Cosmic-ray exposure assessment using particle and heavy ion transport code system: case study Douala-Cameroon

Area of Science:

• Environmental Science
• Radiation Physics
• Public Health

Background:

• Cosmic radiation is a significant environmental factor contributing to public radiation dose.
• Understanding location-specific cosmic ray exposure is crucial for accurate public health risk assessments.

Purpose of the Study:

• To simulate and determine cosmic ray fluxes and effective doses for the population of Douala.
• To compare simulated doses with established global values from UNSCEAR.

Main Methods:

• Utilized the Particle and Heavy Ion Transport code System (PHITS), a Monte Carlo code, for detailed simulations.
• Calculated effective dose contributions from various cosmic ray components (neutron, muon, electron, positron, photon).

Main Results:

• The total effective dose at ground level in Douala was found to be 0.31 ± 0.02 mSv/y during minimum solar activity and 0.27 ± 0.02 mSv/y during maximum solar activity.
• Muons+ were identified as the main contributors to the effective dose (~38%), while electrons and positrons contributed the least.
• Simulated doses were lower than UNSCEAR estimates, attributed to equatorial magnetic field deflection.

Conclusions:

• The population of Douala experiences a non-significant exposure to cosmic radiation.
• The study provides a localized dose assessment, highlighting the influence of geographical location on cosmic ray exposure.