Concentration of 40K, 226Ra, 228Ra and 228Th in the main brands of pet food sold in Brazil.

Abstract

Pets are constantly exposed to natural radionuclides through their diet, yet studies on the radiological evaluation of animal food remain scarce, especially in Brazil, one of the leading markets in the pet industry. This research estimated the specific activity concentrations of the natural radionuclides 226Ra, 228Ra, 228Th and 40K in representative samples of dog, cat, bird and rabbit food from the most sold brands in Brazil. Measurements were performed by gamma spectrometry using an HPGe detector. The average specific activity concentration of 40K in dog, cat, bird and rabbit food resulted in 235 ± 14, 252 ± 15, 349 ± 22 and 567 ± 31 Bq kg-1 dw, respectively. For 226Ra, 228Ra and 228Th the reported ranges (Bq kg-1 dw) were approximately 0.7-12.4. The effective dose coefficients due to 40K ingestion for dogs, cats, birds and rabbits were 8.5 x 10-14, 9.0 x 10-13, 4.9 x 10-12 and 1.0 x 10-12 Sv Bq-1, respectively. The external risk index due to gamma radiation for humans handling the food was below the limit of 0.3 mSv year-1 used for restriction in biota, indicating no significant radiological risk to animals or humans. Therefore, the consumption of this commercial food is considered radiologically safe for pets, while the established reference values are important for monitoring and identifying possible radionuclide contamination in food for these animals.