Transport Methods and Inhaled Air Pollution

[Guest guest]

Might be interesting to Peter as we chatted about it the other day.

 

Jo

 

Researchers have discovered that your level of exposure to pollution

can vary according to what method of transport you use, with

travelling by taxis resulting in the highest levels of exposure and

walking the least.

 

Research published in the journal Atmospheric Environment, describes

how the team from Imperial College London and the Health and Safety

Laboratory, Buxton, measured and visualised exposure to pollution

levels, while using a variety of different transport methods for

travelling across London.

 

The researchers looked at five modes of transport, including walking,

cycling, car, taxi and bus, and measured levels of exposure to

ultrafine particles when travelling on them using a newly developed

system that uses in combination an ultrafine particle counter and

video recorder.

 

Ultrafine particles are less than 100 nanometres in diameter and

mainly traffic related. Their small size and large surface area means

it is possible to inhale large quantities which makes them

particularly dangerous.

 

The visualisation system allows video images of individuals'

activities to be played back alongside the ultrafine particle

concentrations they are exposed to. As a result, most activities and

behaviours that cause high exposures can be visibly identified, such

as being trapped on traffic islands and waiting in congested traffic.

 

On average, while travelling in a taxi, passengers were exposed to

over 100,000 ultrafine particles counts per cubic centimetre

(pt/cm3), travelling in a bus resulted in exposure to just under

100,000 pt/cm3, travelling in car caused exposure to 40,000 pt/cm3,

cycling was around 80,000 pt/cm3, and walking was just under 50,000

pt/cm3.

 

Surbjit Kaur, from Imperial College London, and first author of the

paper, said: " It was a real surprise to find the extent to which

walking resulted in the lowest exposure. The higher exposure from

travelling in taxis may come from actually sitting in the vehicle

while being stuck in traffic where you are directly in the path of

the pollutant source. Also the fact that taxis are probably on the

road for much longer than your average car could cause an

accumulation of ultrafine particles. "

 

Dr Mark Nieuwenhuijsen, from Imperial College London, added: " The

particular strength of the system is the visual aspect. The new

monitoring and visualisation system is an effective environmental

risk communication tool that can be used to identify, visualise and

avoid hotspots of pollution. "

 

The study was carried out as part of the DAPPLE (Dispersion of Air

Pollution & Penetration into the Local Environment) project, which

looks to provide a better understanding of the physical processes

affecting street and neighbourhood scale flows of air, traffic and

people, and their corresponding interactions with the dispersion of

pollutants. The project consortium includes the University of

Bristol, the University of Cambridge, Imperial College London,

University of Leeds, University of Reading and the University of

Surrey.

 

DAPPLE is funded by the Engineering and Physical Science Research

Council. Further information about the project and exposure

visualisation samples can be seen at http://www.dapple.org.uk.

 

Tony Stephenson

at.stephenson

Imperial College London

www.imperial.ac.uk/press