Abstract 

Within and around major towns in Edo North, Edo State, Nigeria, there are scores of quarry industries whose activities constitute menace in the immediate 

environment. This study therefore assessed the level of natural background gamma radiation within a typical quarry sites located at Igarra the Headquarters 

of Akoko Edo Local Government Area, Edo State Nigeria. Measurement of background gamma radiation around the quarry site was carried out with Digital 

Geiger Counter GCA-07 model, calibrated with Cesium-137 (
 ) with a confidence interval of ±5% alongside with a calibrated digilert-50 nuclear 

radiation monitor. Measurements were made three times (morning, afternoon and evening) daily. 

Simultaneously, the ambient temperature and humidity were measured by means of an electronic thermo-hygrometer, model THC-20 manufactured by Shenzhen Tonglixing, China. 

The results obtained show that the background gammaradiation ranged from a minimum of 12.50 cpm to a maximum of 18.00 cpm for GCA-07and from 

a minimum of 11.10 cpm to a maximum of 16.20 cpm for Digilert-50. The ambient temperature and humidity values were found  to range from a minimum 

of 25.14°C to a maximum of 31.30°C and from a minimum of 52.7% to a maximum of 77.30% respectively. The mean radiation dose varying from 0.456 to 0.885 mSv/yr and 0.394 to 0.788mSv/yr for Digital Geiger Counter GCA-07 and Digilert-50 nuclear radiation monitor were comparedwith standard radiation dose limits of a body. The radiation dose values were found to be lower than the dose limit of 1mSv/yr in a normal background radiation environment according to the guidelines set out by the International Commission on Radiological 

Protection (ICRP) for all persons, other than thoseoccupationally exposed. 

However, continuous exposure on the parts of the quarry workers and the farmers in the study area may constitute health hazards in the near future. Thus, 

regular monitoring of radiation level and determination of different types of radio-nuclides in the area is recommended in order  to put in place appropriate measures and mechanisms that will serve as a check on the health and safety of 

the people. 

Keywords:Background radiation, ambient temperature, count per minute, dose limit