Chromium (Cr)

Cr, Krom och kromföreningar, som Cr

 Chromium is a metallic element belonging to the transition metals. This description refers to chromium and chromium compounds.

Uses

Chromium is widely used within industry and is a component in stainless steel where it increases the corrosion resistance of the steel, and it is also used for surface treatment in other metals.¹ Chromium is also used in pigments, paints and within the leather industry for tanning of hides.²

Sources and transportation pathways

Chromium occurs naturally in rocks, soil and in water and is spread in nature through weathering, deposition or leaching. Increased copper levels may occur close to emission sources.³

The largest emission sources to water are wastewater treatment plants and the pulp and paper industry. Emissions to air are substantially lower, with the metal industry being the main emission source, followed by pulp and paper production and waste incineration. In total, Swedish emissions are small compared to many other European countries.

Effects on environment and health

Chromium is considered an essential micronutrient in humans and animals⁴ but high levels may cause damages. Chromium occurs in different states with varying toxicity. From a health perspective, hexavalent chromium is most significant and may cause cancer, mutations or reproductive disorders. Hexavalent chromium, Cr(VI), may also affect the skin and respiratory tract as well as cause issues such as eczema, open sores and nasal irritation.⁵

International agreements and regulations

Chromium is regulated by the UN Convention on Long-range Transboundary Air Pollution (CLRTAP) as well as the EU Drinking Water Directive (98/83/EC) and the Sewage Sludge Directive (86/278/EEC). Limit values for chromium in drinking water is also regulated in the provision of the Swedish National Food Agency.⁶ The UN Protocol on PRTRs and the EU E-PRTR regulation regulate how data on chromium emissions is made available.

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¹ https://gupea.ub.gu.se/bitstream/2077/4233/1/ah2000_21.pdf
² http://www.kemi.se/vagledning-for/konsumenter/kemiska-amnen/krom
³Kotas & Stasicka, 2000. Chromium occurrence in the environment and methods of its speciation. Environmental Pollution, 107: 263-283.
⁴ Pechova & Pavlata, 2007. Chromium as an essential nutrient: a review. Veterinarni Medicina, 52(1): 1-18.
⁵ https://gupea.ub.gu.se/bitstream/2077/4233/1/ah2000_21.pdf
⁶ https://www.livsmedelsverket.se/globalassets/om-oss/lagstiftning/dricksvatten---naturl-mineralv---kallv/slvfs-2001-30-kons-2015-3-webb.pdf