Why do we use different concentration units – Química 10º

Most people are unaware of the true value of water, because it is available at all times, except in extremely dry areas and during drought season; circumstances that make us reconsider the importance of this liquid. We use water in countless everyday activities such as showering and cooking, besides being dependent on it because we would not be able to survive without it; being 60% of the mass of the human body. The multiple uses of water originate mainly from its capacity to form aqueous solutions that help dissolve many solids and some liquids. Water remains in a liquid state at room temperature because of the unique properties of its molecules; many chemical reactions and most biological processes occur in an aqueous environment. In spite of the fact that water covers 70% of the planet, it is uncommon to find pure water in nature. Water from the sea and found in reservoirs contain dissolved minerals and polluting agents, such as fertilizers and industrial waste. Additionally, water can contain chlorine and lead, if the pipes that transport the substance are very old. Bogota river is one of the most polluted in Colombia. The main pollution sources are household and industrial disposal waters that fall directly into the watercourse of the river. Furthermore, the river presents high concentrations of toxic substances, mainly cadmium, chromium and lead. These high pollution levels of Bogota river have vastly damaged the flora and fauna, as well as the quality of the crops watered with this stream and have also caused health detriments in the human population directly exposed to the contaminated water.