A rising risk to human health: assessment of light pollution on two dark sky regions of Portugal

• Autor(a) principal: Lima, Raul Cerveira
• Data de Publicação: 2014
• Outros Autores: Cunha, José Pinto da, Peixinho, Nuno
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/26018
• topic: Light pollution; Dark skies

Bad public and private artificial light planning is the main cause for light pollution (LP). Night illumination is part of modern societies, reaching increasing levels with consequences on various fields that only recently began to be studied. Residents of large cities are almost totally deprived from a starry night. UNESCO, UNTWO and IAU’s Declaration in Defence of the Night Sky and the Right to Starlight state that “an unpolluted night sky that allows the enjoyment and contemplation of the firmament should be considered an inalienable right equivalent to all other socio-cultural and environmental rights. Hence the progressive degradation of the night sky must be regarded as a fundamental loss” and that “the intelligent use of artificial lighting that minimizes sky glow and avoids obtrusive visual impact on both humans and wildlife should be promoted. This strategy would involve a more efficient use of energy so as to meet the wider commitments made on climate change, and for the protection of the environment”(Marín & Jafari, 2007).The observation and study of the night sky both at professional and casual or amateur levels is the first to be affected by light pollution thus being the primary reason to study LP until recently. However, other LP effects are already known to affect the human being such as modifications of the circadian rhythm(Stevens, 2006). More recent studies suggest LP as a risk factor for human breast and prostate cancer(Haim & Portnov, 2013). Other direct and indirect effects on the environment include natural resources consumption and effects on biodiversity, namely nocturnal fauna(Rich & Longcore, 2005).The creation of dark-skies protected areas is one form to preserve the night sky of some regions that still have a good dark sky quality. It is also a way to draw the attention of public and stakeholders to this growing problem. More than a local effect caused mainly by large urban centres, light pollution propagates to regions that are tensor more kilometres away from those populated regions, affecting places once with good night sky quality even a few years ago. Two examples of regions in Portugal that offer good dark skies are, at the north of the country, the Peneda-Gerês National Park and, at the south, the Alentejo’s region of Alqueva, both commonly known to have good dark skies but that have not been previously measured. The latter got its classification as «dark sky reserve» based on the values of night sky brightness obtained for this work.