AIR POLLUTION CARDIOVASCULAR EFFECTS.

The size of air pollution effect on cardiovascular diseases use to be smaller than that observed for respiratory diseases. Myocardial infarction (MI) is an acute and grave cardiovascular disease and, in general, leads patients to admissions at the intensive care units (ICU). Few MI cases are initially admitted at the infirmaries. In order to check whether estimates of air pollution effects on MI morbidity are modified by the source of health information we performed a time series study using two outcomes: MI admissions at the infirmaries and MI admissions at the ICU both for people older than 64 years of age, in hospitals of the Brazilian Public Health System in São Paulo City. We adopted generalized linear models controlling for seasonality (long and short-term trends) and weather variables using a semi-parametric smoother. The eight days cumulative effects of air pollutants were assessed using third degree polynomial distributed lag models. Our results showed that almost 70% of the daily hospital admissions due to Ml are done at the infirmaries. Despite of that, the effects of air pollutants on MI were bigger for ICU admissions. All pollutants were positively associated with the adopted outcomes but SO2 presented the strongest and statistically significant one. An interquartile range increase on SO2 concentration was associated with increases of 26% (95% CI 10;42) and 3% (95% CI -5;11) on ICU and infirmary MI admissions, respectively. We can suppose that, maybe, there is a misclassification of the MI infirmary admissions leading to overestimated numbers. Also, its clear that, despite the absolute number of events, ICU admissions data provides a more adequate estimate of the size of air pollution effects on MI admissions. Study funded by CEACL-CLIMED/UNIFESP and UNISA. [ABSTRACT FROM AUTHOR]