Recent advances in the understanding
of the health impacts of air pollution
Frank Kelly
King’s College London
The case for a national network of low emission zones
Coin Street Community Centre, 1st May 2014
Update sources since 2005 WHO guidelines
• 1000’s new health studies, reviews (20062014)
• NPACT study (2013); ESCAPE (2013)
• REVIHAAP (July 2013); HRAPIE (Dec 2013)
• HEI Ultrafines report (2013)
• WHO Black Carbon report (2012)
• IARC Diesel exhaust report (2013)
• WHO Burden of disease report (March 2014)
Recent developments in the evidence of the health
effects of traffic pollutants – PM2.5 and NO2
Increased volume of evidence
Role of fractions
Broader range of evidence
Benefits of improved air quality
As concluded by REVIHAPP
• Since WHO 2005 there is additional support for the effects of
short-term exposure to PM2.5 on both mortality and morbidity
based on several multicity epidemiologic studies.
• Since WHO 2005 there is additional support for the effects of
long-term exposures to PM2.5 on mortality and morbidity based on
several studies of long-term exposure conducted on large cohorts in
Europe and North America.
• An authoritative review of the evidence for cardiovascular effects,
conducted by cardiologists, epidemiologists, toxicologists and other
public health experts, concluded that long-term exposure to PM2.5
are a cause of both cardiovascular mortality and morbidity.
Recent developments in the evidence of the health
effects of traffic pollutants – PM2.5 and NO2
Increased volume of evidence
Role of fractions
Broader range of evidence
Benefits of improved air quality
As concluded by REVIHAPP – PM2.5
• Significantly more insight has been gained into physiological effects
and plausible biological mechanisms linking short- and long-term
PM2.5 exposure with mortality and morbidity as observed in
epidemiological, clinical and toxicological studies;
• Additional studies linking long-term exposure to PM2.5 to several
new health outcomes including atherosclerosis, adverse birth
outcomes and childhood respiratory disease;
• Emerging evidence also suggests possible links between long-term
PM2.5 exposure and neurodevelopment and cognitive function as
well as other chronic disease conditions such as diabetes.
As concluded by REVIHAPP – NO2
• Many new studies document associations between day-to-day
variations in NO2 concentration and variations in mortality, hospital
admissions, and respiratory symptoms.
•
Studies have now been published, showing associations between
long-term exposure to NO2 and mortality and morbidity.
•
Both short- and long-term studies have found these associations
with adverse effects at concentrations at or below the current EU
limit values.
•
The results of these new studies provide support for updating the
2005 global update of the WHO air quality guidelines which could
result in lower guideline values.
Recent developments in the evidence of the health
effects of traffic pollutants – PM2.5 and NO2
Increased volume of evidence
Role of fractions
Broader range of evidence
Benefits of improved air quality
Role of PM fractions
Chemical Composition
Physical properties
Source types
Transition metals
Size
• UF
• Fine
• coarse
Traffic
• Carbonaceous material
• Traffic-generated dust
Black carbon
Particle number
Coal combustion
Organic carbon
Surface area
Industry
• Shipping
• Power generation
• Metal industry
Secondary inorganic
aerosols
Biomass combustion
Desert dust
Source types
• Road traffic
– Carbonaceous material
– Traffic generated dust including road, brake & tyre wear
•
•
•
•
•
•
Coal combustion
Shipping (oil combustion)
Power generation (oil & coal combustion)
Metal industry (nickel)
Biomass combustion (wood combustion, wild fires)
Desert dust episodes
Traffic is the main source of urban pollution
Manchester
Glasgow
Summary of air pollution related health
effects
Health outcome -
Association
epidemiology evidence synthesis
- with traffic air
pollution exposure
Mortality
All-cause & CV
Sufficient
Asthma & Respiratory – children
Asthma onset & prevalence
Sufficient
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
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
Recent developments in the evidence of the health
effects of traffic pollutants – PM2.5 and NO2
Increased volume of evidence
Role of fractions
Broader range of evidence
Benefits of improved air quality
Improvements in PM10 (& PM2.5)
reduces respiratory symptoms
New Cough
New Wheeze
Persistent Cough
Persistent Wheeze
SAPALDIA Study, Schindler et al, 2009
THANK YOU FOR YOUR ATTENTION!
Change in life expectancy, 1980-2000 (yr)
PM2.5 air pollution & life expectancy
in the US
Reduction in PM2.5, 1980-2000 (μg/m3)
Pope et al, 2009
REVIHAAP – Question C2
Is there any new evidence on the health effects of NO2 that impact upon the
current limit values? Are long-term or short-term limit values justified on the
grounds that NO2 affects human health directly, or is it linked to other co-emitted
pollutants for which NO2 is an indicator substance?
10 years of air quality guidelines
Particulate matter (PM)
Nitrogen dioxide (NO2)
Ozone (O3)
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Across the UK poor air quality......
• resulted in the equivalent of 29,000
deaths due to breathing tiny particles
released into the air (in 2008)
• the average loss of life was 11.5
years, (although the actual amount
varies between individuals)
Published December 2010
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