Attention, chocolate lovers: You may not be able to help yourselves. Swiss and British scientists have linked the widespread love of chocolate to a chemical "signature" that may be programmed into our metabolic systems.
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Hail a cab - but watch out for the pollution
"It was a real surprise to find the extent to which walking resulted in the lowest exposure," said Surbjit Kaur from Imperial College, London.
The researchers studied five modes of transport -- walking, cycling, cars, taxis and buses -- using video cameras and a special counter to measure ultrafine pollutant particles in the atmosphere.
Taxis proved the worst choice with passengers exposed to over 100,000 ultrafine particle counts per cubic centimetre.
"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," Kaur told the journal Atmospheric Environment.
"The fact that taxis are probably on the road for much longer than your average car could cause an accumulation of ultrafine particles," he added.