If you've ever had to hold your breath on the Paris Metro, then spare a thought for the people who have to spend much of their day working on the network.
A recent report on the air in the Paris Metro system said it was four times worse than the notoriously smoggy Péripherique ring road and perhaps unsurprisingly the latest study claims it poses a health risk to staff.
Metro employees and those working on underground train stations are risking their health while at work, the French health watchdog ANSES concluded.
“There exists respiratory and cardiovascular health risks associated with chronic exposure to fine particles in the air in underground rail enclosures,” the report said.
The source of the dirty air is fine particles of metal than come from the rolling stock and their toxicity is “poorly documented”, the report writes.
Fumes from diesel engines add to the pollution.
As a result of the dangers the health agency has called for “preventative measures” to reduce the exposure of employees to the fine particles.
Those workers most at risk are Metro and train drivers, those who work on safety and maintenance or assistance to passengers, and those working in shops in the underground stations.