Research Reports

HEI’s mission is to provide credible science to support environmental regulations and other policy decisions. The results of each HEI-funded project undergo peer-review by outside scientists and the Health Review Committee. The HEI Research Reports contain the Investigator’s Report and the Review Committee’s evaluation of the study, summarized in a Commentary or short Critique.

ISSN 1041-5505 (print)        ISSN 2688-6855 (online) 

Research Report 64
Karam El-Bayoumy
Bruce E Johnson
Ajit K Roy
Pramod Upadhyaya
Syrus J Partian

Exposure to polycyclic aromatic hydrocarbons (PAHs) and their nitro-substituted derivatives (nitro-PAHs), products of incomplete combustion, is widespread. This is of concern because individual PAHs and PAH-containing mixtures cause tumors in animals and they are suspected to contribute to human cancer. To asses their carcinogenic potential in humans, biomarkers of PAH exposure that measure the internal dose or the effective dose need to be developed. Dr.

Research Report 65-I
Jerold A Last
Thomas R Gelzleichter
Jack R Harkema
Susan Hawk

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. The study of the effects of long-term ozone exposure on lung collagen, described in this report, was one of eight studies in a Collaborative Project supported by the NTP and the HEI. The others included studies of lung biochemistry, structure, and function, and one study of nasal structure and function. Dr.

Research Report 63
Jack D Hackney
Petros Koutrakis
Yukio Yanagisawa

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. Assessing the risk of adverse health effects from such exposures is difficult because only limited data are available on the actual ozone concentrations that people experience. Under the HEI ozone sampler program, three studies were designed to advance the development and testing of personal ozone samplers. The studies were conducted by Dr. Hackney and colleagues at Rancho Los Amigos Medical Center (Part I), Dr. Koutrakis and colleagues at the Harvard School of Public Health (Part II), and Dr. Yanagisawa from the Harvard School of Public Health (Part III). 

Research Report 62
Beatrice A Wittenberg
Jonathan B Wittenberg

Human exposure to carbon monoxide can occur from automobile emissions, industrial processes, sidestream or mainstream cigarette smoke, and poorly ventilated appliances such as space heaters and gas stoves. Most researchers consider the major mechanism for the toxicity of carbon monoxide to be its ability to compete with oxygen for binding to hemoglobin, the protein that transports oxygen through the bloodstream and releases it to cells and tissues.

Research Report 61
Roger W Giese
Paul Vouros

Both environmental and genetic factors are believed to contribute to the multistage process that results in carcinogenesis. Therefore, determining the health risks associated with exposure to known and suspected carcinogenic chemicals is essential for informed decision-making by regulatory agencies. Dr. Roger W. Giese and colleagues at Northeastern University developed sensitive and specific techniques for measuring polycyclic aromatic hydrocarbon (PAH)-DNA adducts, a class of DNA adducts associated with exposure to constituents of diesel emissions and other combustion products.

Research Report 60
Hanspeter Witschi
Michael A Breider
Hildegard M Schuller

Ozone and nitrogen dioxide are highly reactive oxidant gases that are derived from the combustion of fossil fuels and the atmospheric transformation of these combustion products. A major unanswered question is whether or not exposure to oxidant air pollutants contributes to lung cancer. Dr. Witschi and colleagues at the University of California at Davis examined whether exposure to ozone or nitrogen dioxide enhances the development of tumors induced by the chemical carcinogen diethylnitrosamine (DEN), particularly neuroendocrine tumors, in the respiratory tract of hamsters.

Research Report 56
Susan T Bagley
Linda D Gratz
David G Leddy
John H Johnson

Devices have been developed to reduce particle emissions from vehicles with diesel engines, such as a trap that filters the particles from the exhaust. Periodically, the trap is cleaned (regenerated) by electric heating, thereby burning the particles before they can clog the trap. There is concern that potentially harmful chemicals associated with the particles may be emitted from the trap during normal use and regeneration. Dr.

Research Report 58-I & II
Jonathan M Samet
William E Lambert

This publications contains two reports by Drs. Jonathan M. Samet, John D. Spengler, and colleagues, who conducted a prospective investigation of 1,205 healthy infants living in homes with gas or electric stoves in Albuquerque, NM. Nitrogen dioxide exposures were carefully estimated from repeated measurements in multiple locations in the subjects' homes throughout the entire 18-month observation period. Respiratory illnesses were monitored prospectively using a surveillance system based on daily parental diaries of respiratory signs and symptoms. Parental reports of illness episodes were validated in a subset of the population by comparison with clinical diagnoses and microbiological testing. Potential confounding factors that influence respiratory infections were reduced by selecting subjects whose parents did not smoke or intend to use day-care services outside the home.

Research Report 57
Arthur Penn

Carbon monoxide is a ubiquitous air pollutant. It is found in cigarette smoke and emissions from motor vehicles, industrial processes, and poorly ventilated combustion sources. Dr. Penn and his colleagues at New York University Medical Center sought to determine whether chronic exposure to ambient levels of carbon monoxide is also a risk factor for developing atherosclerosis because this disease is the leading contributor to deaths by heart attack and stroke in the United States.

Research Report 59
J Dennis McCool
Jonathan M Samet

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.