According to component analyses of kosa conducted in 2001 at the three typical kosa source places (the western area of China, the northern area of China and the Loess Plateau) in Asia, the kosa included, in the larger mass order, silicon (24 to 30 percent), calcium (7 to 12 percent), aluminum (7 percent), iron (4 to 6 percent), potassium (2 to 3 percent) and magnesium (1 to 3percent).
2001年にアジアの黄砂発生源を3つに区分（中国西部・中国北部・黄土高原）して行われた黄砂の成分分析では、質量が多い順にケイ素が24-30%、カルシウムが7-12%、アルミニウムが7%、鉄が4-6%、カリウムが2-3%、マグネシウムが1-3%ほどを占めた。