Zn, Zink och zinkföreninger, som Zn
Zinc and compounds
Zinc is a common, bluish or light grey metal that is a solid at room temperature and that has strong anti-corrosion properties. This description refers to zinc and zinc compounds.
Zinc coatings, by galvanization (zincification), are used as corrosion protection to resist rust and extend the lifespan of other metals. More than half of all zinc use is due to galvanization. Zinc is also used in production of brass and as raw material in the metal industry.1 2 3
Sources and transportation pathways
Zinc occurs naturally in the environment in various minerals and in varying concentrations. China is the leading zinc producer in the world, followed by Peru. Zinc is also extracted in Sweden.
Combustion of biomass for heat and electricity production is the single largest emission source of zinc in Sweden today. Tyre and brake wear are also significant sources of zinc emissions to air. Total zinc emissions to air have decreased by 40 % since the 1990’s.4 Corresponding trends can be seen in lakes, rivers and in moss.5 The pulp and paper industry is the single largest source of zinc emissions to water, followed by smaller emissions from wastewater treatment plants.6 Diffuse zinc emissions to water originate largely from the transport sector. Sweden’s zinc emissions both to air and water are relatively small compared to other European countries.
Effects on environment and health
Zinc is a nutrient needed in small amounts in animal and plants, but high levels may be toxic. Zinc is a component in several enzymes and is for example needed in the metabolism process.7 Zinc is the second most common trace element in the body second to iron.8 The general population is exposed to zinc mainly through food.
High concentrations of zinc have shown to be harmful to aquatic organisms and may cause behavioural and reproductive disorders.9 During welding of galvanized steel, fumes are produced that may cause metal fume fever and symptoms including chills, fever and nausea.10
International agreements and regulations
Zinc is regulated by the UN Convention on Long-range Transboundary Air Pollution (CLRTAP) and the EU Sewage Sludge Directive (86/278/EEC). The UN Protocol on PRTRs and the EU E-PRTR regulation regulate how data on zinc emissions is made available.
8McCance, R. A. & Widdowson, E. M.. 1942 The absorption and excretion of zinc. Biochem. J. 36:692-696.
9Lefcort, H.; Meguire, R. A.; Wilson, L. H.; Ettinger, W. F. Arch. 1998. Heavy metals alter the survival, growth, metamorphosis, and antipredatory behavior of Columbia spotted frog (Rana luteiventris) tadpoles. Archives of Environmental Contamination and Toxicology.35: 447-456.