The Practice of Radiation Protection in Conventional Radiography Department in Four Hospitals in Yaounde, Cameroon

Emmanuel N Tufon, Ogugua Victor N. and Lukong Kinyuy F.

Department of Medical Biochemistry, St. Louis University Institute of Health and Biomedical Sciences Mile 3 Nkwen, Bamenda

Department of Medical Biochemistry, University of Nigeria, Nsukka - Nigeria

ABSTRACT:

The aim of this study was to assess the practice of radiation protection and compare it with the stated norms of radiation protection. A cross – sectional hospital based descriptive design was undertaken in four hospitals in Yaounde, Cameroon in which all the technologists (17) working in the x – ray department of the selected hospitals took part in the study. The assessment was carried out by the use of a questionnaire survey. From the results obtained, all the hospitals had lead aprons and shields but only one hospital gonad shield and lead gloves. 47.06% had been trained for at least three years. Radiation protection supervisors were present in two of the four hospitals but only one hospital had a warning red light in good working condition. In conclusion radiation protection in conventional radiography is not properly practiced as not all norms are respected and therefore remains a problem that needs to be solved.

KEYWORDS: Radiation, Protection, Conventional Radiography, Yaounde, Cameroon

INTRODUCTION:

Radiation (energy in the form of high speed particle and electromagnetic wave) has been an ever present ingredient in the evolution of life on earth (Moss and Cox, 1989) and man has always been exposed to radiation from different sources (vattenfall, 2010). Though it has always been, its use in diagnosis only became obvious following the discovery of x – ray (Moss and Cox, 1989). Despite its importance in diagnosis, ionizing radiation is by far the most potent agent known to man (Dendy and Heaton, 1987). Radiation causes biological damage by deposition of energy in the body tissues which can cause cell damage or cell death (Environmental Protection Agency, 2007). The biological effect of radiation are put into two basic categories, stochastic effect (due to chronic exposure) and non – stochastic effect (due to acute exposure) (Cember and Thomas, 2009). The intensity of the biological effect depends on the total energy of radiation absorbed per unit mass measured in greys but however, different tissues and organs have varying sensitivity to radiation exposure. There is substantial and convincing evidence that the biological effect of radiation at high doses like those used in radiation therapy (Health Physics Society, 2004). In order words, it is assumed that no radiation exposure is completely risk free (Environmental Protection Agency, 2007).

Though the effects of radiation are real, it can be used safely if handled properly. This is made possible by the science of radiation protection whose overall objective is to provide an appropriate standard of protection for man without unduly limiting the beneficial practices giving rise to radiation protection (Grover et al, 2002). Three categories of persons are considered as far as radiation protection is concerned; those occupationally exposed (personnel), the patients and the general public (Cember and Thomas, 2004).

The above objective can be achieved if the rules and regulations governing the ‘safe’ use of radiation are applied. These rules are set by the International Commission on Radiation Protection and International Atomic Agency which the National Radiation Protection Agency in Cameroon adopts. This study therefore looked at how these rules and regulations are implemented in some of our hospitals in Cameroon to protect the personnel, patients and public from the biological effects of radiations.

MATERIALS AND METHODS:

Study Area:

This cross – sectional hospital based descriptive study was carried out in four hospitals in Yaounde; Hôpital Général, Hôpital Militaire, Hôpital Gynéco – Obstétrique et Pédiatrique and Centre Médical la Cathédrale

Study Population:

All the technologists (17) working in the x – ray department of the selected hospitals took part in the study.

Data Collection:

Pre – tested standard questionnaires (open and closed - ended) were administered (face – to - face) to the technologists to collect data.

Data Analysis:

Survey data were analyzed using SPSS version 17.0 to produce frequency tables.

Ethical Considerations:

The survey data were collected after the individuals read and signed an informed consent form.

RESULTS:

Demographic Profile:

The demographic profile of the respondents (table 1) showed that majority (52.94%) of the technologists working in the field were females with greater percent of the technologists trained for less than 3 years (52.94%). Also, most of the technologists (41.18%) had a work experience of a year or less

Table 1: Demographic Profile of Respondents

Variable Percent (%)

Sex

Male 47.06

Female 52.94

Duration of Training

1month 5.88

6months 5.88

1year 5.88

2years 35.30

3years 47.06

Work Experience (year)

0–1 41.18

2–3 11.76

4–5 23.53

10–25 23.53

Technologists’ Understanding of Radiation Principle:

The results obtained showed that most of the technologists understand the principles of justification (76.47%), optimization (64.70%) and dose limitation (88.24%)

Table 2: Technologists’ understanding of current radiation protection standards that are based on three principles

Principle Understanding Percent (%)

Justificatio Yes(13) 76.47

No(4) 23.53

Optimizat Yes(11) 64.70

No(6) 35.30

DoseLimitat Yes(15) 88.24

No(2) 11.76

Technologists’ Understanding of the Measures of Radiation Protection:

Most of the technologists (94.12%) understood time as a measure of radiation protection while majority (52.95%) did not understand distance as a measure of radiation protection. The shielding materials available in the selected hospitals are shown on table 3b

Table 3a: Technologists’ Understanding of Distance and Time as a Measure of Radiation Protection

Measure of Radiation Understanding Percent (%)

Protection

Time Yes (16) 94.12

No (1) 5.88

Distance Yes (8) 47.05

No(9) 52.95

Table 3b: Available Shielding Materials in the Selected Hospitals

Shielding Materials Hospital With Hospitals Without

Lead Screens 4 0

Lead glasses 0 4

Gonad Shields 1 3

Lead aprons 4 0

Lead gloves 1 3

Technologists with Personal Dosimeter:

Most of the technologists (70.59%) did not own personal dosimeters but most (60%) of the technologists that owned personal dosimeters had had them analyzed.

Table 4: Technologists with Personal Dosimeters

Variable percent

Yes No

Personal dosimeters 5 (29.41%) 12 (70.59%)

Dosimeter monitoring 3 (60%) 2 (40%)

Presence of Radiation Protection Supervisors and Red Lights above the Door in the Selected Hospitals:

2 out of the 4 hospitals had radiation protection supervisors and 3 had red lights above the door but only 1 out of the 3 had the light functioning

Variable Hospital Hospital

With Without

Radiation protection supervisor 2 2

Red light above the door 3 1

DISCUSSION:

This study considered the principles and measures of radiation protection stated by the International Atomic Energy Agency (IAEA) whose standards Cameroon adopts.

From the demographic profile, none of the technologists were trained for more than three years. This could possible one of the factors contributing to non – practice of radiation protection.

The current radiation protection standards are based on three principles; justification, optimization and dose limitation (Grover et al, 2002). According to IAEA, technologists can refuse to do an examination if the exposure is not justified. From the results on the principle of justification, most of the technologists understood but because some did not (23.53%), there is a probability that patients may be exposed unnecessarily to radiation (x - rays). Considering the principle of optimization, IAEA states that exposure should be kept as low as reasonably achievable (ALARA) but from this study, 35.30% of the technologists did not know of ALARA which is probable that patients might be exposed to unnecessary x – rays. According to the principle of dose limitation as stated by IAEA, exposure of patients should be the minimum necessary to achieve the required diagnostic objective. From this study, most of the technologists (88.24%) understood this principle while a few (11.76%) did not.

There are three measures of radiation protection; time, distance and shielding. IAEA explained that whenever feasible, shielding of radiosensitive organs such as gonads, lens of the eye and thyroid should be provided but from the results obtained, all the shielding materials are not available thus the principle cannot be completely applied. Furthermore, there are dose limits for technologists, 20 mSv/year averaged over five years (ICPR, 1990). A device that could be used to monitor the dose received by technologists is the dosimeter. Every technologist is expected to wear a dosimeter while at work (Hjardemall, 1994). From the results, 70.58% of the technologists did not have and of those that had, 40% of them have never had their dosimeters analyzed. There is therefore a greater probability that dose limits might have been exceeded.

Under Ionizing Radiation Regulations (IRR) 1999, the radiation employer shall appoint one or more suitable radiation protection supervisors for the purpose of ensuring compliance with these regulations with respect to work carried out in any are made subject to local rules (IRR. 1999). As observed from the results of this study, 50% of the hospitals did not have radiation protection supervisors and this absence could possibly lead to non – compliance with norms of radiation protection.

Accidental exposure of all persons around the x – ray rooms could be avoided by the use of red lights above the doors at patient waiting areas to indicate the passage of x – rays (Grover et al, 2002). According to this study, red lights were available in 3 hospitals (75%) and even when available, some were not functional (66.67%). This indicates that there are chances of accidental exposure which could be avoided if the red lights were present and functional.

CONCLUSION:

Based on the results of this study, not all norms of radiation protection are respected. This implies that radiation protection in conventional radiography is not properly practiced and therefore remains a problem that needs urgent attention by the government of Cameroon.

ACKNOWLEDGEMENT:

We wish to acknowledge the chief medical officers of the selected four hospitals; Hôpital Général, Hôpital Militaire, Hôpital Gynéco – Obstétrique et Pédiatrique and Centre Médical la Cathédrale and the C.E.O of Saint Louis Group, Dr Nick Ngwanyam for their support.

REFERENCES:

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3. Environmental Protection Agency (2007). Ionizing Radiation Fact Book, United States of America

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Received on 21.07.2012

Modified on 28.07.2012

Accepted on 06.08.2012

Research J. Pharmacology and Pharmacodynamics. 4(5): September –October, 2012, 304-306