© Auriane Poillet / City of Grenoble

The Perret Tower transformed into a lighthouse for air quality in Grenoble

I think

Published on 02/09/2022

On 11 February, the top of the Tour Perret will be illuminated live for the first time in the colours of the Atmo index. A beacon for the 1925 International Exhibition of White Coal and Tourism in Grenoble, the Perret Tower is becoming a beacon for air quality a hundred years later, as part of Grenoble's year as European Green Capital 2022.

From "good" to "extremely bad", the Atmo index is graduated in 6 qualifiers to describe the air quality, to which correspond 6 colours: blue, green, yellow, red, purple, magenta. This index is calculated every day by Atmo Auvergne-Rhône-Alpes, the regional air monitoring organisation, for the whole region. It defines the state of outdoor air quality each day for each municipality. It is calculated from the concentrations of five key pollutants: particulate matter (PM10, PM2.5), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2). Already distributed daily on the websites of Atmo Auvergne-Rhône-Alpes, Grenoble-Alpes Métropole, the City of Grenoble and on the smartphone application Air to Go, it now benefits from a new major information relay: the Tour Perret.

From 11 February and for a period of 3 months, the top of the Perret Tower will be illuminated every evening from 7pm to 11pm to inform the people of Grenoble about the air quality forecast for the following day in the city. It will also be visible on public transport shelters. The inhabitants of Grenoble and the surrounding area will thus be able to adapt their outdoor activities, their modes of transport or heating accordingly.

Note that the technical lighting system has been designed to limit electricity consumption with the use of LEDs and to limit the impact on the avifauna present in the Tower.

An experiment that is part of a collective reflection on the display of air quality in public spaces

A regional BVA survey conducted for Atmo Auvergne-Rhône-Alpes in 2019 highlighted the information needs of the region's inhabitants as close as possible to their place of residence.

Thus, the lighting of this emblematic monument in Grenoble aims to facilitate access to and dissemination of local information. A better understanding of air quality is indeed a first step to enable residents to adapt their behaviour to reduce their contribution to pollution and preserve their health.

A partnership project as part of Grenoble's European Green Capital year 2022

The transformation of the Perret Tower into a lighthouse for air quality in Grenoble is a project led by Atmo Auvergne-Rhône-Alpes. It benefits from the technical support of the City of Grenoble and Grenoble-Alpes Métropole.

What about its financing? In 2021, the French Council of State ordered the French government to pay a financial penalty, due to actions deemed insufficient to comply with the regulatory air quality values. Several associations and organisations involved in the fight against air pollution have benefited from this penalty payment. Atmo Auvergne-Rhône-Alpes decided to allocate part of this amount to the lighting of the Perret Tower, with the aim of informing the inhabitants more widely and enabling them to anticipate their behaviour.

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