# What are heavy metals?

May 2, 2017

Density values are greater than $5 \frac{g}{c {m}^{3}}$

#### Explanation:

Heavy metals are defined as metallic elements that have a relatively high density compared to that of water.

Heavy metals have densities greater than $5 \frac{g}{c {m}^{3}}$. Many are toxic when accumulated into animal bodies. Some examples of heavy metals are arsenic, cadmium, chmomium, lead, nickel, etc.

Despite that fact that heavy metals are naturally occurring elements that are found in many different parts of the earth’s crust, most environmental pollution and human exposure result from anthropogenic activities such as mining and smelting operations, industrial production and use, and domestic and agricultural use of metals and metal-containing compounds (Tchounwou et al., 2012).

Reference:

Tchounwou, P.B., Yedjou, C. G., Patlolla, A. K., Sutton, D. J. (2012). Heavy Metal Toxicity and the Environment. Molecular, Clinical and Environmental Toxicology. Luch, A. (ed.) Springer, Basel, Switzerland.