Copper - Toxicology of Metals - page 518

whereas cuprous(I) oxide and copper are practically
insoluble (WHO, 1998).
Copper can assume the oxidation states 0, +1, +2, and
+3. Cu (0) is very stable, but can dissolve in acids like sul-
furic and nitric acids. The cuprous Cu(I) ion is unstable
in oxidizing environment. Cu(II) is the most abundant
oxidation state in hydrophilic and oxidizing environ-
ments, and the ion is stable in most environments. Cu(III)
is very unstable and of negligible biological signifi cance
(Landner and Lindeström, 1999).

ores pass extensive, concentration processes. The ore is
subject to roasting, converting, and electrolytic refi n-
ing. Instead of converting, a leaching step is used for
the oxidic ores. The secondary copper production,
based on recycled copper, has been steadily increas-
ing, and approximately 38% (in 1993) of the copper
consumption in the Western world was based on
recycled scrap (Landner and Lindeström, 1999).
Another source of copper is based on the production
of other metals (e.g., electrolytic grade copper from the
nickel industry) (Thomassen et al ., 2004).

2 METHODS AND PROBLEMS
OF ANALYSIS

3.2 Uses
The most important uses for copper are in wires
and cables for transmission of electricity. Various
applications within the electronic industry, water
pipes and tubes, vessels and containers, and roofi ng
and facing materials for buildings are other important
applications. Copper compounds are used in wood
preservatives, fungicides, as pigments and antifouling
agents in paints, as nutritional additives to livestock,
and additive to fertilizers. Copper is an important
alloying element, the best known being brass (copper-
zinc) and bronze (copper-tin). Cupro-nickels are used
as coinage material (Landner and Lindeström, 1999).
Copper-beryllium is of particular importance from a
health perspective because of the hazards associated
with beryllium exposure.
There are also some medical uses of copper, like
copper-based alloys used in dental bridges and crowns.
Intrauterine contraceptive devices are also widespread
(Barceloux, 1999).

The introduction of fl ame atomic absorption
spectrometry (FAAS) during the 1960s and later
of electrothermal atomic absorption spectrometry
(ETAAS), inductively coupled plasma optical emission
spectrometry (ICP-OES), and inductively coupled mass
spectrometry (ICP-MS) has simplifi ed and improved
the copper measurements in biological samples. Copper
may be measured in serum without dilution using the
microcup FAAS technique (Odland et al ., 1999). With
either a simple aqueous dilution or acid mineraliza-
tion of serum and urine, copper can be determined by
ETAAS, ICP-OES, and ICP-MS simultaneously with
other essential and/or toxic elements (Chappius et al .,
1992; Correia et al ., 2002; Szpunar et al ., 1997). Total
refl ection X-ray fl uorescence spectrometry has also
recently been shown to be capable of simultaneous
measurements of trace elements, including copper, in
serum (Hernandez-Caraballo and Marco-Parra, 2003).

3 PRODUCTION AND USES 4 ENVIRONMENTAL LEVELS

AND EXPOSURES

3.1 Production
The largest copper reserves are found in Chile,
followed by the United States, Peru, Zambia, and
the Democratic Republic of Congo. The worldwide
exploitable copper ores are approximately 90% of
sulfi dic nature, 9% oxidic, and <1% metallic copper
ores. Principal sulfi dic ores are chalcocite (Cu 2 S) and
chalcopyrite (CuFeS 2 , yellow copper ore), whereas
cuprite is the major oxidic ore (Cu 2 O, red copper ore).
Malachite (Cu 2 (OH) 2 CO 3 , green copper ore) and azur-
ite (Cu 3 (OH) 2 (CO 3 ) 2 , blue carbonite copper) are other
ores of importance. Also crude phosphates used in
the production of phosphate fertilizers may contain
signifi cant amounts of copper.
The primary copper production differs somewhat,
depending on the type of ore. Both sulfi dic and oxidic

4.1 Food and Daily Intake
The daily intake of copper in adults from food
generally varies from approximately 1-2.5 mg,
corresponding to 15-45 µ g/kg body weight in adults

(WHO, 1996).
Organ meats like liver and kidney contain high copper
levels. Fish, fruits, cereals, nuts, and green vegetables
are good sources of copper, whereas meat contains
lower copper levels, and several dairy products includ-
ing milk contain low copper levels (Georgopoulos et al .,
2001; Lönnerdal, 1996; WHO, 1998). WHO (1996) sug-
gested daily requirements of 1.2 mg Cu/day for adult
women and 1.3 mg Cu/day for adult men. Lower die-
tary reference intake of 0.9 mg Cu/day has also been
proposed for adults, with slightly higher intakes during