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Trace Elements in Abiotic and Biotic Environments
microorganisms. Under reducing soil conditions, a stepwise change from Te 6+ to Te 2–
occurs. All species of Te may be adsorbed by both Fe and Mn hydroxides.
48.3 WATERS AND AIR
Tellurium concentrations in surface waters range from 0.17 to 0.9 ng/L, being highest in the Red Sea (Kobayashi 2004). In the North Pacific, it averages 0.05  ng/L
(Nozaki 2005).
Rainwater sampled in 1984 in Florida contained Te within the range of 0.51–3.3 ng/L
(Andrea vide Kobayashi 2004). The concentration of Te in rainwater of Sweden, in
1999, varied from 0.1 to 1.1 ng/L, at an average value of 0.4 ng/L. Its wet deposit was
calculated as 22 mg/ha/yr (Eriksson 2001a).
The median Te concentrations in bottled waters of the EU countries is 7.98 ng/L,
and it is slightly lower (9.98 ng/L) than in tap waters (Birke et al. 2010).
Tellurium in air averages 0.12 ng/m 3 in Japan, within the range of 0.35–50 ng/m 3
(Kobayashi 2004). Its concentrations of 0.78 and 0.24 ng/m 3 are reported to be in
interior and exterior air samples in Au mining areas (Nozaki 2005).
48.4 PLANTS
Tellurium has no biological function, although fungi can incorporate it, in place of S
and Se, into some amino acids. Plants uptake Te relatively easily and correlate positively with its contents in growth media. Seleniferous plant species (e.g., Astragalus)
contain elevated Te amounts, up to about 6 mg/kg, especially when grown in areas
of Cu mining. Several plants from mining and industrial regions, mainly of Cu, may
contain Te up to 25 mg/kg (Cowgill vide Kabata-Pendias 2011).
Generally, Te contents of plants do not exceed 1 mg/kg. Vegetables contain Te
within the range of <0.013 mg/kg fresh weight (FW) in apple fruits to >0.35 mg/kg
FW in onion. The garlic odor is caused by vapors of dimethyl telluride [(CH 3 ) 2 Te].
Barley and wheat grains from Sweden contain Te at the mean value of <0.001 mg/kg
(Eriksson 2001a). Norwegian mosses sampled in the period 1990–1995 contained Te
within the range of <0.002–0.089 mg/kg, at an average value of 0.005 mg/kg (Berg
and Steinnes 1997).
48.5 HUMANS
Tellurium content in humans (70 kg) is estimated to be 0.7 mg (Emsley 2011). About
10%–20% of ingested Te appears to be absorbed by the body (Reilly 2002).
Animal studies suggest that up to 25% of orally administered Te is absorbed in
the gut. It is also found in the heart, kidney, spleen, bone, and lung. Formation of
dimethyl telluride [(CH 3 ) 2 Te] is a characteristic feature of exposure and gives a pungent garlic-like odor to breath, excreta, and viscera. The main target sites for Te toxicity are the kidney, nervous system, skin, and fetus (hydrocephalus) (Taylor 1996).
The toxic effects associated with specific Te compounds depend on its chemical
forms, such as inorganic and/or organic compounds, and often also on the oxidation state. Organotellurium compounds, with reasonably stable Te–carbon bonds,