TRL Academy Air Quality Symposium Dr Iarla Kilbane-Dawe, Office of the Chief Scientific Adviser, Dft. Copyright 2016 TRL Ltd

Transcription

1 TRL Academy Air Quality Symposium Dr Iarla Kilbane-Dawe, Office of the Chief Scientific Adviser, Dft 1

2 Air quality sources & the role of different parts of Gov t Historic improvements Scale of the challenge Role of transport Key opportunities to do more and better 2

3 Sources of air pollution Air pollution comes from many different sources, man-made and natural Air pollution changes as it blows on the wind. Pollution gets diluted as it blows downwind the closer you are to the air pollution source, the higher the pollution you experience. NO 2 and other emissions from industry, power stations, agriculture and nature all turn into PM after a few hours. Farming adds to PM - as fertiliser breaks down it forms PM. Dust blown off soil, roads and distant deserts adds to PM Aircraft at take-off add to NO 2 (cruise aircraft emissions are blown away) Industry adds to PM and NO 2, and can release vapours that turn into PM. Bonfires and fireworks add to PM Traffic and rail exhaust adds to PM and NO 2. Brake, tyre and road/rail wear add to PM. Fuel vapour adds to PM. Building and home heating Gas heating makes NO 2, wood (including from CHP) and coal heating make PM. Vapour from fuels also add to PM. Shipping exhaust adds to PM and NO 2 The sea releases salt and sulphur adding to PM Adapted from 3

4 As a result, many different authorities must collaborate to improve anthropogenic emissions Different Central Gov t Dep ts & agencies have different responsibilities Defra national & international compliance (Env Act, CLRTAP, NECD, CAFÉ, IPPC, LAQM, NAQP); agri & energy emissions; primary evidence base & models. DfT vehicle emissions (Euro) standards, EVs/ULEVs, rail, sea and air vehicle emissions, traffic management, AQ compliance of new transport infrastructure, transport appraisal framework (webtag), project funds. DH medical evidence; PHOF, role of DsPH. Role of NHS in emissions. BEIS energy generation and mix. DCLG supports LAQM delivery and local action. National, regional and local governments have lead roles. Scottish, Welsh, Northern Ireland and London air quality strategies. Delivering LAQM, coordinating between Public & Env Health, Transport, Planning etc. International institutions e.g. EU, UNECE, USEPA, CARB, WHO. Scientific & medical authorities e.g. WHO, learned societies, HEI. 4

5 This has been very successful Reduction in black smoke in Lambeth Revision and tightening of the 1956 Clean Air Act (1968) CLRTAP comes into force - US, UK, USSR & other nations (1983) Euro emissions standards (1992) Envir t Act (1995) PM 10 concentration, ug/m Reduction in PM 10 at Marylebone roadside Other London locations also shown WHO (2013) recommended limit for PM 10 Euro 3 begins for cars Euro 4 begins for cars Euro 5 begins for cars (2009) Marylebone Rd Horseferry Road Bloomsbury Brixton Road Euro 6 begins etc Year Air pollution is substantially better than even 20 years ago. Measurements of particulates have reduced by about 97% since the 1960s, as in the Black Smoke record shown above. Ambient levels of CO, Pb, SO 2, HNO 3, H 2 SO 4,C 6 H 6, 1-3- Butadiene are at levels considered to be safe. The benefits have never been estimates, but it seems likely this has led to substantial improvements in lifespan and quality of life in the UK, and better crop production. At the same time, new evidence has emerged that even the low levels of PM pollution today lead to substantial public health effects. And new evidence on NO 2 is emerging. Continuing areas of attention include reducing PM and NO 2 levels near busy roads, NO 2 and NO x from both vehicles, heating and power generation, emissions from trains, shipping, natural gas and fuel vapour, ammonia from agriculture, and dust generated by brake, tyre and road surface wear, ploughing and construction. 5

6 But developing medical evidence challenges us PM health effects were first identified in statistical analyses of death rates in the mid- 1990s. These health effects are now understood to occur even at very low concentrations. Statistical evidence on NO 2 health effects emerged in Scientists are using lab studies to work how it could be causing the effects seen in statistics, or if these are due instead to something closely related to NO 2. PM can cause strokes. Ultrafine PM has been found in samples of brain and central nervous system tissue. Heart and blood vessel diseases like strokes and hardening of the arteries are one of the main effects of air pollution. These can be caused by a few years exposure to even low levels of PM 2.5 (over about 10µg/m 3 ). Exposure for a few hours to high levels of PM 2.5 (over about 50 µg/m 3 ) can bring on existing illness or strokes and heart attacks in ill people. Figure adapted from the EEA publication Health Impacts of Air Pollution A few hours of PM 2.5 over ~35µg/m 3 or NO 2 over ~200µg/m 3 irritates the eyes, nose and throat, causing breathing problems or asthma attacks in sensitive people. Years of exposure to even low levels of PM 2.5 (10-25 µg/m 3 ) can lead to lung cancer and incurable lung disease, and reduced lung function. Ultrafine PM can get into the blood then throughout the body. Ultrafine particles have been found in bodily organs. PM has been found in the reproductive organs and in unborn children. 6

7 Even at µg concentrations, air pollution is very harmful A World Health Organisation science review found there is no safe level of long term exposure to PM, arguing for a reduction in annual average limits for PM 2.5 from 25µg/m 3 to 10. The best estimate of the effects of PM on health in the UK is 55, ,000 years of life lost per year. This uncertainty takes account of factors like individual dose, pre-existing illness etc. It could turn out that some of this uncertainty could be explained by discoveries relating to the effects of NO 2. The widely quoted figure of 29,000 deaths per year due to PM is used to explain in layman s terms, by summing up the many small effects on lots of people. Estimates of the effects of air pollution rank it in the top 10 or 12 causes of death in the UK, and perhaps even the top 5 or 6. Emerging evidence on the direct health effects of NO 2 - first estimates put this at 9,500-38,000 on top of PM 2.5 effects, but this remains uncertain. 7

8 How much does transport contribute to PM? Annual mean PM2.5 transect across London for 2009 from PCM model Estimated average PM 2.5 while crossing Greater London, West to East Local PM emissions Local traffic PM Local non-traffic PM PM component (ugm -3) Reading WHO recommended PM 2.5 limit for health - 10 µg/m 3 Level where PM 2.5 health impacts are though to begin 5-6 µg/m 3 Central London Easting (m) Southend- On-Sea Urban dust traffic area sources non-traffic Rural area sources dust point sources urban dust Regional PM sources rural dust Upwind PM emitted by transport, power & industry regional primary Distant upwind fuel vapours that has turned into PM secondary organic secondary Distant inorganic PM sources residual sea salt PM from nearby power, large boilers & factories Distant upwind NOx (from transport & power), sulphur (from the sea, ships & power stations), fuel vapour and ammonia (from farms) that s turned into PM. Other sources Sea salt EU Limits and Target Values (annual mean) PM gm -3 PM gm -3 Credit: Defra & Ricardo 8

9 From J. Yin et al, doi: /acp How much does transport contribute to PM? Definite traffic pollution Other natural sources (1) Cooking Natural gas that s turned into PM Upwind farms, power & some traffic Upwind farms, power, some shipping Other natural sources (2) Sea Salt Coal burning Dust & soil Wood smoke Dust from dead plants Sources of PM measured in N. Kensington over 4 weeks in 2012 (Measurement location was away from any busy roads) Sources of PM measured in Oxfordshire over 4 weeks in 2012 (Measurement location was far away from any busy roads) 9

10 In cities, the prevalence of junctions, hills, congestion and other features means NO 2 levels look like this Nitrogen Dioxide (NO 2 ) Concentration, µg/m NO 2 measured walking from South to North London on a single day in 2010 Annual average legal limit is 40 µg/m 3 Health effects are thought to begin at or below 40 µg/m 3 over years of exposure. Note the peaks that occur at junctions, busy roads and in streets surrounded by tall buildings that trap pollution Walking south to north across London Environmental Research Group Kings College London 10

11 How much does transport contribute to NO 2? 11

12 How does transport contribute to NO 2? Diesel engines often use systems to reduce PM that increase the NO 2 they emit. Euro 6 vehicles have extra systems to help control the NO 2 as well. At certain VSPs all but the best emissions control systems are overwhelmed, briefly increasing emissions x This can happen up hills, in congestion, over road humps or if driving is aggressive. The peaks can add up to a lot of pollution and the total effect is not well understood. In addition, there are examples of gaming of the old regulations. NOx emissions rate Engine speed Vehicle speed (Merkisz et al., 2010) This map and NO x plot shows how much vehicle emissions change from moment to moment as a petrol car drives around a test route. Peaks can be due to acceleration or hills, or the vehicle systems. 12

13 How does transport contribute to NO 2? Pre Euro 6 RDE NO x engine map. LUBW (State Agency for the Environment, Measurements and Nature Conservation Baden-Württemberg) Area of the pre RDE test cycle 13

14 Euro 6 Real Driving Emissions (RDE) testing is expected to have a really substantial impact on diesel emissions UK has being arguing for RDE testing since An RDE, real world test using a portable emissions measuring system (PEMs) is required in Euro type approval from September Aim is to ensure regulatory emissions limits are met in normal driving. It s the first of it s kind. Since there is no specific RDE test cycle, it minimises the possibility to use a defeat device and can help reduce peaks due to overloading of the emissions control system at certain VSPs. The RDE test is up to 2 hours long, covering three sections: - 34% urban (u=0-60 kph, ū=15-30 kph) 16 km - 33% rural (u=60-90 kph) 16 km - 33% motorway (u= mph) 16 km 14

15 An example of the kind of information that we need to consider in emissions modelling Anabel, Cairns, Chatterton & Wilson, Motoring and vehicle Ownership Trends project, The Floow 15

16 What are the key opportunities to do more and better? Where are the uncertainties? Improve understanding of emissions of the existing fleet and how they are affected by technology, terrain, congestion, temperature, and of emissions of other sources e.g. agri ; Coupling this into emissions, inventory, air quality and analytic models; Likely to require modern computational solutions e.g. big data ; Joined up work between vehicle engineers, emissions & AQ scientists is essential; Are there GEVs, if so why are they GEVs & how can we detect and manage them? Direct effects of NO 2 on health, emerging evidence on PM and other air pollutants, composition related effects of PM; Effective and cost effective methods of reducing emissions and concentrations, on, in or off vehicle, while RDE and EVs are taken up over coming years, and from other sources: shipping, agriculture etc. Other issues, albeit not uncertainties: Need for the science, consulting and engineering communities to respond to this challenge and ensure that the best available evidence is supplied to all authorities. What were the benefits of our past successes? 16

17 Symposium Questions? Air Quality: The urgent need to mitigate transport impacts on health Dr Iarla Kilbane-Dawe Head of Partnerships & Engagement, DfT Tel: