Key points:
- A study links particulate matter to high blood pressure in developing adolescents aged 11 to 16.
- Meanwhile, nitrogen dioxide was associated with lower blood pressure.
- 98 percent of schools in London are in areas that exceed WHO pollution limits
A study conducted in London of adolescents aged 11 to 16 found a correlation between long-term exposure to PM2.5 and higher blood pressure, especially in girls. The same findings also showed that exposure to high levels of nitrogen dioxide lowered blood pressure.
While the effect of air pollution on adult blood pressure is well known, few longitudinal studies have examined adolescents.
The paper, published in PLOS One by researchers from King’s College London, assessed 3,284 children attending 51 schools across the capital. The age range—11 to 16—was purposeful as that period is particularly important as adolescents continue to grow and develop. Negative effects on their organs at this stage could lead to life-long complications.
The results show particulate matter (PM2.5), tiny pollutants in the air that come from car exhaust fumes and industrial materials, were associated with higher blood pressure across all ages, particularly among girls. High blood pressure puts adults at greater risk of hypertension, heart attacks and strokes.
Interestingly, nitrogen dioxide (NO2), a pollutant predominantly caused from diesel traffic, was associated with lower blood pressure. Previous research has shown NO2 may have damaging effects on the respiratory system, but the impacts of the pollutant on the cardiovascular system is less clear. However, a recent study from this group found that sitting next to a lit gas acutely lowers blood pressure in healthy adult volunteers,
A 2021 study found that 3 million children across England go to schools in areas exceeding WHO limits on PM2.5, and 98 percent of schools in London are in areas exceeding World Health Organisation pollution limits.
“The findings highlight the potential detrimental role of exposure to higher concentrations of particulate matter on adolescents' blood pressure levels,” said corresponding author Alexis Karamanos from King’s College London. "Further studies following the same adolescents over time in different socio-economic contexts are needed to understand whether and how exposure to higher pollutant concentrations may affect differently the cardiovascular health of children and adolescents.”