Dieselgate and the unintended consequences of anti-idling drive


The Guardian, 25 March 2019:

In the US, the Dieselgate scandal has resulted in prosecutions against VW personnel and multibillion dollar fines (Where’s there’s smoke…, 22 March). In Europe, no one has been charged and nobody has gone to jail, though the EU commission has threatened action against the UK government for failing to prosecute VW.

Defeat devices result in higher emissions of nitrogen dioxide, but the real danger from a health perspective are small particulates, notably the ultra-fine nanoparticles that can penetrate tissue, reach a placenta and cross the blood-brain barrier. These are largely present in exhaust emissions, so while all vehicles generate particulates from tyres and brakes, researchers have demonstrated that medical effects such as low birth weight are tied more closely to exhaust particulates than to friction particulates. This is important as the government likes to pretend that all particulates are equivalent, regardless of the source. Thus its clean air strategy emphasises the contribution of secondary particulates generated from agriculture etc, even though these contain little in the way of ultra-fine particles. It is disheartening that the UK government seems more anxious to protect the interests of car manufacturers than the health of its own citizens, but this situation is likely to worsen post-Brexit.

Dr Robin Russell-Jones Scientific adviser

Geraint Davies MP Chair, All-party parliamentary group on air pollution

Dirty air and babies


The Times, 15 March 2019:

Sir, One neglected aspect of air pollution is its effect on birth weight (“Air pollution kills more people than boasting about freezing the fuel smoking”, Mar 13). A meta-analysis of 32 studies linking birth outcomes with the level of small particulates (PM2.5) concluded that each increase of 10g/m3 in PM2.5 lowers birthweight by 16 grams. Living in central London while pregnant is thus equivalent to smoking one cigarette a day.

In 2017 researchers from King’s College London showed that reductions in birth weight were tied more closely to exhaust emissions than to other types of particulates generated by traffic (eg, wear and tear on brakes and tyres) and not at all to noise pollution. During the Olympic Sir, Alice Thomson (Comment, Mar Games in 2008, the Chinese government made every effort to reduce pollution levels in Beijing, and birth weight increased. The maximum benefit was for women in the eighth month of pregnancy, a period of maximum foetal growth.

Low birth weight is important because it is linked to a host of adverse outcomes in later life, including lower IQ. The British government could do far more to mitigate these effects. Instead of boasting about freezing the fue escalator for the past nine years, the chancellor should increase the tax on diesel, introduce a diesel scrappage scheme and bring forward the phase-out date for fossil fuel vehicles from 2040 to 2030.

Dr Robin Russell-Jones, FRCP, FRCPath, scientific adviser to the all-party parliamentary group on air pollution

Geraint Davies, MP
chairman, APPG on air pollution

Gas strategy in the UK is wrongheaded


The Guardian, 12 March 2019:

It is no surprise that the government’s strategy on fracking has been deemed unlawful (Fracking guidance illegally ignores climate change, 7 March). Gas may be more fuel efficient than coal when burnt, but shale gas is 95% methane, and methane is a powerful greenhouse gas. According to the IPCC it has a global warming potential (GWP) 85 times greater than carbon dioxide over a 20-year timeframe. Misleadingly, HMG have relied on an obsolete figure of 36 for the GWP of methane, dating back to 2013.

Methane levels plateaued in the late 1990s, but have started to increase again over the past decade and have now reached 1,900 parts per billion, against a pre-industrial level of 700. Fracking is the obvious culprit. Satellite data over the US has shown that methane leakage exceeds 5% of shale gas production, an observation that fits with more recent studies by Nasa showing that fossil fuels are the major contributor to the continuing rise in atmospheric methane.

Despite this evidence, the government’s energy strategy is to forge ahead with fracking while reducing environmental safeguards and providing tax incentives for its development. The government claim that gas is better than coal from a climate change perspective is only sustainable if fugitive emissions of methane are ignored. Let us hope that the high court judgment means that fracking will be abandoned in the UK as it has been elsewhere in Europe.

Dr Robin Russell-Jones Scientific adviser to the all-party parliamentary group on air pollution (APPG)
Geraint Davies MP Chair, APPG