Published in:Zbornik Matice srpske za prirodne nauke
Language:
English
DOI:
10.2298/zmspn2344051k
ISSN:
0352-4906;
2406-0828
Origination:
Footnote:
Description:
<jats:p>Rare earth elements (REEs) are widely distributed in low concentrations in
all parts of the biosphere. REEs are not at all rare, their concentration in
the earth?s crust is close to 0.015%. REEs include the elements scandium,
yttrium and the lanthanides from lanthanum to lutetium. REEs show similar
physical and chemical properties. Today REEs are applied in industries and
technologies, in agriculture as microfertilizers and feed additives and they
are also used in medicine. REEs are dispersed especially as accessory
minerals in pegmatites, granites and associated metamorphic volcanic rocks.
Out of more than 250 kinds of minerals containing REEs, only bastnaesite and
monazite are of economic importance. Their concentration in the soil varies
widely and depends on their presence in parental materials, soil texture,
organic matter content, pedogenetic processes and anthropogenic activities.
REEs are found in small concentrations in surface stagnant and flowing
waters as well as in underground waters. They are found in water in both
suspended and dissolved form. REEs enter the atmosphere from various
sources, largely owing to human activities. The majority of REEs in the
atmosphere are carried by microscopic particles. The uptake and consequently
accumulation of REEs in plants are affected by numerous biotic factors, such
as plant species and genotype, and abiotic factors such as their
concentration in the soil and some chemical and physical soil
characteristics. They can enter plants via both root and foliage tissues.
There are plant species called hyperaccumulators that are able to accumulate
significant amounts of REEs without adverse consequences. RREs are not
biogenic for higher plants or for other living organisms, but can influence
their life processes. Experi?ments show that REEs can be beneficial for
growth, yield and biochemical composition of cultivated plants. They can
also alleviate some ecological stress in plants. It is not clear enough how
they affect human and animal health. The wide-spread application of REEs in
different industries as well as in agriculture lead to a constant increase
of the concentrations of these elements in the environment. Therefore,
studies on the uptake, accumulation, dis?tribution of REEs in cultivated
plant species and their entrance into the food chain as well as their
stimulating or toxic effect on living organisms, can be very significant in
the future.</jats:p>