Are fluorite mines prone to high concentrations of radon gas inside? The case of the Lújar mine in Órgiva (Granada, Southeast Spain)

Abstract

The Sierra de Lújar, located in the south of Granada (Spain), hosts one of the few currently active underground fluorite mines in Spain. Considering that high concentrations of radon gas, which is the second leading cause of lung cancer after tobacco, can occur in underground workplaces, the concentration of radon gas inside a fluorite underground mine has been measured, in order to prevent health risks to workers. QueryAlthough no significant concentration of radioactive elements has been detected in the geochemical analysis, the radon gas concentration values measured ranged between 28 and 1211 Bq m−3, and there were important variations, depending on the area of the mine. Some values exceed the limits established by European regulations. Despite these high values, the annual effective dose (E) ranges between 0.13 and 5.71 mSv, in most cases being below 3 mSv, which is the recommended value in underground mines. Improvement in the ventilation of main galleries, especially in the benefit plan area (level 423), the isolation of mined-out areas using bulkhead, continuous monitoring of radon concentration, and periodic health controls to workers are estimated as the main mitigation measures to take into consideration. The findings from this research suggest that workers in this underground fluorite mine may face substantial risk of receiving radon doses that could meet or surpass the recommended thresholds established by European regulations. This underscores the imperative for additional investigations into radon levels within underground operations in Spain.