Extreme cold, almost no wind and temperature inversion at altitude… This meteorological cocktail that prevents the dispersion of pollutants should lead to an increase in PM10 levels (fine particles larger than 10 microns), this Saturday, throughout the Ile-de-France. According to Airparif forecasts, they could exceed the “information and recommendation threshold” set at 50µg (micrograms) per cubic meter of air but without exceeding the 80µg/m3 threshold… Which leads to the activation of the ‘ alert.
Generated mainly by industrial activity, heating and road traffic, fine particles can cause respiratory or cardiovascular difficulties in frail people. On the eve of the pollution episode, the health authorities therefore recommend that vulnerable populations favor short outings and avoid proximity to areas with high road traffic, throughout the day on Saturday.
On the traffic side, the Paris police headquarters had to remind, this Friday at the end of the afternoon, the instructions for motorists for overtaking day. There are no binding measures. The “information” procedure only provides good practice recommendations: postpone non-essential travel, favor clean vehicles or carpooling, get off the roads…
As with previous PM10 warnings (not uncommon in winter), drivers should be asked to reduce their speed by 20km/h from the usual limits on all major roads in the region. HGVs in transit will be encouraged to bypass the central area of Ile-de-France.
Stricter traffic restrictions – such as the “ differentiated circulation which prohibits the use of vehicles other than Crit’Air 0, 1 and 2- are put into effect only after the alert threshold has been exceeded… They can also be decreed in the event of the information threshold being exceeded for several consecutive days. This scenario is not expected to occur this weekend in Ile-de-France. Airparif expects an improvement in the situation the day after the day the thresholds have been exceeded.
