posted on 2016-02-20, 15:21authored byAntonino Spanu, Leonardo Daga, Anna Maria Orlandoni, Gavino Sanna
The bioaccumulation of arsenic compounds in rice is of
great concern
worldwide because rice is the staple food for billions of people and
arsenic is one of the most toxic and carcinogenic elements at even
trace amounts. The uptake of arsenic compounds in rice comes mainly
from its interaction with system soil/water in the reducing conditions
typical of paddy fields and is influenced by the irrigation used.
We demonstrate that the use of sprinkler irrigation produces rice
kernels with a concentration of total arsenic about fifty times lower
when compared to rice grown under continuous flooding irrigation.
The average total amount of arsenic, measured by a fully validated
ICP-MS method, in 37 rice grain genotypes grown with sprinkler irrigation
was 2.8 ± 2.5 μg kg–1, whereas the average
amount measured in the same genotypes grown under identical conditions,
but using continuous flooding irrigation was 163 ± 23 μg
kg–1. In addition, we find that the average concentration
of total arsenic in rice grains cultivated under sprinkler irrigation
is close to the total arsenic concentration found in irrigation waters.
Our results suggest that, in our experimental conditions, the natural
bioaccumulation of this element in rice grains may be completely circumvented
by adopting an appropriate irrigation technique.