International Commission on Non-Ionizing Radiation Protection (ICNIRP) has identified a lack of consensus among public health officials about whether SWL from artificial sources disrupts circadian rhythm. Research conflicts on physiological effects of SWL exposure The neuroendocrine system is particularly sensitive to SWL. In addition, SWL might reduce evening sleepiness by an alerting effect, suppress melatonin levels, and consequently affect sleep quality and duration, which over time may negatively affect health.