Long-term exposure to NO2 and PM10 and all-cause and cause-specific mortality in a prospective cohort of women.

ABSTRACT

We assessed whether long-term exposure to air pollution is associated with all-cause and cause-specific mortality during a period of declining particulate matter concentrations. Approximately 4800 women aged 55 years from North Rhine-Westphalia, Germany, were followed for up to 18 years. Exposure to air pollution was assessed in two ways (1) using the distance between the residential address and the nearest major road, as calculated from Geographic Information System data and (2) calculating 1-year average particulate matter concentrations below 10 µm (PM(10)) and nitrogen dioxide (NO(2)) levels using data from the nearest air-monitoring station data to the subjects' residences. Ninety-two per cent of all subjects lived in the same community during the entire follow-up period. Associations between mortality and exposure were assessed using Cox's proportional hazards models, including confounder adjustment. Sixteen per cent of women passed away during the follow-up period. An increase of 7 µg/m(3) PM(10) (IQR) was associated with an increased HR for all-cause (HR 1.15, 95% CI (1.04 to 1.27)), cardiopulmonary (HR 1.39, 95% CI (1.17 to 1.64)), and lung cancer mortality (HR 1.84, 95% CI (1.23 to 2.74)). An increase of 16 µg/m(3) (IQR) NO(2) exposure was associated with all-cause (HR 1.18, 95% CI (1.07 to 1.30)) and cardiopulmonary mortality (HR 1.55, 95% CI (1.30 to 1.84)). The association between cardiopulmonary mortality and PM(10) was reduced for the extended follow-up period, during which PM(10) concentrations (but not NO(2) concentrations) were lower. Living close to a major road was associated with an increased relative risk for all-cause, cardiopulmonary and respiratory mortality. These associations were temporally stable. Long-term exposure to ambient PM(10) and NO(2) was associated with increased mortality rates.