Environmental Footprint of Oil Extraction: Insights from Elemental and Radiological Analysis of Well Cuttings from Three Oilfields in Pakistan

Oil and gas exploration is a cornerstone of the global energy sector, yet the environmental and radiological impacts of drilling activities in Pakistan remain poorly characterized. This study evaluated elemental and radionuclide contamination in drill cuttings from three Pakistani oilfields Jand, Dhulian, and Neshpa using Instrumental Neutron Activation Analysis (INAA) and gamma spectrometry with a high-purity germanium (HPGe) detector. Drill cuttings from six sampling sites across three oilfields were analyzed. INAA was used to quantify elemental compositions, while gamma spectrometry with an HPGe detector was employed to determine natural radionuclide activity concentrations. Health risk parameters for radionuclide exposure calculated following UNSCEAR guidelines. Elemental analysis revealed distinct geochemical signatures across sites. Jand oilfield samples showed elevated Al (up to 51,480 mg kg⁻¹), Fe (up to 72,235 mg kg⁻¹), As (21 mg kg⁻¹), Ba (up to 1,690 mg kg⁻¹), and rare earth elements (Ce up to 112 mg kg⁻¹). The Dhulian sample (DOFS1) was characterized by exceptionally high Mn (2,832 mg kg⁻¹), Fe (23,668 mg kg⁻¹) and Al (62999 mg kg −1 ), while Neshpa samples exhibited elevated Mg (8,411 mg kg⁻¹), K (21,496 mg kg⁻¹), Ba (1,686 mg kg⁻¹), and Cr (127 mg kg⁻¹). Radiological analysis identified K-40 as the dominant radionuclide (457–1,298 Bq kg⁻¹, mean: 947 Bq kg⁻¹), approximately 2.4-fold above the global average of 400 Bq kg⁻¹, reflecting natural K-bearing mineralogy rather than anthropogenic contamination. The Ra-226 (Mean: 28.61 Bq kg⁻¹) and Th-232 (Mean: 35.5 Bq kg⁻¹) activities exceeded the threshold limit (25 Bq kg⁻¹). Outdoor effective doses (0.068 mSv y⁻¹) is below the 0.07 mSv y⁻¹ public exposure limit, whereas indoor effective doses (0.32–0.64 mSv y⁻¹, mean: 0.53 mSv y⁻¹) exceeded the UNSCEAR reference level of 0.41 mSv y⁻¹. Indoor ELCR values (1.13×10⁻³–2.24×10⁻³, mean: 1.85×10⁻³) surpassed the global benchmark of 1.16×10⁻³. These findings establish a geochemical and radiological baseline for Pakistani oilfields and highlight occupational health concerns for workers in enclosed environments. Implementation of health monitoring programs, exposure time controls, and enhanced ventilation in enclosed work areas is strongly recommended to ensure worker safety during oil exploration activities.