Kosa causes lots of damage described as in the following and the economical loss due to it is estimated to exceed 700 billion yen yearly: Dust from kosa adheres to things placed outdoors, making them dirty, degrades outdoor visibility, makes the sunlight reaching the ground weaker, obstructs traffic, and adversely affects the health of human beings and animals from inhaling the dust.
主に屋外の物品に砂ぼこりが付着して汚したり、周囲の見通し（視程）や日照を悪化させたり、交通に障害を与えたり、人間や家畜などが砂ぼこりを吸い込んで健康に悪影響を与えたりするなど、多数の被害が発生し、経済的損失は毎年7000億円を超えると推定されている。