Early Careers Group Meetup, London, June 2018

1. History IAQM
Bernard Fisher chairman 2005 to 2012
beafisher@cantab.net
University of Hertfordshire
25 Years of Air Quality Management - Intended
and Unintended Consequences
• History
• Local air quality management 1996-2000
• Action plans 2018

2. History IAQM

3. A complete
understanding of the
causes of current levels
of air pollution
throughout a region is a
complex problem
beyond the resources
of the largest and most
well-equipped local
authority. Nevertheless
it is possible to obtain
useful conclusions
using simple principles.
Local authorities should
rely in the first instance
on existing national and
local monitoring data,
and simple modelling
techniques.
History IAQM

4. 0 20 40 60 80 100
0
20
40
60
1996
2000
2005
2010
2015
2020
2025
Limit value
Distance fromroad (m)
Concenrations(ppb)
NO2 concentrations near Marylebone Road using my model GRAM
using 2000 emission factors
Local Air Quality Management

5. Table 3 Results of Some Comparisons of GRAM Model
Predictions with Roadside Measurements of NO2 (ppb) in 1995
Local Air Quality Management
Site Location
1995 measurements
NO2 annual ppb
Measured Model
Oxford St London
street canyon
42
Bridge Place London 34 32
Cromwell Road London 47 46
Bloomsbury London 35 34
Marylebone
London
40 44

6. Local Air Quality Management

7. Without Action Plan 2018
We focus on one road (Marylebone Road)
The baseline NOx emissions over the above period used in PCM are as follows:
NOx emissions 2018 2020 2025 2030
Marylebone Road
tonnes/km
18.1 13.8 8.6 5.6
All road links
tonnes
179,000 155,000 103,000 75,000
National Plans 2017 introduce Clean Air Zones as a further
local measure to speed up compliance

8. The July 2017 National Plan includes a
commitment to end the sale of diesel and petrol-
only vehicles by 2040
Trend in emissions of NOx along the Marylebone Road
(tonnes per year per kilometre). Baseline and baseline + CAZ
20 22 24 26 28 30
0
5
10
15
Baseline trend in NOx emission
Trend in NOx emission with ULEZ
Action Plan 2018

9. The baseline PCM estimate of NO2 concentration with CAZs for the Marylebone
Road (coordinates 528.000, 182.004), are:
Roadside
Marylebone Road
Years
2015 2020 2025 2030
NO2 concentration
ppb
47 30 19 17
(2025 is the only change from the baseline estimate)
Compliance in 2023 instead of 2026 with CAZ
Action Plan 2018

10. Near road
0 20 40 60 80 100
0
10
20
30
40
Oxidant upper bound
Photostationary state
Far from road
NO2 = (O3back+f-NO2 x NOx) x function(NOx)
Primary NO2 emission from vehicles
NO2 v NOx equilibrium relationship for different
amounts of sunlight
ActionPlan 2018

11. 0 20 40 60 80 100
0
10
20
30
40
2018
2020
2030
Limit value
Concentration of NO2 (ppb) in my dispersion calculation
(GRAM) near Marylebone Road
Action Plan 2018

12. The effect of the CAZ on NO2 in Marylebone Road
is to reduce lives lost by 5% over 10 years
The effect of the CAZ on NO3 in Marylebone Road
is to reduce lives lost by 13% over 10 years
The effect of the CAZ in Marylebone Road is to
reduce lives lost by 11% over 20 years
Health benefit from my estimate (GRAM) for all distances and all road
transport (NOx and PM2.5 ) emissions for Marylebone Road
Action Plan 2018

13. Conclusions
Planning and environmental assessment has developed greater awareness of air
quality - qualitative benefit of air quality management. Use of air pollution
measurements and models has become widespread. There has to be reliance on
models to consider future scenarios.
Unintended policy failure. Lack of national leadership. Effective action plans for NO2
not brought forward, recognition of future uncertainty in emissions. PM2.5 needs
transboundary considerations NECD.
Unintended process failure. Too complex. Fruitless paper exercise. Flaws in
guidance - non-linearity in NO2, comprehensive models v PCM.
Conclusions

14. Uncertainty in PCM baseline
Upper and lower bounds on non-compliant reporting zones
Without Action Plan 2018

15. Reduction is a small fraction about 1.5% of total road transport emissions
over 10 years
Changes in national NO2 emissions resulting from CAZs (kt/year)
over 10 years
Action Plan 2018

16. Figure 4. A nomogram for estimating the depth of the boundary layer in day time in
the absence of marked advective effects or basic changes in weather conditions.
The marked example shows how the diagram is to be used
Nomogram

17. Emission Factors
Average emission by vehicle type (g/km) and number of vehicles in 2015

18. Thoughts on the new Government strategy
Diesel vehicles Euro standards
Emission Factors

19. Types of Clean Air Zones by vehicle type
CAZ is a local measure to deliver compliance in the shortest time possible
UK National Plan

20. The UK National Plan considers additional measures such as
(1) taxation to encourage switch from diesel to hybrid or less polluting
vehicles
(2) scrappage
(3) promoting hybrid vehicles, which are heavier and may produce more
non-exhaust emissions
(4) zero emission taxis. In London all new taxis will be zero emission
from now 2018 onwards.
(5) encouraging cycling and walking
(6) improved driving techniques by education and technology.
UK National Plan

21. Streamlined Pollution Climate Mapping model SL-PCM a spreadsheet
to assess NO2 near roads within Clean Air Zones within which older vehicles
are restricted.
Users choose CAZ and model runs quickly for 9336 road receptors
The SL-PCM does not take account of changes
from measures on cold starts, minor roads,
background concentrations and the fraction of
primary NO2 emitted (f-NO2)
Action Plan

22. 31 22 17 ppb baseline NO2 concentrations
for Marylebone Road using PCM model in
2020 2025 and 2030 with compliance in
2026.
31 19 17 ppb baseline + CAZ.
Compliance in 2023 with CAZ/ULEZ.
Action plan

23. For Marylebone Road the PM2.5 concentrations
from my dispersion calculations are 21 15 15 µg/m3
in 2010 2020 and 2030 with 2.3 µg/m3
non-exhaust
alone.
Note compliance with 20 µg/m3
target by 2020.
There would be a question over the WHO
recommendation of 10 µg/m3
.
Action Plan

24. Action plan
We need to know the overall effect of bringing forward the reduction in NOx
emissions in Marylebone Road not just the local effect at the roadside to
comply with the Limit Value.
Some NOx is eventually converted to NO3 particulate with a health effect
different to NO2.
We consider a diagnostic Health Impact of Road in terms of lives lost which
depends on the population density ρ(x) at a distance x from the road and the
concentration C(x) at the same distance
0
∞
xC x( ) ρ x( )
⌠

⌡
d

25. Benefit is worthwhile but what is the overall benefit?
February 2018 UK Government plan declared unlawful
Government lost third case 23 February 2018
Focus is too local and there is too much uncertainty
My approach would be to see if Euro 6 with the new test procedures
actually works by following trends in Marylebone Road and elsewhere.
+ primary NO2 from vehicles
+ control of non-exhaust particulate matter
+ on road testing
+ in service emission programme
Action plan
To the question DO I LIKE THE UK NATIONAL PLAN my answer is NO