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Trace Elements in Abiotic and Biotic Environments
A number of studies have been carried out on Cu levels in edible plants, as about
30% of daily intake of Cu by adults in the Europe is from cereals and potatoes.
Monitoring studies carried out in Poland (7000 sample sites) gave the following
geometric mean Cu concentrations (in mg/kg): cereal grains, 3.7; potatoes, 4.5; and
grasses, 5.5 (Kabata-Pendias 2011). These values are fairly similar to those presented
for other countries. Food plants in the United States contain the following amounts
of Cu (range, in mg/kg FW, after Ensminger et al. 1995):
r Vegetable: 0.1–3.2, lowest in celery roots, highest in garlic cloves
r Fruits: 0.3–4, lowest in grapes, highest in avocados
r Cereals: 0.3–13, lowest in oats, highest in rye
r Nuts: 0.2–23.8, lowest in coconut, highest in Brazil nuts
Mean Cu contents in cereal grains vary within the range of 3.6–5.3  mg/kg; the
highest concentration is reported for wheat from Serbia (Škribić and Onjia 2007).
Copper in wheat grains from seven EU countries ranges within 1.3–10  mg/kg
(Eriksson 2001a). Range of mean Cu amounts in grasses from various countries is
2–10 mg/kg, and in clover 7–17 mg/kg. Grass growing along the high traffic roads,
and at 10 km distance from the road, contains Cu within the ranges 5.3–34.4, and
1.2–7.4, respectively (Niesiobędzka 2012).
The mushroom common chanterelles (Cantharellus cibarius) grown in mountains of Poland contains higher amounts of Cu, mean 52 mg/kg, than those grown in
the Baltic Sea coast, mean 30 mg/kg (Falandysz et al. 2012).
14.6 HUMANS
Copper is in almost every cell of the human organism. Its total content in the body
is about 70 mg, of which in the blood 1 mg/L, in the bone 1–25 mg/kg, and in
the tissue 2–10 mg/kg (Emsley 2011). The highest concentrations of Cu are in the
brain and the liver. About 50% of its content is in bones and muscles, 15% in the
skin, 15% in the bone marrow, 8%–15% in the liver, and 8% in the brain (Angelova
et al. 2011).
Following the ingestion of Cu, its levels in the blood rapidly rises. It is predominantly bound to albumin. Copper in all living organisms forms an essential component of many enzymes (cuproenzymes) and proteins. The biochemical role for Cu is
primarily catalytic, with many Cu metalloenzymes acting as oxidases, active in the
reduction of molecular oxygen (e.g., Cytochrome c oxidase and superoxide dismutase).
In the body, Cu shifts between the Cu + and Cu 2+ forms, though the majority of
the body’s Cu is in the Cu 2+ form. Ability of Cu to easily accept and donate electrons
explains its important role in oxidation–reduction reactions, and in scavenging free
radicals. Cytochrome c oxidase plays an essential role in cellular energy, lysyl oxidase, participates in cross-linking of collagen and elastin, which form the connective tissue. The impact of lysyl oxidase helps maintain the integrity and elasticity of
connective tissue in heart and blood vessels, but also plays a role in bone formation.
Copper is necessary in human nutrition for the normal Fe metabolism and the formation of red blood cells. Anemia is a clinical sign of deficiency of both Fe and Cu.