Particulate Matter

Perspectives 1 is the first of a series produced by the HEI Health Review Committee to integrate findings across several HEI studies or entire research programs. The intent is to describe and interpret results bearing on important and timely issues for a broad audience in terested in environmental health.

Dr Checkoway and colleagues at the University of Washington tested the primary hypothesis that increases in daily fine particle levels were related to increased risk of out-of-hospital sudden cardiac arrest. Sudden cardiac arrest and questionnaire data, and exposure data were obtained from the Puget Sound Clean Air Agency (Seattle WA). The investigators used a case-crossover study design; for each case of sudden cardiac arrest, a time period when the person was disease free was selected as a matched "referent" period.

Dr. Mark Goldberg and his colleagues at McGill University conducted a time-series study in Montreal using available data from the Quebec Health Insurance Plan and mortality and air pollution data to better the understanding of the mortality-particulate association. Because of the comprehensive nature of this health insurance database, the investigators were able to link individual deaths in Montreal to medical information up to 5 years before death.

A Special Report of the Institute's Particle Epidemiology Reanalysis Project. The overall objective of this project was to conduct a rigorous and independent assessment of the findings of the Harvard Six Cities and American Cancer Society Studies of air pollution and mortality. This objective was met in two parts. In Part I: Replication and Validation, the Reanalysis Team led by Dr. Daniel Krewski sought to replicate the original studies via a quality assurance audit of a sample of the original data and to validate the original numeric results.