POLLUX - Nocturnal light pollution: how extensive is it? What are the effects on biodiversity? What legislative measures need to be taken? (2017)

Scientific coordinator: Thierry Lengagne (LEHNA) – thierry.lengagne@univ-lyon1.fr
Disciplines: Life Sciences – Geography – Environmental Law
Laboratories: LEHNA – EVS
Partner: Plaine de l’Ain community of municipalities


Nocturnal artificial light is essentially emitted by urban areas and road infrastructure. This phenomena is constantly increasing and has significant biological consequences. In effect, night-time periods regulate the synthesis of melatonin, the key hormone which synchronises a multitude of physiological processes (metabolism, growth, stress and immunity in the majority of animals). Although effects on natural populations are to be expected, approaches taken so far are difficult to transpose to the natural environment as they does not take into account the intensity of light actually borne by the organisms in natural conditions.

The aim of the proposed project is to produce a dynamic mapping of nocturnal artificial light in a study area situated northeast of Lyon, by measuring the relative contribution of the light halo of urban areas and direct lighting from road infrastructure, and to determine the biological effects of the nocturnal artificial light on common amphibians in this area. The results obtained will make it possible to precisely model the risks of exposure to nocturnal artificial light for biodiversity at the local level. Based on the mapping of nocturnal artificial light, we will seek to measure the application of regulations on light pollution at the local level and existing obstacles to their implementation. We will then analyse if the requirements of the regulations in force are adequate for future towns and cities, or if they can be improved. Innovative examples of voluntary measures to reduce light pollution and foreign regulations will be taken into account to this end and tested in situ thanks to collaboration with a practitioner (the Plaine de l'Ain community of municipalities with the ACMUTEP project), which will make it possible to conduct full-scale tests. Prospective work will be carried out to establish how environmental law should evolve to support the intelligent towns of tomorrow in terms of managing lighting at night.