Sustainable residential lighting practices and light pollution

LED lighting is widely considered as a promising solution to improve the energy efficiency of residential lighting due to its higher luminous efficacy compared to conventional residential lighting and potential for having an even higher efficacy in the future. High luminous efficacy reduces the electrical energy required for lighting service but the lighting products of high luminous efficacy may pose other environmental concerns as a trade-off for energy savings. In residential lighting, this kind of trade-off was seen in (compact) fluorescent lamps containing mercury, which is a toxic heavy metal. Recently, a potential environmental concern has been identified: light pollution caused by artificial lighting. Light pollution is defined as the sum of all adverse impacts of artificial light. It may mean the wasted energy, the potential negative impacts of light on human health or ecosystems, light trespass, or the sky glow hampering the astronomical observations. Light pollution is associated with several health issues from retinal damage to cancer and obesity. This paper aims to review the scientific evidence of the potential negative impacts of artificial light on human health, including indoor and outdoor lighting, also in residential areas. Other forms of light pollution, such as impacts on fauna and flora and the astronomical light pollution are excluded from the scope of the current study.