Multipollutant Mixtures

Research Report 139 describes a study in the Netherlands using data from the ongoing Netherlands Cohort Study (NLCS) on diet and cancer. The study is one of the first to systematically assess longer term exposure and mortality in a well characterized European population; it followed a pilot study of 5000 adults randomly selected from the NLCS cohort conducted by the same team of investigators. For the current study, Dr.

This report contains two studies, by Drs. Annette Peters and Douglas Dockery. Dr. Peters and her colleagues evaluated the association between nonfatal myocardial infarction (MI) and exposure to particulate matter just prior to the event. She asked 691 patients in hospitals in Augsburg, Germany who survived an MI to provide hourly details about their activities 4 days before MI onset. The investigators used a case-crossover analysis to determine whether exposure to pollutants was associated with onset of MI. Dr. Dockery and colleagues assessed the correlation between short-term increases in ambient concentrations of particulate matter and the risk of possibly life-threatening arrhythmias in patients with implanted cardioverter defibrillators (ICDs). The investigators studied 195 patients from Boston, MA who had either single or dual-chamber ICD's and used logistic regression models to determine whether exposure to air pollutants was associated with arrhythmias.

Dr. Navidi and colleagues at the University of Southern California discussed the development of three sophisticated statistical methods that would improve the estimates of the health effects of air pollution obtained from epidemiologic studies. First, they took a standard case-crossover design and introduced a bidirectional element where control data were obtained both before and after the health event of interest.

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.