Arsenic (As) is a toxic metalloid for plants and animals.
Large amounts of As have been released in arable soils
through anthropogenic activities, use of contaminated
irrigation water, and mining among others. Rice (
Oryza sativa
L.) is one of the most consumed cereals worldwide;
it is an important route of exposure for As. The objective of
this review was to explain possible mechanisms involved
in As absorption that contaminate rice plant through the
soil and water, and to mention studies that have been
conducted to minimize the risk of human exposure. The
root is able to absorb and accumulate large amounts of As,
but only small amounts are translocated to the grain and
tillers. Arsenic concentrations in rice tissues decrease from
the root to the grain. Information about As translocation
in rice is sparse and research is directed toward studying
the molecular mechanism of absorption and accumulation
in the grain because it has not yet been explained. Some
rice varieties have been developed that are resistant to high
soil As concentrations and are not able to translocate the
metalloid toward the root. Many studies suggest that not all
ingested inorganic As accumulated in the gastrointestinal
tract is absorbed into the bloodstream and produces toxicity.
It is therefore recommended that As bioavailability be
evaluated in imported or domestic Chilean rice to more
precisely estimate human health risk.
