From 10:00 to 10:30 p.m., the students in Woodlawn’s Earth Force Group want everyone to dim or turn off unnecessary lights, and draw their shades or curtains to prevent light pollution. The half hour of observance coincides with Earth Day today, Arlington’s Green Expo on Saturday, International Dark Sky Week and, according to sixth-grader Samara Cathirell, “the peak migration of birds over our region.”

“Studies have linked various cancers to over-exposure to artificial lighting, including breast and prostate cancer,” said the Earth Force press release credited to Samara. “Some amphibians have been shown to come out later to feed and are missing their prey opportunities. Millions of birds die each year by flying into tall artificially lit buildings. Algae continues to grow excessively at night under the artificial lights polluting streams, and nitric oxides and C02 (a greenhouse gas) and SO2 are building up contributing to pollution.”