December 1, 2016

expert reaction to draft nice guideline on outdoor air pollution and health

The National Institute for Health and Care Excellence (NICE) have drafted guidelines on outdoor air pollution and health. These comments accompanied a press briefing.

Prof Ian Colbeck, Professor of Environmental Science, University of Essex, said:

“This is a timely report given High Court’s ruling that the Government’s existing plans to improve air quality are unsatisfactory. However the recommendations in the report focus on local government at a time when their budgets are constantly being cut.

“Overall the recommendations aren’t particularly novel.  There are a number of apps which provide real time air pollution information and so why not incorporate this into satellite navigations systems to plan journeys which avoid roads with poor air quality.”

Prof Jonathan Grigg, Professor of Paediatric Respiratory and Environmental Medicine, QMUL, said:

“Although the report clearly points the finger at emissions from diesel vehicles, for example noting that “the contribution of diesel cars to nitrogen dioxide pollution is substantial” – and that “no decrease in concentrations of nitrogen oxides are due to the difference in emissions during test procedures compared with ‘real world’ driving, combined with an increase in the number of diesel vehicles on the road”, the report gives the impression that targeting diesel is not particularly effective.

“While it indeed may be true that local interventions are not particularly effective in reducing exposure to diesel soot and gases, the report did not consider whether the current National Plan (Improving air quality in the UK Tackling nitrogen dioxide in our towns and cities UK overview document, December 2015) will deliver major reductions in diesel emissions from all roads across the UK. This is important since, without an effective national diesel policy (such as a scrappage scheme), local initiatives are either likely to fail to deliver, or at best make small changes in exposure with limited health benefits.”

Prof Richard Skeffington, Department of Geography and Environmental Science, University of Reading, said:

“In spite of the general title, the Guideline only covers road transport-related pollution.  NICE has considered a number of actions which might lead to improved air quality and made recommendations for their implementation. The actions have been assessed on the basis of a structured and systematic review of the available evidence by expert committees, in line with NICE’s method of working. NICE guidance is aimed at public health practitioners and managers, particularly in local authorities and the NHS, hence there is not much in the report covering actions individuals can take, or any assessment of large-scale government initiatives such as incentives to switch from road to rail travel.

“Most of the actions discussed are already being implemented at least in places – there is little new or radical here. For instance it is suggested to take air quality issues into account in developing local plans (already required in England and Wales); and to train bus drivers in fuel-efficient driving and procure low emission buses (already done in Reading at least – around 40% of the bus fleet is ultra clean). Other actions seem mostly common sense, such as to avoid siting cycle routes on highly polluted roads. Generally speaking, NICE is not impressed with the quality of evidence that the actions it proposes will make a difference. Most of the recommendations are prefaced with the word “consider” (used when the benefits are uncertain). The majority of the studies discussed are described as “poor quality” (though the basis of this assessment is not given in the document at least). NICE therefore makes some recommendations for further research into such topics as the effects of street trees (positive or negative?); clean air zones; the effectiveness of the pollution alert system; and the most effective ways to shift travel modes, and whether this affects personal exposure (e.g. switching your urban commute from car to cycle will reduce overall emissions but probably increase your personal exposure to traffic pollution).

“The message of the report seems to me to be “every little helps – possibly”. The report does reject some ideas, such as street washing, but generally the actions proposed seem likely to make small incremental improvements at best. There is no overall assessment of the likely effects of the proposals on air quality. Given the doubts that NICE seems to have about the quality of the evidence base, and the enormous current interest in improving air quality, some better quantification of the most promising of these suggestions should be useful to policymakers.”

* ‘Air pollution: outdoor air quality and health – NICE guideline, Draft for consultation, December 2016’ will be published by NICE at 00:01 UK time on Thursday 1 December 2016, which is also when the embargo will lift. 

Declared interests

Prof Ian Colbeck: “Member: Institute of Physics, Royal Meteorological Society, The Aerosol Society, International Society of Indoor Air Quality and Climate.

Funding: NERC, EU.

Voluntary appointments: Essex Air Quality Consortium.”

Prof Jonathan Grigg: “Prof Jonathan Grigg receives funding for his research into health impacts of air quality from the Medical Research Council.  Jonathan has a grant from Drayson Industries to evaluate their Clean Space app in asthmatic children.  He is also a member of COMEAP (DH’s Committee on the Medical Effects of Air Pollution).”

Prof Richard Skeffington: “I don’t think I have any significant vested interests. I teach a third year and masters course in air pollution at the University of Reading where I have been since 1999. From 1977-1999 I worked, mostly on air pollution, in the electricity supply industry, and I do consultancy work. Currently I don’t have any air pollution-related research grants.”