A possible method for estimating the true absorption coefficient for radiocaesium in ruminants

Area of Science:

• Environmental Science
• Radiological Science
• Animal Science

Background:

• Radiocaesium contamination from sources like Chernobyl poses risks.
• Accurate estimation of radiocaesium absorption in livestock is crucial for food safety.
• Previous methods may not fully account for endogenous fecal excretion.

Purpose of the Study:

• To develop and validate a method for estimating the true absorption coefficient of radiocaesium (137Cs) in sheep.
• To assess the impact of variations in fecal to urinary 137Cs excretion ratios on absorption coefficient estimates.
• To differentiate radiocaesium absorption from different contamination sources.

Main Methods:

• Estimating the ratio of 137Cs excretion in feces versus urine in sheep previously exposed to contaminated pastures.
• Utilizing urinary excretion rates to determine endogenous fecal 137Cs.
• Calculating the true absorption coefficient using excretion data from diets with radiocaesium from Chernobyl and Sellafield effluent.

Main Results:

• A two-fold range in the fecal to urinary 137Cs excretion ratio was observed in housed ewes and lambs.
• The developed method allowed for the estimation of endogenous fecal 137Cs.
• Variations in the fecal:urine excretion ratio demonstrated a minimal effect on the calculated true absorption coefficient.

Conclusions:

• The described method provides a reliable way to determine the true absorption coefficient for radiocaesium in sheep.
• The findings indicate that the fecal:urine excretion ratio, while variable, does not significantly compromise the accuracy of absorption coefficient estimations.
• This method aids in assessing the internal contamination and absorption dynamics of radiocaesium in livestock.