Artificial light at night disrupts many people’s circadian rhythm (or light-dark cycles) due to things like electronic device usage, urban light pollution, and working at night (or night shift work). This disruption can alter biological processes that may result in adverse health outcomes. NTP’s Office of the Report on Carcinogens and Office of Health Assessment and Translation plan to conduct health hazard assessments to review cancer and noncancer outcomes.
In March 2016, NTP hosted a workshop to obtain external scientific input on strategies for integrating data across evidence streams and exposure scenarios, data gaps, and research needs. The workshop considered circadian disruptions from:
Participants helped define the scope of the literature-based evaluations, including defining the topic, identifying the most relevant types of studies, and selecting approaches to synthesize across studies. Participants noted it is important to define circadian rhythm before scientists can address circadian disruptions, especially when considering seasonality. Participants also remarked on the need to address the different study designs in published papers, such as the type of light used and a species’ sensitivity to light.
NTP is using the input from the workshop to guide the cancer and noncancer health assessments. More information on the health assessment can be found on the Report on Carcinogens Substances Selected for Evaluation page.