gms | German Medical Science

Background: Daily variations in ambient air pollution have been consistently associated with increased daily mortality around the world. This study aimed at assessing the effects of ambient air pollution on daily mortality in Erfurt after the German unification, when air quality improved.

Material and Methods: Daily mortality counts were obtained in Erfurt between October 1991 and March 2002. Data on gaseous pollutants, particulate matter smaller than 10 µm (PM10), and meteorology were obtained from state-run networks sites. Particle size distributions were measured at our research monitoring site from September 1995 to March 2002. Particulate matter smaller than 2.5 µm (PM2.5) was calculated based on these data. Data on changes in energy consumption, car fleet composition and population were collected from local authorities. Associations were analyzed using semiparametric Poisson models. Variations of the effect estimates over time were evaluated in Bayesian hierarchical time-varying coefficient models.

Results: Results point to associations between mortality and CO, NO2, and UFP with a 3 to 4 days delay. The increased risk for mortality ranged between 1.6% and 2.9% for an interquartile range increase of the three pollutants. No associations were observed for PM10 and PM2.5. Effect estimates exhibited long-term changes over time (CO, UFP, PM2.5, PM10) and seasonal variations (all pollutants except CO). Changes in source characteristics were not able to explain these observations in a straight forward manner. However, the results suggest that measures such as the introduction of 3-way catalytic converters and replacing of coal by natural gas may have been beneficial.

Conclusion: Economic and political changes as well as adoption of new technologies in East Germany have resulted in clear improvements in ambient air quality. Regression results indicate an elevated mortality risk from short-term exposure to traffic-related air pollutants whose magnitude may change over time along with changing air pollution patterns.

Research described in this abstract was supported by the Health Effects Institute (Boston, MA, USA), an organization jointly funded by the United States Environmental Protection Agency (EPA) (Assistance Agreement R82811201) and automotive manufacturers. The contents of this abstract do not necessarily reflect the views and policies of EPA, or motor vehicle and engine manufacturers.