New traffic radar monitors car pollution in Paris

A new kind of traffic monitor has appeared on the streets of Paris - but this one monitors pollution levels rather than driver behaviour.

The device, at the top of boulevard Diderot, near Place de la Nation in the 12th arrondissement, is equipped with a laser that measures levels of exhaust fumes in real-time.

The laser performs 20,000 scans per second, and the results - showing levels of nitrogen oxides, fine particulates, carbon dioxide, carbon monoxide and hydrocarbons - appear almost simultaneously on a computer,

City officials said it is an anonymous data collection tool that will allow them to more accurately study pollution levels.

Tests of the radar in other European countries reveal that diesel emission standards have been significantly exceeded.