INSTITUTE OF OCCUPATIONAL MEDICINE . Edinburgh . UK www.iom-world.org

A cyclist’s perspective

John Cherrie and Karen GaleaJohn.Cherrie@iom-world.org

With help from Melanie Gorman Ng and Araceli Sanchez Jimenez

SEPA LAQM 26 March 2013

Pollutants are not uniformly distributed…• We see variation in

space and time at fixed point monitoring stations

• People move through space and so each person experiences different exposures

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www.scottishairquality.co.uk

Pollutants concentrations vary…

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Cyclists have higher exposures…• One might expect that cyclists

are likely to have higher exposures than non-cyclists

• But is that the case?

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Data from China…

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Wu D-L. Influences of Commuting Mode, Air Conditioning Mode and Meteorological Parameters on Fine Particle (PM2.5) Exposure Levels in Traffic Microenvironments. Aerosol Air Qual Res Published Online First: 2013. doi:10.4209/aaqr.2012.08.0212

In cab is now less polluted?

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Children may have higher exposure… • Child cyclists may have higher exposure

than adults• Children are smaller and height above the

emission sources, i.e. the tailpipe may be important

• Buzzard et al showed that exposure of adults about half that of a child

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Buzzard NA, Clark NN, Guffey SE. Investigation into pedestrian exposure to near-vehicle exhaust emissions. Environmental Health 2009;8:13.

Sensors…

• We have had a range of direct reading monitors for some time

• The difference now is that relatively sensitive low cost devices are becoming available with data-logging capabilities

• Coupled with information about position, activity, environment etc. they can make a clearer picture of exposures

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Demonstration from a cycling journey

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MapMyWalk.com

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www.MapMyWalk.com

Concentration data

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Throughout the cycle journey

Dashboard…

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Watch at…www.youtube.com/watch?v=PafT2SN6GmM

Some key observations

• Concentration response lagged in relation to sources

• Response also smoothed to some extent• The move from the quiet campus

to the roads associated with a rise in concentration

• Peaks when traffic heavy• Level seems to rise during

the test

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Why did concentration rise?

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18 g/m3 45 g/m3

Why did concentration seem to rise?

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Background concentration rose in Edinburgh city centre during our test

Conclusions and discussion…• Low-cost sensors offer new possibilities to

investigate exposure to air pollutants• Video can provide context but is difficult to

interpret in a large-scale study• Multiple sensors offer great

opportunities, but the challenge is in working with enormous datasets

• Watch the video at:

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www.youtube.com/watch?v=PafT2SN6GmM