Chemistry Reference
In-Depth Information
World production of cadmium (metric tons) for years 1900-2002
25 000
World production
20 000
15 000
10 000
5 000
0
Years
FIGURE 1
World production of cadimium (metric tons) for years 1900-2002
TABLE 1
Cadmium Global Supply 2002 (22,000
Metric Tons)
discrepancies were common in the past, they may still
occur if adequate quality control is not used in sam-
pling and chemical analysis.
Data from reliable analyses performed in several
countries (Elinder, 1985a; WHO/FAO, 2003) indicate
that most foodstuffs have Cd concentrations in the
range 0.005-0.100 mg/kg (mean values, wet weight;
see Table 2). Certain foods (e.g., kidney and oysters)
may contain much higher concentrations. Cadmium
concentrations in brown rice in Japanese noncontami-
nated areas are presently usually 0.01-0.2 (average,
0.06) mg/kg (the Ministry of Agriculture, Forestry and
Fisheries, Japan, 2006).
In some contaminated areas of Japan, Cd con-
centration of rice of 0.1-4.2 mg Cd/kg have been
reported (Tsuchiya, 1978). In contaminated areas
in China, average concentrations of approximately
1.0-3.7 mg Cd/kg have been found in rice (Jin
et al
.,
2002; Nordberg
et al
., 1997). Cui
et al
. (2004) reported
high levels of Cd in vegetables sampled in 2002 in an
area near Nanning, Guangxi Province, China, where
cultivation of rice had been terminated because of
contamination. In these countries, and in the UK and
New Zealand, high concentrations in certain marine
products have also been found (Elinder, 1985a;
WHO/FAO, 2003).
A high intake in consumers of seafood and shell-
fi sh in New Zealand (Nordberg
et al
., 1986) has been
Asia
41%
America
16%
Europe
15%
Recycling and stockpile
25%
Australia
3%
Source: International Cadmium Association (2002).
metal from Canada, Australia, and Mexico (WHO/
IPCS, 1992). In China and India, the use of NiCd bat-
teries has increased recently.
4 ENVIRONMENTAL LEVELS AND
EXPOSURES
4.1 General Environment
4.1.1 Food and Daily Intake
Extremely wide ranges of Cd concentrations have
been reported in foodstuffs from various countries.
Different results from different investigators ana-
lyzing the same types of food in the same area can
be explained, in some cases, by the possibility of the
use of inadequate analytical methods. Although such
