The effects of environmental illumination on melatonin, bodily rhythms and mood states: a review

This review of a wide-ranging and multidisciplinary topic is oriented towards those who have interests in researching into, designing or specifying lighting for working and living environments. The contents have been assembled around six sections to give coherence to such a diverse literature. After the introductory section 1, section 2 outlines the biological pathways mediating melatonin responses to light and section 3 examines the links between light, body rhythms and melatonin secretion. Section 4 reviews the relationship betweebn melatonin response and spectral irradiance and section 5 provides an overview of the association between mood states, pineal activity and light therapy. In section 6 the interrelationship between the pineal gland with other glandular activities is briefly explored and section 7 offers a summary and conclusions. The whole paper suggests that there are many issues to be resolved before convincing generalisations can be drawn about the relationship between lighting, melatonin and mood states.