Effects of daylight and artificial light on melatonin suppression in educational environments

Daylight in indoor environments not only allows to achieve reductions of energy consumption, but it is even more important because of its effects on human beings. In particular, it ensures a high comfort in carrying out all the human activities and is also important to the circadian rhythm regulation; therefore it results necessary to evaluate the entrance of natural light in indoor environments both in qualitative and quantitative terms. An analysis of the characteristics of daylight and in an indoor environment is here carried out, by comparing SPDs and CCTs of the natural source (sky) during typical days with contemporaneous measurements of spectral irradiances and CCTs detected at the eyes level. From measures carried out, the effects of melatonin suppression during the day according to the procedure proposed by Rea et al, were calculated.