EVALUATION OF THE ENVIRONMENTAL RADIOACTIVITY AROUND DANGOTE CEMENT EXCAVATION SITE

ABSTRACT

The aim of this research work is to measure and analyse the environmental radioactivity around Dangote cement, excavation site. To obtain data that will serve as reference material for environment assessment. The method of radiation measurement employed in this work, was direct observation and measurement of radiation from the excavation site using the radiation detectors. These detectors were held one meter above the radioactive sources at various distances of the mining excavation site of Dangote Cement Factory, Gboko. Finally, the background count was taken 200 meters from the excavation site. Readings were taken from two points 300 meters away from each other named excavation point A and B and 3 sets of readings each was taken at each point of measurement for every two minutes The direct observation and measurement of radiation from the excavation site using the radiation detector was obtained at significant values and the difference between them were almost the same. At point A, from table 4.1 the result shows the various average dose rates at various time intervals, with an insignificant average dose of 0.0333±0.0133(mSv/yr). From table 4.2, it shows an insignificant level of average exposure of 0.176±0.015(mR/hr). From table 4.3, the average activity shows an insignificant average activity of 3.46±0.19(KBq). From table 4.4, shows the average dose at point B, with an insignificant average of 0.352±0.434(mSv/yr). From table 4.5, it shows the average exposure an insignificant total average of 0.2668±0.078(mR/hr). From table 4.6, it shows average activity with an insignificant total average of 3.06±0.300(KBq). Therefore, this indicates that the result from the radiation excavates obtained was insignificant at a significance level of 1mSv/yr as recommended by the ICRP. The level of activities carried out by the people around the site must be reduced, because continuous accumulation of radiation may still result to health hazard. It is therefore recommended that there should be occupational and public awareness on the presence of natural radiation especially of limestone mining and cement production in the environment and their possible health hazards, background radiation and proper health monitoring should also be part of environmental assessment for industrial and mining project

CHAPTER ONE

1.0     INTRODUCTION

1.1     BACKGROUND

Radioactivity is the process by which a nucleus of an unstable atom losses energy by emitting particle of ionizing radiation. It is spontaneous emission of ionizing radiation as a consequence of nuclear reaction, or directly from the breakdown of an unstable nucleus. Materials that spontaneously emit these kinds of radiation include energetic alpha particle, beta particle, and gamma rays, and such are considered as radioactive (Landsberg, 1988).

In our everyday endeavour, we encounter radiation in an increasing rate in different forms. Radioactivity is found to be very beneficial but on the other hand very harmful and dangerous to the human body and its environment. This therefore makes its a necessity for us to study radiation to know where it comes from, to know its different types, its energy, how useful it can be and when it can be said to be dangerous to the body (Rani et al., 2005).

In real life there are radiation sources all around us due to cosmic rays from outer space which bombard the earth, radioactive substances in the earth’s crest, emanation of radioactive gas from the earth, trace amount of radioactivity in the body, radioactive rocks among others. There is no big problem with this, since this natural background radiation has always been there biologically, life on earth has always been exposed to these low levels of radiation. Radiation is been encountered in other artificial sources like radiological health centres, mining companies, nuclear power station and even scientific radioactivity research centres. The problem is when people are exposed to large doses of radiation in extraordinary circumstances. Most medical exposure comes from the use of standard x-rays and CT scans to diagnose injuries and diseases in patients Drugs with radioactive material attached known as radiopharmaceuticals, also are used to diagnose some diseases. Personnel in these institutions must be protected because radiation absorbed by tissue causes damage and other forms of deformation. The effects of this damage is manifested in such biological malfunctions and deformities as genetic mutation, destruction of blood/bones, leukaemia, (blood poisoning) redness of skin and skin burn, blindness, sterility (especially in man), baldness, death, cataracts and tissue damage.

1.2     RESEARCH PROBLEM

Scientific assessment have considered plant, animals and other living organism as part of the environment in which radionuclide became dispersed, they were further seen as resources which, when contaminated may contribute to human radiation exposure since some plants and animals are element of food chain and represent pathways for the transfer of radionuclide to humans. Therefore, the need to determine the level of concentration of radioactive level of one environment arises so as to proffer possible solution in tackling the effect of radioactive concentration to humans and it ecosystem.

1.3     AIM AND OBJECTIVE

The aim of this research work is to measure and analyse the environmental radioactivity around Dangote cement, excavation site.

1.3.1  OBJECTIVE OF THE RESEARCH WORK

The following are the specific objectives of the research work.

    i.                     To statistically analyse the environmental radioactivity around Dangote cement the excavation site.

  ii.                     To determine whether the soil or environment is safe for human activities.

1. To obtain data that will serve as reference material for environment assessment
2. Generate base line for radiation monitoring.

1.4     SIGNIFICANT OF STUDY

Since radionuclide’s are found naturally in air, water and soil, they are even found in human beings, that we are product of our environment, every day we take in radionuclide in air, food and water. When the human body is exposed to radiation closes above the normal permissible dosage equivalence as recommended by ICRP, it causes health hazards if the radioactivity level is above normal or approaching danger zone it will be necessary for the environmental protection department to ban all activities at least in the specific areas under research as defined by the scope. This will save lives that might have fallen victims of severe radioactive hazards, therefore making this investigation very important for various element and concrete removals/extractors among many others.

1.5     SCOPE AND LIMITATIONS OF THE STUDY

The research work is carried out in Dangote cement, which is the excavation site in Benue State of Nigeria around Tse-kucha, Gboko Local Government area within the middle Benue trough.

1.5.1  LIMITATION

In the measurement of environmental radioactivity around Dangote cement, inadequate supply and lack of useful materials in the site/field can hinder the progress of this work.

1.6     DESCRIPTION OF THE STUDY AREA

The study area is located in Tse-kucha quarry of Dangote Cement Company limited Gboko in Benue state of Nigeria. The area falls within the middle Benue Trough, where the albiann sediments of the Asu river group are exposed. It lies within longitudes 8056' and 9000'E and latitudes 7020' and 7030', part of Gboko sheet 271. For many years, several authors have been working on the cretaceous sediments of the Benue Trough. The trough is geographically divided into three portions, lower, middle and upper Benue trough, the trough generally consist of both continental elastic deposits and marine sediments. The origin/evolution and stratigraphy of the trough have been discussed in details by Burke et al. (1970), Grant (1971), Nwachukwu (1972) and others.