The importance of nickel (Ni) in the environment is an issue that is gaining broader recognition. While nickel is an element essential for plants, it is also a heavy metal. Nickel is a component of nine metalloenzymes, including urease, which participates in urea hydrolysis. It also helps some plants to protect themselves against pathogens and herbivorous insects. There are many sources of Ni in the environment, which can be a problem because at higher concentrations this element is toxic to plants and other living organisms. Therefore, standards have been defined for the Ni content in air, water, soil and plants. Its content is monitored in the air. More and more frequently, attention is paid to this element as an allergen in humans. In the world, attempts have been made to phytoextract nickel from contaminated soils using nickelphilous plants, the so-called hyperaccumulators, and even to recover the metal from these plants by so-called phytomining. On the other hand, nickel-containing fertilizers are marketed and used in cases of nickel deficiency in plants. In industry, this element is primarily used for the production of steel and alloys. The most recent application of nickel is related to graphene, which was invented 10 years ago. Although nickel contamination does not occur in Poland, we cannot rule out this risk in the future. Thus, it is important to monitor the fate of nickel in the environment.

20.2.2015