Abstract: Artificial lighting has transformed the outdoor nighttime environment over large areas, modifying natural cycles of light in terms of timing, wavelength, and distribution. This has had widespread benefits and costs to humankind, impacting on health and wellbeing, vehicle accidents, crime, energy consumption and carbon emissions, aesthetics, and wildlife and ecosystems. Here, we review these effects, particularly in the context of ongoing developments in the extent of artificial lighting and in the prevalent technologies being employed. The key issue that emerges is how best to maximize the benefits of artificial nighttime lighting whilst limiting the costs. To do so, three main strategies are required. First, important knowledge gaps need to be filled. Second, there is an urgent need to connect the research being conducted in different disciplines, which to date has been very disjointed. Third, it is imperative that much firmer and well-developed links are made between research, policy, and practice.

Abstract: Based on the abundant studies available on humans showing clear associations between rapid environmental changes and the rate of neoplasia, we propose that human activities might increase cancer rate in wild populations through numerous processes. Most of the research on this topic has concentrated on wildlife cancer prevalence in environments that are heavily contaminated with anthropogenic chemicals. Here, we propose that human activities might also increase cancer rate in wild populations through additional processes including light pollution, accidental (for example, human waste) or intentional (for example, bird feeders) wildlife feeding (and the associated change of diet), or reduction of genetic diversity in human-impacted habitats. The human species can thus be defined as an oncogenic species, moderating the environment in the way that it causes cancer in other wild populations. As human impacts on wildlife are predicted to increase rather than decrease (for example, in the context of urbanization), acknowledging the possible links between human activity and cancer in wild populations is crucial.