Istituto di Scienza e Tecnologia dell'Inquinamento Luminoso, Via Roma 13, I-36106 Thiene, Italy.
J Environ Manage. 2011 Oct;92(10):2714-22. doi: 10.1016/j.jenvman.2011.06.029. Epub 2011 Jul 13.
Light pollution is one of the most rapidly increasing types of environmental degradation. Its levels have been growing exponentially over the natural nocturnal lighting levels provided by starlight and moonlight. To limit this pollution several effective practices have been defined: the use of shielding on lighting fixture to prevent direct upward light, particularly at low angles above the horizon; no over lighting, i.e. avoid using higher lighting levels than strictly needed for the task, constraining illumination to the area where it is needed and the time it will be used. Nevertheless, even after the best control of the light distribution is reached and when the proper quantity of light is used, some upward light emission remains, due to reflections from the lit surfaces and atmospheric scatter. The environmental impact of this "residual light pollution", cannot be neglected and should be limited too. Here we propose a new way to limit the effects of this residual light pollution on wildlife, human health and stellar visibility. We performed analysis of the spectra of common types of lamps for external use, including the new LEDs. We evaluated their emissions relative to the spectral response functions of human eye photoreceptors, in the photopic, scotopic and the 'meltopic' melatonin suppressing bands. We found that the amount of pollution is strongly dependent on the spectral characteristics of the lamps, with the more environmentally friendly lamps being low pressure sodium, followed by high pressure sodium. Most polluting are the lamps with a strong blue emission, like Metal Halide and white LEDs. Migration from the now widely used sodium lamps to white lamps (MH and LEDs) would produce an increase of pollution in the scotopic and melatonin suppression bands of more than five times the present levels, supposing the same photopic installed flux. This increase will exacerbate known and possible unknown effects of light pollution on human health, environment and on visual perception of the Universe by humans. We present quantitative criteria to evaluate the lamps based on their spectral emissions and we suggest regulatory limits for future lighting.
光污染是环境恶化中增长最快的类型之一。它的水平已经在以星光和月光提供的自然夜间照明水平为基础呈指数级增长。为了限制这种污染，已经定义了几种有效的实践方法：使用照明灯具的屏蔽来防止直接向上的光，特别是在地平线以上的低角度；不过度照明，即避免使用高于任务所需的照明水平，将照明限制在需要的区域和使用时间内。然而，即使在达到最佳的灯光分布控制并且使用适当的光量后，由于从照明表面反射和大气散射，仍然会有一些向上的光发射。这种“残余光污染”的环境影响不容忽视，也应该加以限制。在这里，我们提出了一种新的方法来限制这种残余光污染对野生动物、人类健康和恒星可见度的影响。我们分析了包括新型 LED 在内的常见外部使用灯具的光谱。我们评估了它们的排放与人类眼睛感光器的光谱响应函数之间的关系，包括光适应和暗适应以及“褪黑素抑制”波段。我们发现，污染的程度强烈取决于灯具的光谱特性，对环境更友好的灯具是低压钠灯，其次是高压钠灯。污染最严重的是具有强烈蓝色发射的灯具，如金属卤化物和白色 LED。从现在广泛使用的钠灯向白色灯（金属卤化物和 LED）的迁移，如果安装的光通量相同，将会导致暗适应和褪黑素抑制波段的污染增加超过五倍，超过目前的水平。这种增加将加剧已知和可能未知的光污染对人类健康、环境以及人类对宇宙视觉感知的影响。我们根据光谱发射提出了评估灯具的定量标准，并建议了未来照明的监管限制。
