Publications

Dr. Fennell at the Chemical Industry Institute of Toxicology sought to develop new methods for improving the detection of formaldehyde-DNA adducts in exposed cells and tissues. The investigator treated formaldehyde-DNA adducts with sodium bisulfite, a compound that reacts with these adducts and traps them as stable compounds, and then tested different analytical techniques for separating and detecting the adducts. He exposed pure DNA, cell nuclei, and cells in culture to formaldehyde and treated them with sodium bisulfite under a variety of experimental conditions.

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.

HEI conducted the Environmental Epidemiology Planning Project in order to identify research needs and opportunities in selected areas of environmental epidemiology. Working groups in each selected area prepared documents composed of individually authored papers. The Planning Project documents were originally published in Environmental Health Perspectives (December 1993, Vol. 102).

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.

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.

Communication 2 provides information to decision makers on research that is potentially capable of narrowing uncertainties related to the health effects of specific air toxics. This report is based on the Mobile Air Toxics Workshop held in Monterey, CA, December 4–6 1992.

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.

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.

Ozone and nitrogen dioxide are significant outdoor and indoor air pollutants that can cause lung damage. Both are termed oxidant gases because the oxygen atoms they contain react with a variety of lung components and produce injury. Dr. Bruce Freeman and colleagues at the University of Alabama, Birmingham examined oxidant injury to alveolar epithelial cells and tested whether supplementing the levels of antioxidants would modify the cells' resistance to damage.

Drs. Chaitman and coworkers at the St. Louis University School of Medicine examined whether there is a link between carbon monoxide exposure and arrhythmias in subjects with coronary artery disease. 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. The investigators studied 25 men and 5 women, aged 45 to 77 years, all of whom were nonsmokers with stable coronary artery disease and who had moderate levels of ventricular arrhythmias.

HEI Communications 1 contains abstracts for six feasibility studies that were funded under RFA 89-2: Health Effects of Chronic Ozone Inhalation: Collaborative National Toxicology Program–Health Effects Institute Studies: Pilot Studies.

Dr. George Leikauf and coworkers at the University of Cincinnati Medical Center examined the mechanism by which aldehyde inhalation can alter breathing patterns and damage cells lining the airways. Emissions from motor vehicles using gasoline and diesel fuels add to the outdoor levels of aldehydes, including formaldehyde and acrolein, which are known irritants of the respiratory tract. The investigators prposed to examine whether airway constriction due to exposure to aldehydes is caused by damage to airway cells, by the entry of white blood cells into the lungs, or both.