TITLE:
Bioavailability of Chlorpyrifos in Wheat Plants (Triticum aestivun)
AUTHORS:
Sylvia V. Copaja, Rosa Vergara, Héctor R. Bravo
KEYWORDS:
Soil, Chlorpyrifos, Wheat, Persistence, Bioavailability
JOURNAL NAME:
Agricultural Sciences,
Vol.5 No.8,
July
8,
2014
ABSTRACT: Adsorption
processes of chlorpyrifos in two Chilean agro soils (Calera: C; San Esteban:
SE) in relation with the bioaccumulation in wheat plants (Triticum aestivun) were studied. RP-HPLC method was developed to
determine the chlorpyrifos content in soils, roots and seedling tissues. The
two soils showed high adsorption capacity (C = 78%, SE = 92%). The values are
not in relation with the contents of organic matter (C = 3.9% and SE = 2.0%)
and clay (C = 12.7% and SE = 10.1%) determined in the soils. Persistence and
mobility of chlorpyrifos in the soils were estimated from halflife values (Csoil
= 23 d, SEsoil = 14 d) and the Guss index (Csoil = 0.89,
SEsoil = 0.25) respectively. These values are in the range of
non-leaching compounds, and suggest that there should be no pollutant in the
ground water. Wheat plants grown in both soils incubated with chlorpyrifos bioaccumulate
residues in roots and seedling tissues. Root tissues showed the greatest
contents (C = 22.3 mg/k. f. wt; SE = 51.8 mg/kg. f. wt.). Germination and
growth of wheat young plants were not inhibited for the contents in the
tissues. A relation between the levels of chlorpyrifos residues in the soils
and the bioaccumulation in wheat tissues was estimated from the BAI parameter.
Values showed that the bioaccumulation is dependent on the residues contents in
soils. These results suggest that bioavailability of chlorpyrifos in wheat
plants may be a harmful pollutant for mammals if it remains stable at all
growth stage of the plant. Further research should be considered to see if
bioavailability in forage and/or grain can occur.