Bøger af David Francisco Camargo Hernández

The extraction of sand is growing every day around the world and is an environmental problem that could lead to the extinction of many of the planet's habitats.it is not only a matter of establishing restrictive policies to prevent the irrational exploitation of sand, which is often illegal, but of putting an end to the mafias that profit from it.sand mining is carried out all over the world, being the most consumed raw material after water.Sand resources from rivers and lakes are not sufficient to meet the demand, so ecosystems are in danger.desert sand and sea sand are not suitable for making concrete, essential for construction and use in technological industries, because the first by its rounded grains as a result of the action of the wind does not mix well and the second because it contains too much sodium that corrodes the metal.