigators conducted studies in which human volunteers received either combined or sequential exposures to oxidant gases and acid aerosols and standard pulmonary function tests were performed and symptoms were recorded. Dr. Koenig and colleagues exposed 28 adolescents with asthma to varying concentrations of ozone, nitrogen dioxide, and sulfuric acid. Dr. Utell and colleagues examined the effects of sequential exposures to sulfuric acid and ozone on pulmonary function in 30 subjects with asthma and 30 healthy subjects between the ages of 18 and 45. 

Ozone is the major pollutant in smog. It is formed by complex photochemical reactions between nitrogen oxides and volatile organic compounds in the presence of sunlight. Motor vehicle and industrial emissions are prominent sources of these compounds. Peak atmospheric ozone concentrations generally occur during the summer months because the photochemical reactions that produce ozone are enhanced by sunlight and high temperature.

Ozone is a highly reactive gas that is a pervasive air pollutant at ground level. It is a major component of urban smog, forming when emissions from mobile and industrial sources interact with sunlight. Prolonged ozone exposure may injure respiratory tissue, leading to the development or exacerbation of chronic lung diseases such as fibrosis or emphysema. An excess of connective tissue can lead to fibrosis and changes in connective tissue are believed to be an underlying cause of emphysema. Dr.

Dr. James Ultman and colleagues at Pennsylvania State University used a fast-responding ozone measurement system, which they had developed with previous HEI support, to noninvasively measure the absorption of inhaled ozone in different regions of the respiratory tract of healthy adult men. While the subject was breathing through the measurement apparatus, a narrow 10-mL bolus of ozone was introduced into the inhaled air at a predetermined point.

This report describes the quality assurance and quality control program developed for the previously reported epidemiologic study of nitrogen dioxide (NO₂) and respiratory illness in children (Health Effects Institute Research Report 58, Parts I and II). The specific aims of the program were to make certain that data were sufficiently accurate, complete, verifiable, and retrievable.

High doses of inhaled diesel engine exhaust produce lung tumors in laboratory animals and may cause cancer in humans. Nitropyrenes are products of diesel engine exhaust and can be activated by the body\'s metabolism to form highly reactive products that interact with DNA to form DNA adducts. The adducts can interfere with the normal processes of DNA replication and can lead to genetic mutations that may result in carcinogenesis. Dr.