> River sand is preferable to coastal sand, partly because coastal sand has to be washed free of salt. But coastal sand does get used, especially when builders

> River sand is preferable to coastal sand, partly because coastal sand has to be washed free of salt. But coastal sand does get used, especially when builders take shortcuts, leading to buildings that have shorter life spans and pose greater risks for inhabitants. Wow, that's all the article said about this? It's the crux of the matter. Corrupt chinese construction projects may use cheaper coastal sand, resulting in so-called "Tofu-Dreg" buildings (豆腐渣工程) where the salt in the sand has corroded the rebar and the building just falls down. As I understand it, it's a major concern in China. Google for it.