Sources of Radon and its Measurement Techniques in Underground Uranium Mines – An Overview

Purpose: This study aims to identify the potential sources of radon exhalation and its measurement in underground uranium mines to control the radiation levels within safe limits and protect miners from radiation hazards. Methods: An extensive literature review on radon exhalation in underground uranium mines from various sources such as uranium ore, backfill tailings and mine water has been carried out. The influence of different important factors, viz. ore grade, porosity, grain size and moisture content on radon exhalation has been discussed in depth. Different methods for the measurement of radon exhalation from various sources in mines have also been presented in this paper. Results: The review of literature revealed that the radon exhalation rate in porous uranium bearing rocks is less affected by the ore grade than in non-porous rocks. The exhalation of radon from backfill tailings is quantitatively more significant than from the uranium ore itself due to higher bulk porosity and enhanced surface area. Thus, porosity is the dominant factor that affects the rate of radon exhalation from rock surfaces into mine openings. Practical implications: The knowledge of the sources of radon and quantitative estimation of radon from various sources will be very much useful in the planning and designing of ventilation systems in underground uranium mines. The accurate measurement of radon exhalation in underground uranium mines can be made by choosing the optimum size of accumulation chamber and a suitable radon build-up period in the chamber. Originality/value: The study portrays the important sources of radon and its measurement techniques in underground uranium mines based on an extensive literature review. The methods of measurement of radon exhalation from the ore body and backfill tailings in underground uranium mines, used by the authors of this paper, comparatively give more accurate results than previously used methods. Furthermore, the methods are more effective in terms of portability, cost and time for measuring the average radon exhalation across a large

Evaluation of Donor Ankle Stability, Function and Body Balance Following Anterior Cruciate Ligament Reconstruction with Peroneus Longus Tendon Graft -A Prospective Cohort Study

Background: The effect of harvesting peroneus longus tendon graft (PLTG) for anterior Cruciate ligament reconstruction (ACLR) on donor ankle stability and function and its effect on overall body balance is not yet investigated. PLT is thought to play some role in the proprioceptive regulation of the ankle joint. ACL too has a vital role in the postural control of the knee joint. This study evaluates and compares the affected and sound limb balance and function in subjects following ACLR with autologous PLTG. Methods: A total of 44 eligible participants were assessed for balance using the HUMAC balance system and function with the Foot Ankle Ability Measure (FAAM) scale at 6week, 3month, and 6month after ACLR with PLTG. Outcome measures were stability score, path length, average velocity, time on target, and FAAM score. Results: There was statistically significant improvement in all the parameters of bilateral or unilateral standing balance at 6month post-op [Bilateral: stability score: p=0.001; path length: p=0.000; average velocity: p=0.000; time on target: p=0.006]; [unilateral-affected/sound: path length: p=0.000, p=0.003; average velocity: p=0.000, p=0.009). The difference between affected and sound limb balance was insignificant. Median of FAAM score at 6week, 3month, & 6month were 97.368, 98.809 and 100 respectively. Conclusion: Balance of the whole body or any single leg stability is impaired after ACLR with PLTG, but it may improve to an optimal level with due time and recover fully by six months. Donor ankle function also restores to 100% at 6month