Circadian dynamics provides a novel method for assessing and mitigating urban light pollution

Practical solutions for light pollution from Artificial Light at Night (ALAN) that balancing urban lighting with biological well-being remain challenging. Here we used a mammalian circadian-clock model to systematically explore how the intensity and duration of ALAN affect circadian rhythm through its dynamical behavior. The results show an apparent intensity-dependent transition from stable to instable responses in phase shift and amplitude as exposure extends later into the night. This suggests that circadian dynamics can be used as a model-based framework for further investigating urban-lighting strategies and developing exposure-specific guidance.