STEP Conference - 4th November 2015

Cleaner Air, Healthier Places

Dr Colin N. RamsayConsultant EpidemiologistEnvironmental Public Health

Health Protection Scotland

V1.1 FINAL

Improving our Messages on Health –

Communicating the Evidence

Telegraph

Air pollution stunting children's lungs, study finds A six-year study finds children living in highly polluted parts of cities have up to 10 per cent less lung capacity than normal, with warnings the damage could be permanent.

Evening TimesAir pollution is killing 3500 Scots every

yearThe official death toll from the toxic fumes that belch from

vehicle exhausts has nearly doubled, meaning that more

than 3,500 people die every year from air pollution in

Scotland.

New figures from the UK government estimate for the first

time the number of deaths blamed on nitrogen dioxide gas,

as well as tiny sooty particles. Environmentalists estimate

that this translates to at least 3,500 deaths a year in

Scotland, compared to a previous estimate of 2,000.

• Natural sources – agriculture, sea spray (salts);

• Manmade:

−combustion for heating and electricity generation;

−hydrocarbon fuelled transport – especially road traffic;

• Etc, etc, etc.

Traffic Related Air Pollution (TRAP)

• TRAP is created via use of motorised transport (cars, taxis, buses, lorries, trains). – exhaust emissions, brake dust, tyre wear.

• Complex mixture – PM; NOx; Ozone, SO2, PAHs, metals etc;

• Major component of ambient air pollution especially in urban areas;

• Not uniformly distributed:

−variations over days / months / years;

− localised “hot-spots” - especially NOx (NO2).

Air Pollution and Health – a complicated story

Assumptions on Air Pollution, TRAP and Health

• Air pollution is bad for people’s health;

• Reducing air pollution should improve Scotland’s health;

• Not all air pollution can be controlled (natural sources, transboundary);

• But people create TRAP – so it should be reducible;

• Reducing TRAP means people will have to change their travel habits;

• We need to encourage / persuade people to change travel habits;

• Improving the messages on air pollution and health should help

change people’s travel habits.

Evidence-based Risk Communication Model

− people don’t know the facts - on air pollution and health;

− people need the facts to improve their awareness and understanding;

− facts need to be evidence-based, scientifically correct;

− once people have the facts, awareness and understanding of the need to change travel habits will improve;

− people will then change from cars to alternatives – public transport / active travel;

− traffic related air pollution will then reduce – people will be healthier.

So what are the facts?

Air Pollution and Health Impacts Project (APHIP)

Project Aim:

Develop evidence-based messages on air pollution and health:

− to support S.Gov efforts to reduce road traffic related air pollution.

Research Questions:

What is the expert consensus on the scientific evidence for:

1. Impact of air pollution on physical health and general well-being?

2. Impact of interventions aimed at changing people’s travel behaviours?

APHIP - Key General Findings

• Air pollution does not directly cause distinctive diseases (cf. lung cancer

from smoking; liver cirrhosis from alcohol);

• Air pollution aggravates existing poor health:

− respiratory illnesses (asthma, COPD);

− cardiovascular disease.

• Impacts vary by: age; gender; location; socio-economic status; pre-existing

health:

− effect of air pollution magnifies other adverse factors;

− rates of death / illness already worse in older, poorer people.

Therefore, air pollution = a health inequalities issue.

APHIP - Key Findings

Air pollution / TRAP is a complex mixture (PM; NOx; O3; etc):

• Health studies usually look for effects on single pollutants (e.g. PM);

• But difficult to identify impact associated with individual pollutants;

• Uncertainty - not clear what is most important component or how they work.

APHIP - Key Findings - Particulates

Particulates:• Also a complex mixture: carbon; metals; nitrates; sulphates etc.;

• What matters:− carbon / metals / salts;

− particle mass (PM10, PM2.5, ultrafine), particle number;

− within mass groups (PM2.5) – which components matter most:

− primary combustion particles (hydrocarbon fuels) / black

carbon / nitrates / sulphates;

− evidence not good enough to quantify separate effects;

− scientific uncertainty.

APHIP - Key Findings – Particulates

• Impacts being identified at progressively lower PM concentrations;

• No clear threshold level – no lower limit.

Short-term Exposure – acute impacts of air pollution peaks• Increased risk of death from lung disease (asthma, COPD) and heart

disease (heart attacks);

• Increased risk of illness and hospital admission for lung and heart

diseases;

• Increased days of work and restricted activity days;

• Increased use of routine medication (e.g. asthma inhalers).

APHIP - Key Findings – Particulates

Long-term Exposure – Ambient Air Pollution

Main impact• Higher adult death rates – all causes; respiratory; cardiovascular (CV);

lung cancer (modest increases in risk of death).

Additional impacts• Evidence for other effects less certain:

− increased infant mortality, poorer birth outcomes (low birth weight,

premature birth);

− development of new chronic obstructive pulmonary disease (COPD);

− development of new CV disease: marker conditions e.g.: diabetes;

neurological impairment (dementia).

APHIP - Key Findings - Particulates

PM2.5 In Scotland

Reduced average adult life expectancy of 3 to 4 months (based on mean

PM2.5 of 5µg/m3); COMEAP (2010).

• If manmade air pollution was only cause of death – equivalent to 1560

deaths (in 2008) or 2.8% of all deaths;

• PHE (2014) estimate of 2094 “attributable deaths”:

− compared to road fatalities of 281 (actual) deaths (2007);

− but complex modelled statistical estimate, inbuilt scientific uncertainty.

APHIP - Key Findings – NOx / NO2

• NO2:

− precursor of nitrate PM and ozone;

− focus of current concern (increased contribution from diesel engine

vehicles – cars).

• Good evidence of both short-term (acute) and long-term (chronic) health

impacts:

− increase mortality (approximately same scale as for particulate

matter);

− increased hospital admissions.

• But NO2 levels strongly correlate with PM / ozone;

• So - how much of impact is NO2 itself – scientific uncertainty;

• COMEAP – new report quantifying impacts of NO2 on mortality due end

2015.

Newer Evidence (Post-APHIP)

London Based Research Programme (TRAFFIC, AWESOME etc.)

• Traffic sourced air pollution – primary pollutants and impact on mortality:− short and long-term impacts in mortality.

• Short-term exposures (Atkinson et al 2015):− levels of PM2.5, NO2,elemental / black carbon (EC / BC) (diesel exhaust);

− small associations; negative for CV mortality; positive for respiratory

deaths;

− no evidence of association between NOx (or NO2) and mortality (all or

specific cause);

− suggests specific association between diesel exhaust (EC / BC) and

respiratory mortality (small effect).

• Long-term exposures (Halonen et al 2015):−weak evidence of positive associations with mortality;

−no clear dose / response relationship (e.g. lowest effect with highest

exposure).

APHIP – Summary of Consensus Findings –

Impacts on Physical Health and Wellbeing

• Scientific uncertainty on many aspects of links between air pollution /

TRAP and health impacts;

• People do not die only from exposure to air pollution but air pollution

adds to the risk of death;

• Air pollution shortens average life expectancy – but mainly hastens fatal

decline in those already vulnerable – “premature” death;

• For some people (minority) reducing air pollution / TRAP could

markedly improve health, quality of life, life expectancy;

• For most people - reducing air pollution / TRAP = marginal impact on

health and life expectancy.

APHIP - Key Findings - Air Pollution and Wellbeing

Wellbeing:• Presence of positive emotions and moods (contentment; happiness);

• Absence of negative emotions (depression, anxiety);

• Life-satisfaction, fulfilment and positive functioning (CDC).

Evidence linking air pollution and wellbeing:Sparse and relatively weak:

• Some association between particulate matter and anxiety but no dose-

response relationship;

• Air pollution – predictor of differences in subjective wellbeing between

countries and between time periods;

• Traffic congestion associated with poorer quality of life (?noise related);

• Better evidence of positive associations between greenspace: walking,

cycling and better mental health;

• No good evidence specifically on effects of TRAP on wellbeing.

Factors affecting people’s choice of transport:• Personal factors: age; gender; family status; education;

• External factors: urban / rural location; infrastructure; geography; climate

(rainfall, temp); air quality;

• Transport option factors: cost; convenience; time; effort;

• Habit ;

• Health impact of air pollution – very little evidence to suggest this is a

significant factor affecting choice.

APHIP - Key Findings – Behavioural Change

Little published research on air pollution, transport use and behaviour

change.

“Principles for communication on Air Pollution (particulates)”

(DEFRA Project)

• Focus on negative impacts provokes negative reactions:− disgust, revulsion, over-reaction, resignation, disengagement;

• Information on what particles do to you has more impact than health

statistics (e.g. reduced life expectancy);• Scientific uncertainty (controversy) provides excuse for avoiding issue.

• Recommended communication should focus on:

−certainties not uncertainties;

−pollution as a specific / local issue – not a general (national / global)

issue;

−practical improvements to reduce local air pollution;

• Only raise awareness / concern if you can offer practical options to help

people change behaviour.

Communicating on Air Pollution

APHIP - Key Findings - Behaviour Change

• Congestion charging associated with reducing TRAP but successful

introduction depends on public engagement and support;

• Personal travel plans and feedback programmes can work:

− information on impacts of travel choices on air pollution, etc;

−encouragement to complete travel diary;

−prompt people to think about alternatives;

−suggestions on alternative travel options and how these could be

adopted realistically;

− individualised support for travel behaviour change;

−NB: resource intensive.

Conclusion

• Providing health information to individuals is only one element.

Current Messages

Air pollution and health

“Air pollution kills ≈2000 people in Scotland each year, many more than road accidents”:

− Dramatic – but technically not true – Far more complicated story.

“Air pollution will (on average) shorten your life expectancy by 3 to 4 months”:

− Technically correct but complicated.

“Air pollution – you are creating it”

− you need to change your travel habits.

“Smoking Kills”:

− clear, shocking, unequivocal, memorable;

− strong scientific evidence;

− strong cause / effect link;

− high relative risks;

− but effective among smokers?versus other initiatives / targeted personal initiatives(e.g. smoking cessation clinics);

− legislation – public places ban / advertising ban;

− culture change / social pressure –smoking is now seen as anti-social.

Improving our Messages on Health

What can we learn from other

Public Health examples?

Conclusions on Communicating the Evidence

“Framing” air pollution and health

• “There is no guarantee that more information will lead to greater

acceptance, or that the availability of facts will lead to a more ‘rational’

and calculative form of choice making” (Williams L. et al, 2015).

• Science based controversies – typically about expert and governing

institutions who...

“Tacitly and furtively impose prescriptive models of the human and the

social upon lay people, and these are implicitly found wanting in human

terms (Wynne B. 1996).

Conclusions on Behaviour Change

Behaviour change is highly complex

(e.g. ISM model):− Individual component – one

aspect – highly personalised;

− Societal :government policy,

(pricing strategies; taxation etc),

also cultural norms - acceptability;

− Material (e.g. Infrastructure,

availability of alternatives,

convenience).

Conclusions on Communicating the Evidence

• Public are not receptive to negative health messages (death / disease);

• Stress positive benefits of alternatives to car use:

• Link air pollution more with existing public health messages on increasing

exercise / activity, reducing obesity etc:

− Active travel messages embedded in existing programmes

e.g. ‘Paths for All’, ‘Cleaner Greener Scotland’, ‘Beat the Street’;

• Encourage more local initiatives: CAFS requirement on NHS boards / LA

− raise profile of air pollution via local Joint Health Protection Plans.

• Empower individuals and “communities” – don’t just expect people to

change their behaviour because we say so – they have to want to change.

Beat the Streets

Local initiatives – active travel

• Focus on benefits of active travel:− focus on communities / workplaces;

− Less overt focus on air pollution.

Beat the street launches in Annan and

DalbeattieSep 2, 2015

From the 1st of September, residents of

Annan/Dalbeattie will be encouraged to take to

the street and help each community reach the

goal of ‘walking around the world’. Locals can

walk, run, cycle, scoot, skate or skip between

locations during the 6 week campaign in order to

win prizes for themselves and their communities.

APHIP Conclusions on Improving Health Messages

• Aim messages at multiple targets: public / politicians / professionals;

• Providing health messages to the public may improve awareness but will

not be enough to change people’s travel habits;

• Key messages from APHIP on Scotland’s Environment Web (SE Web);

• Multiple messages multiple targets: − Public: health facts, positive benefits of changing travel habits to more

active travel;

− Employers / industry: encourage and facilitate change in travel habits

of staff and customers;

− Politicians: role of local and national government to:

“shape the places we all live and work in to make healthier travel

habits the natural choice”.

Improving our Messages on Health

Air Pollution and Health

A possible mass media message?

“Four wheels bad;

two legs better –

traffic pollution is bad

for everyone’s health”

Acknowledgements

APHIP Funding: SG Environment Directorate / SEPA/ SE Web

Project (EU)

Steering Group: Ann Conrad (SEPA); John Redshaw (SEPA);

Sheila Beck (NHS Health Scotland)

IOM Research Team: Hilary Cowie, Joanne Crawford; Alice Davis;

Susanne Steime; Stefan Reiss; Kev Dixon;

George Morris; Fintan Hurley

SE Web: Paula Brown (SEPA)

Sources of Further Information

Further information on APHIP findings including IOM Report (Air Quality,

Health, Wellbeing and Behaviour) on SE Web:http://www.environment.scotland.gov.uk/media/126007/iom-seweb-aq-health-behaviour-

review.pdf

DEFRA / Parliament Hill Research:http://randd.defra.gov.uk/Document.aspx?Document=12465_AQ1010FinalProjectReport.pdf

DEFRA website:

https://www.gov.uk/government/organisations/department-for-environment-

food-rural-affairs

ISM Model:

http://www.gov.scot/Publications/2013/06/8606/1

Sources of Further Information

Breathe London:

http://www.breathelondon.org/

Environmental Protection Scotland; Breathe Scotland:

http://www.breathescotland.org.uk/

Paths for All:

http://www.pathsforall.org.uk/pfa-home

Halonen, J.I. et al., Is Long-term exposure to traffic pollution associated with

mortality? A small-area study in London. Environmental Pollution (2015):

http://www.sciencedirect.com/science/article/pii/S0269749115003292

Atkinson R.W et al. Short-term exposure to traffic-related air pollution and

daily mortality in London. Journal of exposure science and environmental

epidemiology (2015), 1-8: http://www.ncbi.nlm.nih.gov/pubmed/10450240

Copyright: PHE Blog; 3 Nov 2015; https://publichealthmatters.blog.gov.uk/2015/11/03/understanding-the-impact-of-particulate-air-pollution/

Comparing risk factors