An evaluation of the health benefits achieved at the time of an air quality intervention in three Israeli cities.

BACKGROUND: The statistical association between increased exposure to air pollution and increased risk of morbidity and mortality is well established. However, documentation of the health benefits of lowering air pollution levels, which would support the biological plausibility of those past statistical associations, are not as well developed. A better understanding of the aftereffects of interventions to reduce air pollution is needed in order to: 1) better document the benefits of lowered air pollution; and, 2) identify the types of reductions that most effectively provide health benefits.
METHODS: This study analyzes daily health and pollution data from three major cities in Israel that have undergone pollution control interventions to reduce sulfur emissions from combustion sources. In this work, the hypothesis tested is that transitions to cleaner fuels are accompanied by a decreased risk of daily cardiovascular and respiratory mortalities. Interrupted time series regression models are applied in order to test whether the cleaner air interventions are associated with a statistically significant reduction in mortality.
RESULTS: In the multi-city meta-analysis we found statistically significant reductions of 13.3% [CI -21.9%, -3.8%] in cardiovascular mortality, and a borderline significant (p=0.06) reduction of 19.0% [CI -35.1%, 1.1%] in total mortality.
CONCLUSIONS: Overall, new experiential evidence is provided consistent with human health benefits being associated with interventions to reduce air pollution. The methods employed also provide an approach that may be applied elsewhere in the future to better document and optimize the health benefits of clean air interventions.