Sensor could aid construction of real-time pollution maps

A new sensor technology could be used to construct real-time pollution maps of cities that would be useful in understanding the health implications of local emissions and informing policy.

Duvas Technologies’ system is based on ultraviolet-absorption spectroscopy, which can detect a range of pollutants simultaneously — replacing the need for the whole set of different instruments currently used to monitor local emissions.

Currently, more than one billion people a year suffer from respiratory diseases associated with pollution and, according to the World Health Organization, more than three million a year die from its effects.  

Indeed, the UK government is currently facing the threat of a £300m fine as a result of London repeatedly falling short of EU air-pollution targets.

’In order to be able to manage a problem, you have to be able to measure it well,’ said Duvas scientist Steven Wilkins.

‘At the moment, the situation in London is that you have a very limited number of sites trying to put together a picture of what is happening across the capital.’

To test the performance of its sensors, Duvas turned to the National Physical Laboratory (NPL), which came up with a novel gas-dilution technique to simulate the trace-emission gases found at ambient concentrations in the environment.

The results showed that the sensors were able to respond to emissions at the level of parts per billion on a second-by-second time frame.

Once in place, the network of sensors could be used by councils to inform traffic and environmental policy, and to better understand health implications.

‘If you put our devices behind a set of traffic lights, you can see the individual pulses of pollution coming from the traffic as it pulls away. With existing methods, very often it’s averaged away and you lose sight of what’s causing the problem,’ Wilkins said.

’One challenge, however, will be in integrating the wealth of data that such a network of sensors could deliver and applying it in a useful way.

‘You can have a very large number of sensors of different types deployed and actively monitoring… the data comes back to a central server, so you can view maps of pollution overlaid with Google Earth or Google Maps, or in real time,’ Wilkins said.