Estimating ambient gamma dose rate in the oil town of Pacayacu, Ecuador

Authors

  • GILSON PUCHA ESPOCH https://orcid.org/0000-0002-8679-327X
  • Víctor Armijos Grupo de Energías Alternativas y Ambiente, Escuela Superior Politécnica de Chimborazo, EC060155, Riobamba, Chimborazo, Ecuador https://orcid.org/0009-0004-7836-1663
  • Bolívar Flores Escuela Superior Politécnica de Chimborazo
  • Celso Recalde Grupo de Energías Alternativas y Ambiente, Escuela Superior Politécnica de Chimborazo, EC060155, Riobamba, Chimborazo, Ecuador

DOI:

https://doi.org/10.15392/2319-0612.2025.2818

Keywords:

Ambient gamma dose equivalent rate, Oil industry, NORM and TENORM, Waste management, Ionizing radiation

Abstract

This study estimated the ambient equivalent dose rate in the oil parish of Pacayacu, which is located in Lago Agrio, Sucumbíos province. It has experienced constant oil activity since 1980. Measurements were performed in 77 different places, including 63 closed oil wells, eight points near operating wells, three points between Pacayacu and the Aguarico River, one mining concession, and two control points. Ludlum digital meters connected to NaI(Tl) scintillation probes were used to obtain five one-minute measurements at each site. The average ambient equivalent dose rate was 0.12 µSv·hˉ¹, with values ranging from 0.05 to 0.20 µSv·hˉ¹, excluding the highest value of 0.86 µSv·hˉ¹ at one site. The annual effective dose of the external irradiation was calculated using the average ambient equivalent dose rate at each sampling point. One closed well coded "PPC(SHR-04)" had an annual effective dose of 1.51 mSv·yˉ¹, that exceeded the public exposure limit established by national law (0.3 mSv·yˉ¹) and the 1 mSv·yˉ¹ limit defined by the IAEA. Sweeping measurements around this well indicated that the elevated gamma radiation originated from pipes delimiting the well, point to the presence of NORM internal scales. Consequently, these results highlight the potential influence of oil activity on the annual effective dose. In oil areas, the focus should be on the importance of proper waste management to prevent exposure to NORM, avoid internal contamination and environmental pollution.

 

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Author Biographies

  • GILSON PUCHA, ESPOCH

    Grupo de Energías Alternativas y Ambiente

    Research Technician

  • Víctor Armijos, Grupo de Energías Alternativas y Ambiente, Escuela Superior Politécnica de Chimborazo, EC060155, Riobamba, Chimborazo, Ecuador

    Grupo de Energías Alternativas y Ambiente

    External Research Technician

  • Bolívar Flores, Escuela Superior Politécnica de Chimborazo

    Escuela Superior Politécnica de Chimborazo 

    Teacher

  • Celso Recalde , Grupo de Energías Alternativas y Ambiente, Escuela Superior Politécnica de Chimborazo, EC060155, Riobamba, Chimborazo, Ecuador

    Grupo de Energías Alternativas y Ambiente

    Director 

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Published

2025-05-23

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How to Cite

Estimating ambient gamma dose rate in the oil town of Pacayacu, Ecuador. Brazilian Journal of Radiation Sciences, Rio de Janeiro, Brazil, v. 13, n. 2, p. e2818, 2025. DOI: 10.15392/2319-0612.2025.2818. Disponível em: https://www.bjrs.org.br/revista/index.php/REVISTA/article/view/2818. Acesso em: 24 may. 2025.