also: ひかりがい
light pollution
Excessive or misdirected artificial light that brightens the night sky and interferes with astronomical observation or ecosystems.
Because of light pollution, you can hardly see the stars in the city.
The observatory was built on a mountain to avoid light pollution.
Standard kanji spelling; the reading こうがい is the most common.
Alternate reading; less common but still used.
Compound of 光 (light) and 害 (harm, damage). A relatively modern term for light pollution.