A study of adolescents aged 11-16 in London has found long-term exposure to PM2.5 is associated with higher blood pressure, with stronger associations seen in girls.
Findings also show that exposure to high levels of nitrogen dioxide is associated with lower blood pressure in this group.
The paper, published in PLOS One by researchers from King’s College London, examines the possible effects of long-term exposure to air pollution in children attending 51 schools across the capital.
The period between 11-16 years of age is particularly important as adolescents continue to grow and develop. Negative effects on their organs at this stage could lead to life-long complications.
Researchers analyzed data of 3284 adolescents and followed up from ages 11-13 and 14-16 years old. They measured systolic and diastolic blood pressure at participants schools.
The results show Particulate Matter (PM2.5), tiny pollutants in the air that come from car exhaust fumes, building and industry materials, were associated with higher blood pressure across all ages, and were particularly felt among girls (a μg/m3 increase in PM2.5 was associated with 1.34 mmHg increase in systolic BP for girls and 0.57 mmHg increase in systolic BP for boys). Higher blood pressure can raise the risk of hypertension, heart attacks and strokes in adulthood.
Interestingly, nitrogen dioxide (NO2), a pollutant which in London is predominately due to diesel traffic, was associated with lower blood pressure. Systolic blood pressure decreased by ~5 mmHg for boys and ~8 mmHg for girls when NO2 almost doubled from a low to a high concentration.
