Abraham Haim

Abraham Haim

University of Haifa, Israel

Title: Exposure to artificial light at night (ALAN) - metabolic responses including obesity and diabetes


Abraham Haim Full-professor (1996) UH, Israel, completed Ph.D. from HUJ, Israel, Postdoctoral MRI, UP, South Africa, (Ecophysiologist Chronobiologist). He studied thermoregulation in desert-adapted rodents, revealing the importance of non-shivering-thermogenesis, as a mechanism compensating for their lower metabolic-rates, seasonality and daily-rhythms of body-temperature and metabolic-rates. Realizing that darkness at night is disappearing he moved to study the impact of light-pollution on rodents' and human health issues. Head of several departments, as a dean he established the faculty of Natural- Sciences, vice-president, "The Israel Lighting association". Published over 160-papers in pre-reviewed journals and is one of the authors of the book "Light Pollution as New Risk Factor for Human Breast and Prostate Cancer" (Springer).


Throughout evolution, terrestrial organisms were adapted to light/dark cycles of 24h which reflect the rotation of our plant on its axis. These cycles are used by the different organisms for the entrainment of their endogenous biological clock. Furthermore, the movement of the planet around the sun results in seasonality. The most environmental dramatic change that took place on our plant starting some 140 years ago is the transformation of electric energy into artificial light thus eliminating the light/dark cycles and seasonality, where photophase does not differ any more between seasons. No doubt that this change brought with it a major change in human lifestyle however, it takes time before the negative impacts, resulting in an increase in human health risk can be assessed. For several years we studied the relations between exposure to Artificial Light at Night (ALAN) and Metabolic-disorders. In the last decays with the introduction of short wavelength illumination (SWL) a further increase in health risk was noted. Results of several experiments carried out on laboratory animals showed that exposure to ALAN suppresses the Pineal-gland melatonin (MLT) production, a hormone produced under dark conditions during the night. As in our research centre we have been studying a diurnal rodent, the fat sand rat Psammomys obesus, as a model for humans, we can show that ALAN of SWL interferes with metabolic processes we suggest that these changes are through epigenetic modifications. If this is the case, if this is the case the nexus SWL-ALAN via MLT-suppression should be studied.