In this work, the specific activities of natural radionuclides, namely ²³⁸U series, ²³²Th series and ⁴⁰K, have been measured in collected sedimentary phosphate deposits samples from El-Hamraween, El-Quser and Safaga phosphate mines in Egypt. HPGe γ-spectrometry was used. This study was undertaken to estimate the radiation hazard indices in phosphate mining at the studied mines on their occupational workers, to establish correlation relationships between the some measured heavy metals such as As, Cd and Pb in blood workers and their concentration in phosphate rock ores and to determinate the biomarkers in the blood workers such as malondialdehyde (MDA) and superoxide dismutase (SOD). The phosphate mine sample of El-Hamrawein has the lowest activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K in comparison to the phosphate mine samples of El-Quseir and Safaga (El-Hamrawein < El-Quseir < Safaga). The activity concentrations for the radionuclide’s considerably were fluctuated; for ²²⁶Ra activity concentrations varied from 222.4 to 255.8 Bq·kg^-1, 122.4 to 188.3 Bq·kg^-1 and 115.4 to 165.8 Bq·kg^-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For ²³²Th activity concentrations varied from 135.6 to 212.3 Bq·kg^-1, 112.8 to 167.4 Bq·kg^-1 and 132.8 to 188.6 Bq·kg^-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For ⁴⁰K activity concentrations varied from 225.2 to 312.8 Bq·kg^-1, 168.7 to 268.9 Bq·kg^-1 and 95.2 to 155.8 Bq·kg^-1 for Safaga, El-Quseir and El-Hamrawein, respectively. The workers of old ages have higher concentration of the investigated heavy metals than those of young ages. There is a good relation between the concentration of the investigated metals in phosphate mine samples and their concentration in blood of the occupational workers in these mines.