2023-08-25 00:06:22
Our retina receives light stimuli by photoreceptor cones, which allow vision, but also by photosensitive ganglion cells, involved in the regulation of many behaviors : sleep and melatonin secretion, maintenance of the circadian rhythm in our body, or our cognitive performance. Various laboratory studies in humans and animals demonstrate that these latter cells, by their activation anormale via l’illumination nocturneare susceptible to desynchronize the internal clockitself responsible for sleep disturbances, mood or cognitive disturbances (memory problems, decreased alertness, etc.).
Thus, studies have shown that night workers have disturbed circadian rhythms and are more at risk of developing certain pathologies: cancers (breast for example), obesity, hypertension, depression. The effect of outdoor artificial light on city dwellers is more difficult to quantify, but some epidemiological studies suggest a risk increased cancer or cardiovascular disease in urban dwellers exposed to outdoor light pollution. Furthermore, living in an urban environment more polluted by night light has been correlated with a more severe and longer Covid infection.
The exposure of teenagers, heavy users of screens, including late at night, also raises questions, inevitably generating a desynchronization of the internal clock and a sleep debt.
Another problem: the news artificial light sources being very efficient (they have a strong emission of blue light in the 380-500 nm band, close to ultraviolet radiation), experimental arguments suggest that they might be phototoxic for the retina, in particular the macula, and thus be a risk factor for AMD (no prospective study has however shown an association between cumulative exposure and ocular pathologies).
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#Light #pollution #double #negative #impact #health
