Is prostate cancer incidence worldwide linked to artificial light at night exposures? Review of earlier findings and analysis of current trends.

Widespread use of artificial light at night (ALAN) might contribute to the global burden of hormone-dependent cancers. Previous attempts to verify this association in population-level studies have been sparse. Using GLOBOCAN, US-DMSP, and World Bank 2010-2012 databases, we studied the association between ALAN and prostate cancer (PC) incidence in 180 countries worldwide, controlling for several country-level confounders. The PC-ALAN association emerged marginally significant when year-2012 PC age-standardized rate data were compared with ALAN levels (t = 1.886, p < .1); this association was more significant (t > 2.7; p < .01) when only 110 countries with well-maintained cancer registries were analyzed. Along with other variables, ALAN explains up to 79% of PC ASR variability. PC-ALAN association appears to vary regionally, with the greatest deviations in Central Africa, Small Island Developing States, Southeast Asia, and Gulf States.

The new world atlas of artificial night sky brightness.

Artificial lights raise night sky luminance, creating the most visible effect of light pollution-artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world's land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light-polluted nights.