Níveis de risco radiológico de rochas de construção escavadas em pedreiras no condado de Kericho, no Quênia
DOI:
https://doi.org/10.5935/jetia.v8i37.834Resumo
O estudo determinou os níveis de concentração de atividade natural de 40K, 232Th e 238U em rochas usadas para construção das 15 pedreiras selecionadas no condado de Kericho, no Quênia, por meio de análise espectrométrica de raios gama no departamento de Ciências Físicas da South Eastern Kenya University (SEKU). Os procedimentos da AIEA foram seguidos desde a coleta, preparação e medição das amostras. As amostras foram coletadas, trituradas, secas em estufa a 105ºC, pesadas e acondicionadas em recipientes lacrados e mantidas por quatro semanas para que o equilíbrio secular fosse alcançado entre 226Ra e 232Th. A concentração média de atividade de 232Th, 238U e 40K foi de 101 ± 5 Bq/kg, 56 ± 3 Bq/kg e 1100 ± 55 Bq/kg e variou de 41 ± 2 a 138 ± 7 Bq/kg, 26 ± 1 a 116 ± 6 Bq/kg e 512 ± 26 a 1919 Bq/kg ± 96 Bq/kg, respectivamente. Os índices médios de risco externo e interno foram de 0,8 mSv/ye 0,9 mSv/y, respectivamente. O equivalente de rádio variou de 222 ± 11 Bq/kg a 366 ± 18 Bq/kg com um valor médio de 285 ± 14 Bq/kg que estava abaixo do limite permitido de 370 Bq/kg; portanto, as rochas escavadas para construção nas pedreiras selecionadas no condado de Kericho representam um risco insignificante para a saúde da população em geral e dos trabalhadores da pedreira.
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