Pittsburgh Becomes First 'Dark Sky' City in Eastern U.S.

Pittsburgh became the first city in the eastern U.S. to adopt a 'dark sky' policy, reports Josyana Joshua, " meaning that it will switch to lower wattage LED bulbs and add shades along bridges, roads and other public areas" to reduce light pollution and energy use from public lighting. 

Although it joins 34 other 'dark sky' communities that have committed to reduced lighting guidelines, "Pittsburgh will be the first city in the world to follow the International Dark Sky Association’s new values-centered outdoor lighting, which means it will follow the group’s more comprehensive suggestions surrounding wattage and color temperature as well as when and how to keep lights on." Dark sky advocates say light pollution disrupts ecosystems and natural processes that depend on light cues, writes Joshua. "It can also confuse the natural 24 hour day/night cycle for humans — a darker sky has been found to have positive effects on mental health, with stargazing and less blue light playing a part."

Despite concerns about safety, research from England and Wales shows that street lighting reductions did not negatively affect crime or car crash rates. Since Pittsburgh's announcement, other eastern cities and states have pushed forward dark sky initiatives of their own.