Air Pollution and Mortality: Results from Santiago, Chile

May 1995 The relationship between particulate air pollution and premature death in Santiago, Chile is found to be very similar to results from industrial countries. Heavy outdoor pollution is found in developing country cities such as Jakarta, Katowice, Mexico City, and Santiago. But most epidemiological studies of dose-response relationships between particulate air pollution (PM10) and premature deaths are from Western industrial nations. This study of such relationships in developing countries by Ostro, Sanchez, Aranda, and Eskeland fills an important gap. It is also one of the few based on monitored PM10 values, or small particles, which is likely to be a more relevant measure of exposure to air pollution than the more traditional measure of total suspended particulates. Over several years, daily measures of ambient PM10 were collected in Santiago. Data were collected for all deaths, as well as for deaths for all men, all women, and all people over 64. Deaths from respiratory and cardiovascular disease were recorded separately, and accidental deaths were excluded. Multiple regression analysis was used to explain mortality, with particular attention to the influence of season and temperature. The association persists after controlling for daily minimum temperature and binary variables indicating temperature extremes, the day of the week, the month, and the year. Additional sensitivity analysis suggests robust relationships. A change equal to 10-microgram-per-cubic-meter in daily PM10 (about 9 percent) averaged over three days was associated with a 1.1 percent increase in mortality (95 percent confidence interval: 0.6 to 1.5 percent). Death from respiratory and cardiovascular disease was more responsive to changes in PM10 than total mortality was. The same holds for mortality among men and mortality among individuals older than 64. The results are surprisingly consistent with results from industrial countries. This paper -- a product of the Public Economics Division, Policy Research Department -- is part of a larger effort in the department to analyze environmental policies. A shorter version will be published in Journal of Exposure Analysis and Environmental Epidemiology. The study was funded by the Bank's Research Support Budget under the research project Air Pollution and Health Effects in Santiago, Chile (RPO 678-48).