Restoring areas after a radioactive fallout: A multidisciplinary study on decontamination.

Area of Science:

• Environmental Science
• Radiological Protection
• Social Science

Background:

• Land remediation is vital after radioactive fallout, especially from long-lived isotopes like cesium-137 (¹³⁷Cs).
• Urban areas present unique challenges for decontamination and resident safety.
• Understanding the effectiveness, costs, and public perception of remediation is essential for effective disaster planning.

Purpose of the Study:

• To assess the impact of decontamination timing on reducing resident radiation exposure.
• To calculate the direct and indirect costs associated with decontaminating urban areas in Sweden.
• To investigate Swedish citizens' willingness to return to decontaminated sites and inform contingency plans.

Main Methods:

• Multidisciplinary analysis integrating radiological, economic, and social survey data.
• Modeling of radiation dose reduction based on decontamination timelines.
• Cost-benefit analysis of cleanup operations and waste generation.
• Survey of 2291 Swedish residents regarding hypothetical resettlement post-fallout.

Main Results:

• Decontamination is most effective within the first few years post-fallout, averting significant radiation doses (20-200 manSv/km² per MBq/km^{2 137}Cs).
• Direct decontamination costs are substantial (approx. €100 million/km²), generating significant radioactive waste (39,000 m³/km²).
• Public skepticism towards returning to decontaminated areas was higher among women, families with children, and high-income earners, mirroring Fukushima evacuee patterns.

Conclusions:

• Early post-accident planning, guided by ¹³⁷Cs deposition levels, is critical for effective remediation, evacuation, and risk communication.
• Addressing public risk perception and aversion is vital, as communication alone may not prevent demographic shifts in affected areas.
• Fairness, particularly regarding monetary compensation for residents, must be prioritized to ensure successful resettlement and avoid inefficient decontamination spending.