Figuring out true levels of nitrogen dioxide pollution

• OVER the past few months your newspaper has published numerous claims about air pollution in the Highbury area and poll results which show that people “feel” that air pollution has risen.

Feelings are important but so are data. As an exercise for some of our students, we made diffusion tube measurements of nitrogen dioxide pollution.

Our students placed clusters of six diffusion tubes close to the entrance to each of four local primary schools.

The measurements were made in November-December following Department for Environment, Food and Rural Affairs protocols.

The results, given in μg/m3 or micrograms (one-millionth of a gram) per cubic metre air, are as follows:

Ambler PS (Romilly Road entrance) 32±4

Ambler PS (Blackstock Road entrance) 48±4

Gillespie PS 32±2

Saint Joan of Arc PS 38±2

Drayton Park PS 36±2

As can be seen the Blackstock Road entrance at Ambler PS remains above the legal limit of
40 μg/m3, but this is substantially below the levels that we and others, including Islington Council, have measured over the past 10 years.

It is clear that there is more work to do to bring down this type of pollution, but it also confirms that levels have not risen as a result of the introduction of the LTN, low traffic neighbourhood.

PROFESSOR ANDREA SELLA
Department of Chemistry
University College London