Boris Johnson and London’s toxic air

http://www.theguardian.com/environment/2016/mar/01/boris-johnson-and-london-toxic-air

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Despite claims in your editorial (Boris Johnson leaves London breathing uneasy, 24 February), London’s air quality is improving as a direct result of the many bold measures introduced by the mayor to reduce health impacts. Since 2008 these have helped halve the number of Londoners living in areas exceeding legal limits, with the greatest improvements by roads, where people are most exposed. We know this as the mayor and boroughs work with many organisations, including King’s College, to deliver a multitude of testing and monitoring systems that are some of the most comprehensive in the world.

The editorial failed to mention that no other country in the world has proposed an ultra-low emission zone with standards as tight as the mayor’s. However, its introduction requires a measured approach to take into account the many people who bought vehicles in good faith and have subsequently been let down by Brussels’ historic failure to regulate vehicle emissions and approach to dieselisation.

The truth is if the rest of the UK and the EU implemented London’s hard-hitting programme of measures, the capital’s air would improve significantly. From setting age limits on taxis to a major upgrade of London’s bus fleet, the mayor’s greatest priority has been to protect the wellbeing of Londoners. But he and indeed any mayor cannot fight pollution alone.

At City Hall we’ll continue to lobby for the strong support of the government and the EU to win this battle and target the enormous amount of toxic air transported into London from overseas.Matthew PencharzDeputy mayor for environment and energy

• Your editorial underlines the indifference of the mayor of London to air pollution which, according to the Royal College of Physicians and the Royal College of Paediatrics and Child Health, causes 40,000 premature deaths annually in the UK. But there are equally serious effects at the other end of life.

Small particulates (PM2.5) can cross the placental barrier and are associated with a number of negative outcomes including low birth weight. The WHO limit for small particulate is 25 micrograms per cubic metre of air, a level that is regularly exceeded in most UK cities. However, foetal effects are without threshold and are seen at levels below 25 micrograms.

It is not just the overall weight that is affected. Brain development is also compromised, and several studies link exposure to particulates, and oxides of nitrogen (NOx) to delayed neurocognitive development and lower IQ (See pages 34-41 of the RCP report).

Toxic metals like lead and small particulates like PM2.5 can cross the placental barrier, designed to protect the unborn foetus from harm. Our negligence has resulted in the replacement of one potent neurotoxin, lead, with another, PM2.5, derived almost exclusively in places like London from diesel-powered vehicles. It is equally dangerous, equally insidious and equally deserving of a total ban.Dr Robin Russell-Jones(Former chair, Campaign for Lead-Free Air)Stoke Poges, Buckinghamshire

• Criticism of my report on diesel car technology by an interviewee in your report (Diesel cars may be worse than petrol for carbon emissions, report claims, theguardian.com, 19 February) was based on claims I did not make.

My paper clearly pointed out that black carbon emissions have decreased for new diesel cars – if diesel particulate filter (DPF) is working properly.

But that’s a big if. Filter clogging and filter removal are significant compromising factors. In 2014 real-world testing in Germany pointed to a rate of 9% for filter dysfunction/removal, while French tests found that 75% of diesel cars had problems leading to higher air pollution levels.

In the UK the removal of DPFs is still not illegal. According to a 2015 report, more than 1,000 garages in Britain offer DPF removal, and sadly, a number of writers in car magazines continue to advocate this course of action. The UK is not alone. (Garages happy to remove DPFs can easily be found in Germany, Spain and Ireland, among other EU member states, with only the Madrid authorities showing some efforts to clamp down on it.) In short, the theoretical capacity of diesel emissions reduction equipment is one thing; the real-world situation is another.

What we know for sure is that electric mobility powered by renewables offers the best opportunity to radically reduce transport emissions, both from the perspective of air quality and climate change.

European governments can support this transition by removing financial incentives if and when they favour diesel. Examples include lower taxes for diesel fuel, registering or owning diesel cars, and for company cars that run on diesel.Professor Eckard HelmersTrier University of Applied Sciences, Germany

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