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The association between air pollution exposure and hospitalization for cardiovascular events has been reported in several studies, but with conflicting results. Some studies found an increased risk of myocardial infarction (MI) when exposed to high levels of air pollution whereas other studies showed no significant effect. So, it remains controversial as to whether there is a link between air pollution and MI. A team of investigators could find no meta-analysis to date analyzing the impact of the main air pollutants: ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter within 10 microns and 2.5 microns in diameter. Thus, they conducted a systematic review and meta-analysis in hopes of resolving this controversy. After a detailed screening of 114 studies, investigators identified 33 studies suitable for meta-analysis. All of the major air pollutants except ozone were significantly associated with increased risk of MI. The increased risk was significant but not large, ranging from 1.007 to 1.054. However, the investigators noted that the population attributable fraction ranged from about 0.7% to 5.1%. This measure -- which often guides policy makers in planning public health interventions -- has been described as the reduction in incidence that would be observed if the population were entirely unexposed, compared with its current (actual) exposure pattern. Given that the majority of the population is exposed to air pollution, the authors emphasized that the effects seen in this study are not negligible. Therefore, the data suggest that efforts to improve air quality and reduce the impact of air pollution are needed and would likely have health benefits that would include a reduction in cardiovascular events. |
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