Isère remains among the most exposed departments

What is the assessment of air pollution in the Auvergne-Rhône-Alpes region (and more specifically in Isère) in 2021? Atmo Auvergne-Rhône-Alpes delivers its first conclusions, which confirm a downward trend observed since 2007. Even if some rates increased between 2020 and 2021, a fairly logical consequence of the Covid crisis and periods of health restriction that she trained.

Although the air quality has improved since 2007, pollution is still present in the Grenoble “cuvette”. © Leo Graff – Place Gre’net

Thus, since 2007, nitrogen dioxide has dropped by 43%, while fine particles PM10 and PM2.5 are, respectively, at – 47% and – 62%. But these, mainly due to wood burning “non-performing“, increased between 2020 and 2021. As for nitrogen dioxide caused by automobile traffic, its rates remained fixed between 2020 and 2021, after a drop of more than 10 points between 2019 and 2020.

However, not all indicators are down. Thus, ozone shows an increase of 6% between 2007 and 2021, largely due to a period of increase of nearly 20 points between 2016 and 2018. This pollution has since begun an equally spectacular drop. In particular in 2021, a year marked by a cool and rainy summer, while the ozone develops thanks to the sunshine and high temperatures.

Air pollution: Isère remains one of the most exposed departments.  Grenoble's air quality can also be affected by desert sand.  © Place Gre'net

Grenoble’s air quality can also be affected by desert sand. © Place Gre’net

However, the (almost) general drop in pollutants in the atmosphere does not prevent certain departments in the region from experiencing pollution peaks, and the related prefectural alerts. There were 25 of these in 2021, compared to 31 in 2020 and 47 in 2019. Here again, Atmo highlights the significant drop over time: in 2011, 93 days of pollution vigilance activation were activated. The value is nonetheless fluctuating, with significant rebounds at times.