Measurement And Assessment Of Indoor And Outdoor Ambient Radiation Levels At The Take-Off Site

Measurement And Assessment Of Indoor And Outdoor Ambient Radiation Levels At The Take-Off Site

Abstract

Harmful background radiation in our environment has been identified as one of the primary causes of various ailments such as cancer and tumors in our society today. These Higher radiation levels are emitted from igneous rocks such as granite rocks and soil formed from the weathering of these rocks as well as Radon gas in the atmosphere while lower radiation levels are usually associated with sedimentary rocks.

This research project is aimed at the measurement and assessment of ambient indoor and outdoor radiation levels at the take-off site of Federal University Dutsin-Ma to ascertain the amount of ionizing radiation present. The indoor and outdoor radiation levels were measured in thirty-six (36) buildings, some road pavements and outdoor sports facilities are also considered using a digital radiation detector (Radiation Alert Inspector). While taking measurement readings, the radiation meter was held one meter above the ground oriented vertically upward. For each location, ten readings were taken, five indoors and five outdoors.

From the results obtained, it was observed that the old Biology and Biochemistry laboratories were found to have the highest value of indoor annual equivalent dose rate of 2.27±0.29 mSv/yr and 2.27±0.33 mSv/yr respectively, while the lowest value for indoor annual equivalent dose rate was recorded as 0.85±0.22 mSv/yr at Lecture Halls 3 and 4. The highest outdoor annual equivalent dose rate was recorded at new Physics laboratory as 0.46±0.10 mSv/yr while the lowest outdoor annual equivalent dose was recorded at the recreational building as 0.23±0.03 mSv/yr. The overall average indoor and outdoor annual equivalent dose rates on the take-off site of FUDMA were computed and found to be 1.41±0.29 mSv/yr and 0.33±0.08 mSv/yr respectively.

A comparison of these results with the worldwide average limit of equivalent dose rate of 2.4 mSv/yr recommended by the International Commission on Radiation Protection (ICRP, 1990) for protection of human beings from ionizing radiation, infers that the ambient indoor and outdoor radiation levels at the take-off site of FUDMA are within the safety limits. It is recommended that a further research should be carried out during the dry and rainy season using different radiation detectors and qualitative elemental analysis of the air, soil, water rocks and water be carried out so as to determine the actual radionuclides responsible for the levels of ambient radiation on the take-off campus of Federal University Dutsin-Ma.

Chapter One

Introduction

1.1 Background of the Study

Radiation is any form of energy propagated as rays, waves, or stream of particles which could be ionizing and nonionizing. Ionizing radiation produces ionization when it passes through matter and is more harmful than non-ionizing radiation (IAEA, 1986). Ionizing radiation is that type of radiation which is able to produce ions that is capable of disrupting life processes. Non ionizing radiations are not able to create ions, although they may adversely affect human health in other ways. We live in an environment where we are being exposed to certain amounts of ambient radiation every day, this ambient radiation may be from natural sources (e.g. radon gas, soil, granite rocks) or artificial sources (e.g. x-ray machines, building materials, radioactive wastes from reactors, etc.) in the environment and the level of radiation varies from one place to another (Farai and Vincent, 2006). Radon gas from the earth crust is the most abundant source of natural radiation in the environment. The radioactive disintegration of uranium-238 produces 222Rn which in turn decays with a half-life of 3.82 days (Masok et al., 2015). As it is inhaled, it penetrates into the lungs and the continuous deposition and penetration of such high energy particles through the lungs leads to tissue damage and mutation which leads to incidence of lung cancer.

(Chad-Umoren et al., 2007; Maria et al., 2010). Other natural radiation sources include radionuclides in the soil, cosmic radiation due to ionization of gases in the atmosphere and natural radioactivity due to radionuclides in the body (Osiga, 2014 and James et al., 2015). The materials used in constructing buildings are also major sources of indoor radiation exposure to humans while in the soil, natural radioactivity is mainly due to 238U, 40K, 226Ra which causes external and internal radiological hazard from consumption of crops grown on such (UNSCEAR, 1988). Generally, ionizing radiation when absorbed at higher doses poses health challenges to humans, leading to certain ailments like cancers, tumors, organ and tissue damage, sterility/infertility, genetic mutation, etc. (Jwanbot et al., 2014).

The International Commission on Radiation Protection (ICRP) in 1990 set a worldwide annual equivalent dose rate limit of exposure to ionizing radiation to for the protection of human beings and wildlife (ICRP, 1990) while the average effective dose rate limit of 2.4 was set by the United Nation Scientific Committee on the Effects of Atomic Radiations (UNSCEAR) for most indoor facilities such as research laboratories, conference halls, lecture venues, offices, etc. (UNSCEAR, 2000).It has also been revealed by researchers that, the number of hours residents spent indoors is more than the number of hours/activities they do outdoor. According to Ononugbo et al. (2015), the outdoor activities of individuals add up to approximately 5 to 6 hours a day while the rest of the time 18 to 19 hours of the day is spent indoor either sleeping, studying, resting and the rest. Thus, the indoor radiation in an environment differs from the outdoors. Masashi et al., (2014) asserted that, resident’s exposure to radiations is evaluated by using reduction coefficient for radiation levels in houses and buildings. The reduction coefficient is the ratio of indoor and outdoor ambient dose equivalent rates for evaluating indoor exposure doses and this is provided by International Atomic Energy Agency (IAEA, 1986). It is therefore necessary to know the level of radiation within our living environment because of its health implications to life. The fact that, exposure to high doses of ionizing radiation has implication on human life has been given much research attention in so many places, so as to ascertain the amount of radiation people are being exposed to and to give recommendations.

Tyovenda et al. (2011) assessed the indoor and outdoor ambient radiation level from different locations at the University of Mkar and the results they obtained showed a safety level in most locations of the indoor and outdoor facilities except along the granite paved road way outside the school gate which exceeds the limits of 1 mSv/yr set by the International Commission on Radiology Protection. Sadiq and Agba (2012) reported that the mean outdoor and indoor radiation levels at the Nassarawa State University Keffi was in the range of 0.25 and 1.08 respectively, which were in good approximation with the internationally approved annual dose limits for members of the public (1 ). Masok et al. (2015) assessed the background ionizing radiation sources at the Biochemistry, Chemistry, Microbiology and Physics laboratories at Plateau State University, Bokkos to determine the radiation levels both within the laboratories and their environs using a gammascout which was adjusted to detect the alpha, beta and gamma radiation in . Their results showed that the mean equivalent dose rate per hour for indoor background radiation for the laboratories was found to be 0.256 while the outdoor was 0.249 . The mean annual equivalent dose rate of the laboratories were then computed for indoor and outdoor background radiation level to be 1.54 and 0.44 respectively, and are in a good proportion below the world wide average dose of 2.4 . Jwanbot et al. (2012) measured the background ionizing radiation profile within the Chemistry research laboratory and Physics Laboratory III of the University of Jos and their immediate neighborhood using gamma scout (model GS2 with serial number A20). The results of the radiation levels recorded showed that the Chemistry research laboratory indoor and outdoor radiation levels were 2.111 and 2.081 respectively, while the Physics laboratory III indoor and outdoor ambient radiation levels were 2.733 and 2.435 respectively. The high values obtained which were below the world wide average effective dose rate limit of 2.4 are due to the fact that these science laboratories also harbour a number of active radiation sources.

In more recent times, Ushie et al. (2016) investigated the exposure level to background radiation emitted from laboratories in Cross-River University of Technology (CRUTECH) Calabar, Nigeria. The result obtained indicates that the workers and students operating in the Physics, Biology, Chemistry and Microbiology laboratories were operating within the recommended safety limit of 1.0 while those in the Biochemistry laboratory, Civil, Mechanical and Electrical engineering workshops were operating at 11.6, 10.23, 9.53, and 8.83 respectively, which is way above the threshold value. Similarly, Abubakar et al. (2017)in a research carried out at Asaba Federal Medical Center (FMC) assessed the indoor radiation profile of the center’s radiology department and found out that the Mean Indoor Post Exposure (MIPE) was which inferred that radiation level was kept within the permissible radiation limit as stipulated by the ICRP and UNSCEAR of 1 , thus affirming that the radiological Department of FMC Asaba was safe from excess exposure to ionizing radiation.

1.2 Statement of the Problem

Natural radiation is the major source of human exposure to ionizing radiation and its largest contributing component to effective dose arises from inhalation of radon gas and its radioactive progeny. Background ionizing radiation comes from three major sources, namely terrestrial radiation, cosmic and man-made radiation. Natural background radiation that originate from the terrestrial environments varies tremendously worldwide. Natural radioactivity has great contribution to ionizing radiation to the world population due to its presence in the natural environment. The primary radioactive elements in the earth’s crust are potassium, uranium, thorium and their radioactive decay products.

Exposure to natural radiation can come through inhalation, ingestion or otherwise enters the blood stream through wounds and also from irradiation from external sources such as linear accelerators. Radiation damage to tissues or organs of the body depends on the dose of radiation received or the absorbed dose which isexpressed in a unit called gray (Gy). The potential damage from an absorbed dose depends on the type of radiation and sensitivity of different tissues and organs. The effective dose is used to measure ionizing radiation in terms of the potential for causing harm. Sievert, the unit of effective dose takes into account the type of radiation and sensitivity of tissues and organs.

Radiation studies have shown that radionuclides are known to be associated with organic materials in nature. Therefore, oil, gas and oil field brines contains natural radioactive materials. Human beings are exposed outdoors to the natural terrestrial radiation that originates predominantly from the upper 30 cm of the soil.

1.3 Aim and Objectives of the Study

In line with the study problems stated above, the aim of this work is to measure and analyze the indoor and outdoor ambient radiation levels at the take-off campus of Federal University Dutsin-Ma, Katsina State. The specific objectives of this study are:

1. To measure the ionization radiation in and outside the buildings of Federal University Dutsin-Ma take-off campus.
2. To compute from the data of the field radiation measurements the annual absorbed dose in the air and the distribution of effective dose in land and buildings in milliSeviet per year (mSv/yr).
3. To compare and check the safety of human beings as a result of the computed radiation distribution for the study area using the ICRP (1990) worldwide average equivalent dose rate of 2.4 mSv/yr for human being protection as basis.

1.4 Significance of the Study

This study will expose to the public targets especially, staffs and students of Federal University Dutsin-Ma, Katsina State the ionization radiation that is in and outside the University buildings. This study will also help the management of the University to use collated data to make proper safety measure to affect the negative effect of field radiation on human beings. This study will also serve as reference material material for further studies on this topic or related domain in the future.

1.5 Scope and Limitation of the Study

This study shall only measure the ionization radiation in and outside the buildings of Federal University Dutsin-Ma take-off campus, compute from the data of the field radiation measurements the annual absorbed dose in the air and the distribution of effective dose in land and buildings in milliSeviet per year (mSv/yr), compare and check the safety of human beings as a result of the computed radiation distribution for the study area using the ICRP (1990) worldwide average equivalent dose rate of 2.4 mSv/yr for human being protection as basis. Hence, this study will be delimited to Federal University Dutsin-Ma, Katsina State.

Chapter Five

Summary, Conclusion and Recommendation

5.1 Summary

In this study, our focus was to measure and analyze the indoor and outdoor ambient radiation levels at the take-off campus of Federal University Dutsin-Ma, Katsina State. The study specifically was aimed at measuring the ionization radiation in and outside the buildings of Federal University Dutsin-Ma take-off campus, compute from the data of the field radiation measurements the annual absorbed dose in the air and the distribution of effective dose in land and buildings in milliSeviet per year (mSv/yr), and compare and check the safety of human beings as a result of the computed radiation distribution for the study area using the ICRP (1990) worldwide average equivalent dose rate of 2.4 mSv/yr for human being protection as basis.

The indoor and outdoor background radiation of Federal University Dutsin-Ma take-off Campus was measured in forty-eight (48) different locations using a digital radiation meter (Inspector alert). The radiation meter was held one meter above the ground to capture the average exposure level (height) of the human body and oriented vertically upward during the measurement of readings so as to expose the window of the device to incoming radiation. For each location, ten readings were taken, five indoors and five outdoors. Outdoor measurements for locations like football fields, road pavements and paths were also taken. The coordinates of the geographical locations were taken with use of a GPS. The effective dose readings were taken in milliRöentgen per hour ( ) directly from the display screen of the radiation meter. The results were then converted to micro-Sievert per hour ( ) and then finally converted to micro-Sievert per tear ( . The occupancy factors for indoor and outdoor are 0.8 and 0.2 respectively as recommended by UNSCEAR (2000). The occupancy factor (OF) indicates the proportion of the total time during which an individual is exposed to a radiation field.

5.2 Conclusion

In this work the results of the indoor and outdoor annual equivalent dose rates from lecture venues, block of offices and also the outdoor annual equivalent dose rates from open structures of Federal University Dutsin-Ma take off Campus were measured. The overall mean Indoor Annual Effective Dose Rate (IAEDR) of 1.41±0.31 (0.212±0.04 ) was recorded (i.e. for indoor facilities such as lecture halls, laboratories, office) while the overall mean Outdoor Annual Effective Dose Rate (IAEDR) of 0.33±0.08 (0.227±0.03 ) was also recorded (i.e. for outside buildings, road pavements and outdoor sports facilities). It is worthy to note that all the ambient radiation recorded for all the outdoor facilities fall way below the recommended limit of 1.0 set by the International Commission on Radiation Protection (ICRP) in 1990 while the background radiation for the indoor facilities falls below the worldwide value of 2.4 average equivalent dose limit set for ionizing radiation by the United Nation Scientific Committee on the Effects of Atomic Radiations (UNSCEAR) in 2000. Thus, the ambient radiation levels in the take-off campus of Federal University Dutsin-Ma are within the safety limit and hence, there are no health risks from harmful radiation exposure in the location.

5.3 Recommendation

The radiation level in the University should be properly checked and make sure that its rte isnt harmful to the residents of the environment. Also, further research should be carried out during the dry and rainy season using different radiation detectors and qualitative elemental analysis of the air, soil, water rocks and water be carried out so as to determine the actual radionuclides responsible for the levels of ambient radiation on the take-off campus of Federal University Dutsin-Ma.

How To Get The Complete Material For Measurement And Assessment Of Indoor And Outdoor Ambient Radiation Levels At The Take-Off Site

The Complete Material Will Be Sent to You in Just 2 Steps

Quick & Simple…

Make Payment (Through Transfer) of ₦3,000 to Any of the Account Below

	Acc No: 0811003731
	Samphina Academy
	Current Account

	Acc No: 1225513212
	Samphina Academy
	Current Account

	Acc No: 8143831497
	Samphina Academy
	Digital Account

Or CLICK HERE To Pay With Debit Card

Send the Following Details on WhatsApp ( 08143831497) After Payment

1. Payment Details
2. Email Address 
3. Measurement And Assessment Of Indoor And Outdoor Ambient Radiation Levels At The Take-Off Site

The Complete Material Will Be Sent To Your Email Address After Receiving Your Details
T & C Apply

  Contact Our Help Desk