Fine particulate matter and ischemic heart diseases in relation to sex. An ecological time series study

BACKGROUND: Exposure to some air pollutants is associated with cardiovascular diseases. The objective of this study was to quantify the effect of exposure to fine particulate matter in hospitalizations due to ischemic heart disease and the costs to the healthcare system. DESIGN AND SETTING: Time-series ecological study conducted in Taubate, Brazil. METHODS: Data on hospitalizations due to ischemic heart diseases (ICD I-20 to I-24) in the municipality of Taubate (SP), Brazil, among adults of both sexes aged 40 years and over, from August 2011 to July 2012, were obtained from DATASUS. Fine particulate matter (PM2.5) concentrations were estimated from a mathematical model. Poisson regression was used in statistical analyses to estimate the relative risks of exposure to PM2.5 for both sexes and after stratification according to sex. The excess of hospitalizations and consequent excess expenditure for the healthcare system were calculated. RESULTS: There were 1040 admissions, among which 382 had ischemic heart diseases (257 males). The mean PM2.5 concentration was 13.2 mu g/m(3) (SD = 5.6). Significant effects from exposure were noted 4 and 5 days after exposure (lag 4 and lag 5) for both sexes and for male sex; for female sex, the effect was 2 days after exposure (lag 2). There were 59 excess hospitalizations for an increase in PM2.5 concentration of 5 mu g/m(3) and excess expenditure of US$ 150,000 for the National Health System. CONCLUSIONS: An excess of hospital admissions due to ischemic heart disease, with excess expenditure, was identified consequent to PM2.5 exposure.