Association Between Blood Pressure and Particulate Air Pollution in School Children of Lahore, Pakistan

Abstract

Background/Aims: There is no general agreement as to whether particulate air pollution increases arterial blood pressure (BP) in adults and no studies so far have been conducted in children. We examined the relation between blood pressure and particulate air pollution (particulate matter PM2.5 ) in healthy school children of Lahore (Pakistan). We recruited 179 subjects (mean age, 9.8 yr; 45% girls) from 2 urban schools in a low (n = 79) and a high (n = 100) pollution area. Methods: BP was measured, after 5 minutes of sitting rest, 5 times consecutively using an automated device placed around the left arm. Particulate air pollution was measured at the school sites with a laser-operated device (Metone Aerocet 531), which was standardized against European air pollution monitoring stations. Spirometry was also performed. Results: Mean systolic/diastolic BP was 108.2/67.1 mmHg in children living in the less polluted area (mean, 24 hours PM2.5 28.7 [ SD 9.7 ] g/m3] vs. 115.6/70.7 mm Hg) in the high polluted area [ mean, 24 hours PM2.5 163.0 (SD 34.5) g/m3] . The mean differences in systolic BP [7.4 mm Hg; P = < 0.0001 and in diastolic BP [ 3.6 mm Hg; P = 0.002 ] were independent of age, gender, body mass index, socioeconomic status and the urinary concentrations of sodium, potassium, and calcium. There were no differences in spirometric indices. Conclusion: Urban school children living and going to school in an area with high levels of particulate air pollution had substantially higher systolic and diastolic BP than those from a less polluted urban area. These findings might have clinical relevance for their future cardiovascular health.