The Arve Valley is particularly sensitive to pollution due to the fact that "it’s V-shaped – makes it quite encased, so when we have high pressure it basically puts a lid on the valley", explained Chamonix mayor, Eric Fournier, for The Guardian.
Moreover, in addition to the 10,000 residents, Chamonix's huge popularity brings around five million tourists every year, all of them practising various activities that leave a carbon footprint.
Air quality monitoring, carried out by the association Atmo Auvergne-Rhône-Alpes, demonstrates a significant presence of several pollutants: fine particles (PM10), especially in winter, nitrogen oxides (NOx), polycyclic aromatic hydrocarbons (PAHs) and ozone (especially in summer).
The Atmosphere Protection Plan for the period 2019-2023 was revised and approved on April 29, 2019.
The revised plan sets ambitious targets for meeting the air quality limit values at the end of the plan. You can see the whole Atmosphere Protection Plan for the Arve Valley here (French only).
In an attempt to fight pollution, the speed limit is lowered in the Arve Valley from 130 to 110 km/h on the highway, and from 110 to 90 on the departmental.
The measure took effect on November 1st 2019 and will last until March 31st, 2020.