Determination of Ra-226, Ra-228 and K-40 specific activities in samples of mineral fertilizers marketed in the city of Rio de Janeiro, Brazil

Fertilizer samples were collected in the city of Rio de Janeiro and were analyzed using HPGe detector. The specific activities of Ra-226 ranged from 1.48 Bq/kg to 597 Bq/kg, of Ra-228 from 2.66 Bq/kg to 832 Bq/kg and of K-40 from 16 Bq/kg to 13941 Bq/kg. The risk to human health was found to be negligible.