Analisis Risiko Radiologis dari Pasir Besi terhadap Manusia dan Biota Non-Manusia di Laguna Pengklik

RAFI FADLURRAHMAN, Ir. Anung Muharini, M.T., IPM.; Ir. Gede Sutresna Wijaya, M.Eng.

2025 | Skripsi | TEKNIK NUKLIR

Laguna Pengklik, yang terletak di pesisir selatan Yogyakarta, memiliki potensi risiko radiologis karena transportasi sedimen pasir besi dari Gunung Merapi menuju laguna. Pasir besi mengandung radionuklida alami seperti 226Ra, 232Th, dan 40K, yang memancarkan radiasi terhadap manusia dan biota non-manusia di sekitarnya. Penelitian ini bertujuan untuk mengukur aktivitas jenis radionuklida pada pasir besi serta mengevaluasi risiko radiologis yang ditimbulkan.

Spektroskopi gamma berupa detektor HPGe model GEM-30185 serial No. 34-P11063A digunakan untuk mengidentifikasi jenis radionuklida dan aktivitas jenis pada sampel pasir besi, yang kemudian digunakan untuk menghitung potensi bahaya radiologis untuk manusia dan biota non-manusia. 

Hasil penelitian menunjukkan aktivitas jenis 226Ra berkisar antara (27,27±2,93) Bq/kg hingga (49,07±3,81) Bq/kg, 232Th antara (23,48±3,51) Bq/kg hingga (41,67±4,65) Bq/kg, dan 40K antara (593,12±76,58) Bq/kg hingga (1230,22±100,08) Bq/kg. Nilai rerata aktivitas jenis ketiga radionuklida tersebut melebihi rerata global UNSCEAR. Risiko radiologis terhadap manusia berdasarkan parameter radiologi, seperti Raeq sebesar (150,13±8,60) Bq/kg, Hex (0,41±0,02), Hin (0,50±0,03), I? (1,15±0,07), AED (0,09±0,005) mSv/tahun, dan ELCR (0,31±0,02)×10-3. Seluruh parameter berada di bawah nilai UNSCEAR kecuali I? dan ELCR. Analisis terhadap biota non-manusia menggunakan ERICA Tool menunjukkan laju dosis di antara 0,0363 ?Gy/jam hingga 0,2810 ?Gy/jam. Laju dosis terkecil diterima zooplankton dan laju dosis terbesar diterima serangga. Seluruh laju dosis berada di bawah batas aman IAEA, US-DOE, dan UNSCEAR.

Pengklik Lagoon, located on the southern coast of Yogyakarta, presents a potential radiological risk due to the transport of iron sand sediments from Mount Merapi to the lagoon. Iron sand contains natural radionuclides such as 226Ra, 232Th, and 40K, which may affect humans and non-human biota in the surrounding area. This study aims to measure the radionuclide activity in the iron sand and evaluate the resulting radiological risk.

Gamma spectroscopy with an HPGe detector model GEM-30185 serial No. 34-P11063A was used to identify the types of radionuclides and their activity in the iron sand samples, which were then used to calculate the radiological hazard potential on human and non-human biota.

The results of the study showed that the 226Ra activity ranged from (27.27±2.93) Bq/kg to (49,07±3.81) Bq/kg, 232Th from (23.48±3.51) Bq/kg to (41.67±4.65) Bq/kg, and 40K from (593.12±76.58) Bq/kg to (1230.22±100.08) Bq/kg. The mean activity of these three radionuclides exceeded the global average reported by UNSCEAR. The radiological risk to humans based on radiological parameters, such as Raeq of (150.13±8.60) Bq/kg, Hex (0.41±0.02), Hin (0.50±0.03), I? (1.15±0.07), AED (0.09±0.005) mSv/tahun, dan ELCR (0.31±0.02)×10-3, was within the recommended value by UNSCEAR except for I? and ELCR. Analysis of non-human biota using the ERICA Tool showed dose rates in range of 0.0363 ?Gy/hour to 0.2810 ?Gy/hour. The smallest dose rate was received by zooplankton and the largest dose rate was received by insects, all of which were below the safe limits established by IAEA, US-DOE, and UNSCEAR.

Kata Kunci : pasir besi, risiko radiologis, laguna pengklik, ERICA Tool