EFFECTS OF AMBIENT PARTICULATE MATTER AND OZONE ON DAILY MORTALITY INROTTERDAM, THE NETHERLANDS

The association between daily variations in all-cause mortality from 1 983-1991 in Rotterdam, the Netherlands, and ambient air pollution was investigated. Twenty-four-hour average concentrations of total suspend ed particulates, Black Smoke, ozone, sulfur dioxide, and carbon monoxi de were available on a daily basis. Every other day, total iron conten t in total suspended particulates samples was available. Poisson regre ssion analysis was used to study associations between air pollution an d mortality; generalized additive models were used to adjust for confo unders (e.g., seasonal trends, weather). Daily mortality was associate d most consistently with previous-day concentrations of total suspende d particulates (relative risk = 1.05 for a change of 91 mu g/m(3)) and ozone (relative risk = 1.06 for a change of 67 mu g/m(3)) Total iron was associated less consistently with mortality than total suspended p articulate mass was. The associations of mortality with ozone and tota l suspended particulates were independent of sulfur dioxide and carbon monoxide. The relative risks of total suspended particulates and part icularly ozone were higher for subjects older than 78 y. The relations hip between mortality and ozone did not deviate significantly from lin ear. The relationship between mortality and total suspended particulat es was linear below 100 mu g/m(3) and leveled off at higher concentrat ions. If a threshold exists for the effects on mortality of these comp onents, it exists at very low levels.