How to win the war on air pollution | Letters

Damian Carrington is half right (The war against air pollution has begun – and it will be fought in cities, 13 February) in that cities bear a terrible burden from air pollution and municipal action is critical to address it. However, city governments cannot succeed alone. Much of urban pollution stems from outside city limits and significant progress will only be achieved with policies that also require national, regional and even international commitment.

A significant part of city air pollution drifts in from regional sources like wood-burning rural households, coal-fired power plants, industries and the open burning of agricultural waste and rubbish. Commuters driving in from car-centric suburbs and transport between cities contribute to urban congestion and pollution too, stymying smart city initiatives like investments in public transportation and safer streets for walking and cycling.

We know what works. Cities must enact new policies like those mentioned. But, as important, national and state governments must ensure access to clean household energy and enforce limits on emissions from power stations, industry, open burning and other sources. Policies are also needed to support regional public transit, set standards for low vehicle emissions and low sulphur content in petrol and diesel. Until then, a large part of the air quality – and health – of cities will be at the mercy of their neighbours and the wind that carries their pollution.
Tom Matte
Vice-president for environmental health, Vital Strategies, New York

• Air pollution is not just a London problem (Editorial, 17 February). Of the 43 zones currently monitored in the UK, 38 fail EU standards for NO2, so any strategy has to be nationwide and not left to individual councils.

The most likely government response is an extension of clean air zones, but there are serious doubts as to whether this will improve public health. First, designating certain areas as clean does nothing to reduce total emissions; it merely diverts them elsewhere. Second, the health effects of NO2 and particulates are without threshold, so reducing levels below an arbitrary limit may make sense politically, but will have little effect biologically. Third, the projected improvement in air quality is predicated upon new vehicles producing less NO2 in line with stricter EU vehicle emission tests, but we already know that emissions of NO2 “on the road” are four to five times greater than in laboratory tests, a discrepancy that even applies to the latest Euro 6 engines. Finally, studies of London schoolchildren showed no improvement in lung function after three years living in a low-emission zone.

As your leader proposes, we are in urgent need of a new Clean Air Act that hastens the demise of diesel and other highly polluting technologies, something the government could and should have championed more than 20 years ago.
Dr Robin Russell-Jones
Former chair CLEAR, Campaign for Lead Free Air, Stoke Poges, Buckinghamshire

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