Abstract:
To achieve self-sufficiency in food grain production, the HYV rice varieties are
widely produced in Bangladesh, particularly in the dry season, and this requires a
large volume of groundwater for irrigation. Groundwater of many areas of our
country is severely contaminated with arsenic. So, there is a possibility of arsenic
.accumulation in rice plants from arsenic contaminated irrigation water. Generally,
consumption of protein is not adequate for our people due to insufficient production
of major protein sources like fish, meat, milk, eggs, etc. and also due to economic
constraints. Any adverse effect on protein content in rice due to use of arsenic
contaminated irrigation water may, therefore, aggravate the malnutrition problem of
our people. Similarly any adverse effect on amylose content, which is about one forth
portion of rice grain by weight, would cause deficiencies in calorie supply. This study
aims at assessing the accumulation of arsenic in rice plants and its possible effect on
nutrient (protein and amylose) content of rice grains. Arsenic contents in different
parts of rice plants were tested using hydride generation Atomic Absorption
Spectrophotometry (Shimadzu, AA6800). For assessing nutrient contents (protein and
amylose), rice samples were tested at the Laboratory of Grain Quality and Nutrition
Division of Bangladesh Rice Research Institute (BRRI), Gazipur. Results from this
study show that arsenic accumulates in different parts of rice plants, though the
accumulation varies from variety to variety. Highest arsenic concentration was found
in root hair with a mean 16.7 mglkg and maximum 38.5 mglkg, and least in grain with
a mean 0.32 mglkg and maximum 1.1 mglkg. Mean arsenic concentrations in husk,
leaf and stem were found to be 1.06 mglkg, 3.98 mglkg and 3.32 mglkg, respectively.
Presence of arsenic in straw (leaf and stem) at moderately high concentration poses
risks for cattle and human health. Arsenic concentration in top soil samples of study
fields were found to be up to 12 mg/kg. From linear regression analysis only a
moderate correlation (R2 = 0.45) was found between arsenic in water and arsenic in
root hair. Measured nutrient contents were compared with the standard values. Test
results for protein content show rice grain contain less protein than standard values.
Similarly, for most samples, amylose content was found to be less than standard
value. More studies are needed to better understand these phenomena.
