Investigating the association between ambient particulate matter (PM) exposure and blood pressure values: Results from the link between the Portuguese Health Examination Survey and air quality data.

Introduction And Objectives: High blood pressure (BP) remains a major modifiable cardiovascular (CV) risk factor. Several epidemiologic studies have been performed to assess the association between air pollution exposure and this CV risk factor but results remain inconsistent. This study aims to estimate the effect of short-term PM exposure (average previous three-day concentration) on diastolic (DBP) and systolic (SBP) blood pressure values of the resident mainland Portuguese population.

Methods: Our study was based on available DBP and SBP data from 2272 participants from the first Portuguese Health Examination Survey (INSEF, 2015) living within a 30 km radius of at least one air quality monitoring station, with available measurements of particulate matter with an aerodynamic equivalent diameter ≤10 μm (PM). We used data from the air quality monitoring network of the Portuguese Environment Agency to obtain the individual allocated PM concentrations. Generalized linear models were used to assess the effect of PM exposure on DBP and SBP values.

Results: No statistically significant association was found between PM exposure and both DBP and SBP values (0.42% DBP change per 10 μg/m of PM increment (95% confidence interval (CI): -0.85; 1.70) and 0.47% SBP change per 10 μg/m of PM increment (95% CI: -0.86; 1.79)). Results remain unchanged after restricting the analysis to hypertensive or obese participants or changing the PM assessment methodology.

Conclusions: In view of the PM levels observed in 2015, our results suggests that exposure to PM concentrations have a small or no effect on the blood pressure values. Other air pollutants and mixtures of pollutants that were not included in our study should considered in future studies.