Beyond Environmental Sustainability: A Conceptual Framework for Valuing Circadian Disruption

Circadian rhythm disruption caused by artificial light at night (ALAN) and shift work has been linked to several adverse health outcomes, including cancer, cardiovascular disease, and metabolic disorders. Despite increasing biological and epidemiological evidence, these health costs have not been formally framed as environmental or economic externalities. To address this, a narrative review of biological, epidemiological, and economic literature on circadian disruption from ALAN and shift work was conducted to propose a conceptual framework for valuing circadian disruption as an externality, while examining health impacts, economic valuation methods, and policy interventions. Both exposures disproportionately affect lower-income populations, who have limited control over their light environment and are overrepresented in shift work occupations. Economic valuation methods such as the value of statistical life are, in principle, applicable to this externality but remain largely unapplied, reflecting both a lack of outcome-specific causal estimates and an absence of dedicated willingness-to-pay studies. Corrective policies such as spectral lighting regulations, Pigouvian taxes on ALAN-generating activities, and shift work scheduling standards, could internalize these costs but require reliable economic valuation data and distributional impact assessments. Interdisciplinary research integrating chronobiology and economics is needed to translate this conceptual framework into evidence-based policy.