The thing

Measuring air quality with a doll

3 min
Text Lise Wouters
Image Jesse Willems

Flanders is characterised by urbanisation and heavy traffic. Motorised traffic is a major cause of poor air quality, which can cause health problems such as asthma and chronic cardiovascular disease. CLAIRE (Clean AIR For Everyone) researched the state of Flemish air using two dolls. 


CLAIRE was used to study the effect of slow streets on air quality. Slow streets are car-free and ideally have green infrastructure such as trees and plants. Previously, trees and plants have already been shown to act as a filter that can trap particulate matter, thereby improving air quality. Slow streets could therefore be a better alternative to roads with heavy car traffic.  


‘We had to come up with a way to study air quality and the effect of slow streets on it, without emitting particulate matter ourselves’, Roeland Samson says, professor of bioscience engineering at UAntwerp. ‘That’s how we came up with the idea of using a pram.’ 


The births of Claire and Gilbair 


Samson and his team stowed a pram full of measuring equipment. ‘Those devices measure particulate matter, ultrafine particulate matter and soot’, Samson explains. ‘So by walking around with it, you get a better idea of the air quality along your route.’

The pram not only served as a mobile measurement system; it also helped estimate young children’s exposure to traffic-related pollution. Toddlers and infants are often literally closest to the source of pollution, namely the exhaust pipes of cars. Earlier research had already shown that pollution at this height is greater than at the breathing height of an adult. 


And so Claire was born, the mascot of the eponymous project. Soon hundreds of volunteers signed up to walk with Claire. To give everyone a chance to participate in this citizen science project, Claire was soon joined by a little brother: Gilbair.  

The volunteers’ established walking route included a busy road, with a lot of car traffic, and a slow street. In addition, the researchers also studied a road lined with trees where cars were allowed to drive. Along the entire route, a number of variables were measured every ten seconds. 


Collecting mileage and data 


Thanks to all the volunteers, a lot of walking was done in 35 weeks of walking: 568 walks with a combined total of 3,680 kilometres. That’s roughly from Antwerp to Porto and back. But more importantly, a lot of data was collected.  

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By walking around with the doll, volunteers helped us discover the quality of the air on their route. 

Roeland Samson

The researchers went to work with all the data and found that air quality is indeed better on slow streets. But that’s not all: 


  • On a busy road, the air is noticeably more polluted.  

  • The cleanest air can sometimes be found just beyond the roadside: green infrastructure can act as a buffer against pollutants and has a cooling effect. 

  • At every place measured, the World Health Organization guidelines for particulate matter were exceeded.  


Thanks to the dolls Claire and Gilbair, scientists now have a better understanding of the health effects of busy roads and slow streets. The project was carried out as part of Nature Smart Cities, an international project, which supports local decision-makers in building and maintaining green infrastructure. 

Read more about this project

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