Dr Ian Mudway studies the health effects of air pollution. His research focuses on additives and chemicals found in particulate matter from sources like nitrogen dioxides, ozone, diesel exhaust, and volatile organic compounds. His work shows associations between exposure to traffic-related air pollution and increased mortality, exacerbation of asthma, and reduced lung growth in children. While past exposures correlated with health impacts, more research is needed on contemporary pollution levels. Controlling pollution, especially near vulnerable groups, and transitioning to cleaner fuels could help reduce disease burden and extend lifespans.

1. Dr Ian Mudway
Health Effects of Air
Pollution
ian.mudway@kcl.ac.uk

3. Additives
Nitrogen dioxides (incl. NO2),
ozone, particulate matter,
volatile organic carbon
compounds.
PM associated
chemicals
Nitrogen dioxides (incl. NO2),
ozone, particulate matter
(PNC, PM2.5, PM10, coarse PM),
organic carbon, elemental
carbon, volatile organic
carbon compounds, quinones.
PAHs, metals (Fe, Cu, Cr, V, Ni,
Sb, As, Cd, Al, etc), stable
radicals, SOA, POA, sulphate,
nitrate, NaCl.

4. Diesel
What’s the consequence of this?

5. But this is what happened

6. Burden of disease from 20 leading
causes in 2010
Lim et al. LANCET (2012)
Ambient air pollution (PM2.5):
Globally:
- 3.1 million deaths
- ~ 3.0% of all DALYs
In Western, Central and Eastern Europe:
- 430,000 premature deaths;
- over 7 million years of healthy life lost Lim et al. LANCET (2012)

7. • 1000’s new health studies,
reviews (2006-2015)
• NPACT study (2013); ESCAPE
(2013)
• REVIHAAP (July 2013);
HRAPIE (Dec 2013)
• HEI Ultrafines report (2013)
• WHO Black Carbon report
(2012)
• IARC Diesel exhaust reports
(2013/2014)
• WHO Burden of disease report
(March 2014)
What is already known

8. Conclusions of the HEI Traffic Report 2010
Health outcome Association with traffic air
pollution exposure
Mortality
All-cause & CV Sufficient
Asthma & Respiratory – children
Asthma onset & prevalence
Asthma is more common in children living in the street buffers with
the highest concentration of traffic-related pollutants
Exacerbation of asthma symptoms
Children living in hot spots of traffic-related pollution experience
more symptoms and exacerbations
Sufficient
Sufficient
Asthma & Respiratory – Adults
Adult onset of asthma (one study)
Exacerbation of asthma symptoms (few studies)
Hospitalisation rates
Insufficient
Suggestive but not sufficient
Insufficient
Lung function
Living in proximity to high concentration of traffic air pollution
may be associated with reduced lung function
Suggestive but not sufficient

9. Meta-analysis of the association between long-
term exposure to PM2.5 and all-cause mortality
Hoek et al, EnvHealth 2013
These are all, by and large, associations
derived from old cohorts exposed to
historic levels of air pollution.
What do they tell us about
contemporary exposures?

10. Black Carbon – a better health indictor?
Toxic component or source indicator?
Estimated county- and season-
specific relative risks (RR) of
cardiovascular and respiratory
hospitalization associated with
PM2.5 components in 106 U.S.
counties for the years 1999
through 2005
Janssen et al, Environ Health Perspect, 2011
Systematic review and meta-analysis of
health effects of BC compared with PM
mass based on data from time-series
studies and cohort studies that measured
both exposures

11. Controlled Diesel Exposures
Exposure to DE: PM10 300µg/m3 and filtered air for 1 hour & 100µg/m3 and filtered air for 2
hours

12. Diesel induces inflammation in vivo
Neutrophils
after air
Neutrophils
after DE
• Inflammation
• Impaired lung function
• Injury/remodelling
• Impaired microbial
defences
• Carcinogenic
constituents
• Blood viscosity
• Promotes
atherosclerosis
• Impaired vascular
function
• Ischaemia
• Arrhythmias

13. How does air pollution impact o
children’s development?

14. NO2 in Tower Hamlets & Hackney

15. Internal dose of black carbon

16. 16
Impaired lung growth
Gauderman et al, 2004 (NEJM); southern California
- 1,759 10-yr old children, 12 communities, 8-yr follow up
- Lung function growth significantly reduced in areas with
higher levels of traffic-related pollutants
- NO2, PM2.5, elemental carbon (EC) associated with reduction in growth
of FEV1 of between 79.7 and 101.4 mL
- Clinically low FEV1 at age 18 positively correlated with level of
exposure to NO2, PM10, PM2.5, EC

17. Gauderman et al, NEJM, 351: 1057-67, 2004
- 1.6% at lowest level of PM2.5 exposure
- 7.9% at highest level of PM2.5 exposure (4.9x higher)
Clinically low FEV1 at age 18 yrs

18. 18
Impaired lung growth
Gauderman et al, 2004 (NEJM); southern California
- 1,759 10-yr old children, 12 communities, 8-yr follow up
- Lung function growth significantly reduced in areas with
higher levels of traffic-related pollutants
- NO2, PM2.5, elemental carbon (EC) associated with reduction in growth
of FEV1 of between 79.7 and 101.4 mL
- Clinically low FEV1 at age 18 positively correlated with level of
exposure to NO2, PM10, PM2.5, EC
Gauderman et al, 2007 (Lancet); southern California
-Same study, local vs. regional pollutant levels
-Living <500m from freeway associated with reduction in FEV1 growth
of 81mL (vs. living >1500m away)
-Significantly lower attained FEV1 by 18 yrs

19. Concerning news on the Horizon

20. 20
Causes for Optimism

21. PM2.5 air pollution & life
expectancy in the US
Pope et al, 2009
Reduction in PM2.5, 1980-2000 (μg/m3)
Changeinlifeexpectancy,1980-2000(yr)

22. Improvements in PM10 (& PM2.5)
reduces respiratory symptoms
SAPALDIA Study, Schindler et al, 2009
New Cough Persistent Cough
New Wheeze
Persistent Wheeze

24. John Evelyn 1620 –1706
Cleaner Fuels
Separate the vulnerable
population from pollution
sources
Economic benefits
Green infrastructure
Moral imperative

25. Acknowledgements
Centre for Primary Care and
Public Health, QMUL:
Chris Griffiths, Jonathan Grigg, Robert
Walton, Isobel Dundas, Stephen
Bremner, Nadine Marlin, Louise Cross,
Neeru Garg, Alex Nanzer, Yasmeen
Hanifa, Harpal Kalsi, Tom Round, Peter
Bridge, Ratna Sohanpal, Adam Briggs,
Grace Tuaf Toro, Niki Jakeways, Dev
Gadhvi, Seif Shaheen, Rossa Brugha,
Grainne Colligan, Chinedu Nwokoro,
Anna Schwappach, David McLaughlin,
Neetha Purushotham, Hannah
Smithers.
Environmental Research
Group, KCL:
Frank Kelly, Helen Wood, Jeenath
Jamaludin, Andrew Grieve, Esme
Purdie, Layla Aitlhadj, Eleanor Smith,
Erik Van Nunen, Ben Barratt, Sean
Beevers.
Umea, Sweden:
Anders Blomerg, Thomas Sandstrom,
Annelie Behndig, Sundeep Salvi
Imperial:
Paul Elliot, Mireille Toledano, Liza
Selley, Toby Athersuch