Study links London dirty air and teen blood pressure

The study showed air particles in car exhausts could raise blood pressure

Long-term exposure to air pollution is linked to higher blood pressure in London teenagers, a study says.

The findings showed a stronger association seen in girls caused by the tiny air pollution particles.

Scientists from Kings College London analysed data from more than 3,000 adolescents.

They also found exposure to high levels of nitrogen dioxide (NO2), a pollutant from diesel traffic, was associated with lowering their blood pressure.

NO2 is a pollutant from diesel traffic.

The results show the Particulate Matter (PM2.5) - tiny pollutants that come from car exhaust fumes, building, and industry materials - was associated with higher blood pressure across all ages, particularly among girls.

They analysed data from 3,284 adolescents, following up from ages 11-13 and 14-16 years old and examined the effects of air pollution on children attending 51 schools across London.

The pollution particles are small enough to be inhaled into the body and can make their way into the bloodstream, causing damage to blood vessels and airways.

The team said that based on its findings, published in the journal Plos One, more research was urgently needed to assess how air pollution may be affecting the cardiovascular health of children and adolescents.

'Green leafy vegetables'

Senior author Seeromanie Harding, a professor of social epidemiology at King's College London, says their study "provides a unique opportunity to track exposures of adolescents living in deprived neighbourhoods".

She added: "Given that more than one million under-18s live in neighbourhoods where air pollution is higher than the recommended health standards, there is an urgent need for more of these studies to gain an in-depth understanding of the threats to (and opportunities for) young people's development."

Co-author Dr Andrew Webb, also of King's College London, said: "The effect of NO2 on blood pressure is similar to what we and other researchers have observed previously after ingesting green leafy vegetables or beetroot juice.

"These are rich in dietary nitrate (NO3-) which increases circulating nitrite (NO2-) concentration in the blood and lowers blood pressure, an effect which may also be sustained over weeks or months with continued ingestion of nitrate-rich vegetables."

The researchers also found teenagers from ethnic minority groups were exposed to higher annual average concentrations of pollution at home than their white UK peers.

But, they added, the impact of pollutants on blood pressure did not vary according to ethnicity, weight, or economic status.

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