Abstract
The discovery of the potential of radionuclides in the management of medical conditions has seen an increase in the use of radionuclides in medical facilities. In addition, numerous studies are carried out to find new cures and improve the efficiency of available radioactive therapies. Consequently, there is an increase in the production of radioactive waste, which poses numerous hazards to patients, radiation workers, and the environment.
The National Regulatory Commission along with federal agencies oversees the use of radionuclides and the management of the ensuing waste. As a result, policies that ensure the safety of all involved parties have been set. The effective management of radioactive waste from medical facilities involves proper education and the provision of the appropriate facilities in the medical facilities that handle radioactive waste.
Introduction
Radioactive waste can be defined as the spin-offs of reactions that emit radionuclides. Hospitals and clinics extensively use radioactive isotopes for investigative and restorative purposes. Consequently, these establishments spawn voluminous quantities of waste that are considered harmful bearing in mind the obvious possibility of transmission of infections. It is estimated that health facilities release approximately two kilograms of waste per bed daily (Khan et al. 40).
On average, about 80% of the waste poses no threat while 10% is infectious. The remaining fraction does not cause infection although it is harmful. Increasing incidences of viral infections such as hepatitis and HIV/AIDS have led to increased concerns on the management of hospital waste. Consequently, numerous policies have been developed to ensure secure and reliable methods of waste disposal are used.
The advancement in medical technology has seen the increased use of radioactive isotopes in the diagnosis and treatment of various conditions. The commonly used isotopes in the medical field include Carbon-14, the three isotopes of Iodine (123, 125, and 130), Technetium-99m, Fluorine-18, and Tritium (Khan et al. 40). In addition, thousands of studies involving nuclear medicine continue to be performed all over the world. This paper discusses the types of medical radioactive waste generated in hospitals, regulations governing the management of radioactive waste, and facilities that handle radioactive waste.
Types of Medical Radioactive Waste Generated in Hospitals
Waste from health facilities causes two classes of hazards, which are classified as radiological and non-radiological hazards. Radiological hazards include the exposure of individuals to lethal doses of radioactive radiation. Non-radiological hazards, on the other hand, are further grouped into physical, chemical, infectious, and explosive hazards. Physical dangers include the possibility of bodily injuries such as cuts and bruises from medical equipment while chemical injuries include the possibility of undesirable chemical reactions from the mixing of incompatible wastes. Biological waste or biohazards are medical waste contaminated with human blood or other body fluids, which pose a risk of transmitting infectious diseases (Evdokimoff, Cash, Buckley, and Cardenas 209).
The radioactive waste generated by health facilities can be categorized into six main groups namely gaseous waste, liquid waste, general waste, spent sealed sources, solid waste, and decommissioning waste (International Atomic Energy Agency 8). Radioactive waste in the liquid form includes polluted water from chemical processes, solvents, discarded liquid radiopharmaceuticals, chemotherapeutic medications, polluted soils, and scintillation liquids.
The waste also includes body fluids such as urine and blood. Investigative imaging for the evaluation of lung function often uses radioactive gases such as Xenon-133 and 81mKr. The properties of these gases hinder the efficacy of gas treatment processes. Consequently, the only available option is to release the gases to the surroundings via exhaust pipes.
Radioactive waste in solid form comes from protective garments, gloves, masks, filters, paper wipes, metal, syringes, glass vials, and plastic sheets among many other items (Krieger, Van Baalen and Walters 109). These items are mainly used during medical procedures that involve radioactive radiations. In addition, clothing and utensils used by patients receiving elevated dosages of radiation therapy such as Iodine-121 also make up radioactive waste material. Radioactive waste in solid form contains small quantities of radioactive material compared to liquid waste.
The termination of the clinical life of sources of radioactive radiation leads to the generation of radioactive waste, which needs to be discarded safely. Such substances are referred to as spent sealed sources and are divided into four categories depending on the concentration of radioactive substances and their half-lives. The first category comprises waste such as 192Ir, which has elevated levels of activity and short half-lives. The second category includes substances with low levels of activity, which often find use as standards and calibration reagents. The third class encompasses substances that pose a higher risk of exposure due to emanation and leakage. These substances require stringent measures when handling them. The final category includes waste with low levels of radioactivity and half-lives that surpass 100 days.
Medical facilities such as oncology centers sometimes use accelerators during their operations. The decommissioning of these accelerators may lead to the emission of neutrons whose energy exceeds 10 MeV. Such neutrons lead to unnecessary activation of the surrounding materials.
Regulations guiding the Use of Radioactive Substances for Medical Purposes
The responsibility of regulating the medical usage of ionizing radiation is disseminated among several authorities such as the National Regulatory Council (NRC), federal states, and regional government organizations. The NRC is charged with the mandate of controlling the possession and use of byproduct and source radioactive substances in the medical field. Byproduct material is useful in processes such as calibration of equipment, manufacture of radioactive drugs, analysis of bone minerals, and gadgets that carry out fluorescence imaging and brachytherapy (NRC par. 1).
Source material, on the other hand, is utilized in radiation protection and designing of equalizers in some gadgets. In addition, certain models of pacemakers are run by cells that contain nuclear substances. Therefore, the NRC provides special licenses to authorize the use of byproducts for purposes other than the administration of carbon-14 containing capsules during in vivo diagnostics. This license applies to four categories of byproduct materials as stipulated by 10 CFR Part 35. The four categories are diagnostic medical use, therapeutic medical use, medical research, and in vitro diagnostic tools.
In medical diagnostic use, the usage of byproduct radioactive material is indicated in radioactive uptake, strength, secretion, imaging, or diagnosis of conditions at localized positions in medical or research processes. The associations of radiolabeled medications with bodily processes help in getting medical data. In such procedures, it is required that sealed sources provide the radiations necessary for the imaging procedures, which may be aimed at establishing tissue density. The use of portable imaging gadgets in dentists and podiatry also falls under this category.
Therapeutic medical use of radioactive material entails the delivery of analgesic or curative medications to their target organs with the aid of nuclear materials. In most instances, such therapies are applicable in the treatment of cancer. However, other mild conditions such as restenosis (blocked blood vessels) can also be managed by intravascular brachytherapy radiation.
Under medical research use, the application of byproduct materials in human candidates is only allowed when the researcher has a 10 CFR Part 35 medicinal use approval. Nuclear material can be used in human subjects in several ways such as observing a human research subject’s response to a treatment that does not contain radioactive material using a radioactive substance. It may also entail clinical investigations to establish the safety and efficacy of novel radioactive drugs or gadgets. Nevertheless, the actual medical investigation must comply with the stipulations of the 10 CFR Part 35 regarding the possession and use of byproduct materials.
The use of byproduct radioactive materials during ex vivo indicative investigations applies only to health facilities and private doctors with the controlled substance as in vitro indicative analysis kits. These individuals are exempted from the stipulations of the ‘medical use license’ since these items are not included in 10 CFR Part 35.
However, the NRC only oversees the management of certain groups of radioactive substances in the medical field. These categories include byproduct materials (those generated by reactors), source materials (uranium and thorium and their related waste), and special nuclear material, which includes substances contaminated with uranium and plutonium. The usage and management of other radioactive waste such as innate radioactive substances (radium and radon), “particle-accelerator produced radioactive material” and machines that spawn radioactive radiations are under the jurisdiction of the State (International Agency of Atomic Energy 13). As a result, pharmaceuticals that perform positron-emitting tomography are regulated by the State.
Management of Radioactive Waste
The most important aspect of hospital waste management is ensuring that any unused radioactive substances, as well as items contaminated with the waste, are eliminated safely. It is vital to make certain that radiation workers and the entire community are not exposed to radiation concentrations that surpass the set threshold. Observing radiation exposure limits minimizes the possibility of short-lived and long-standing consequences of ionizing radiation in humans and animals. In addition, proper radioactive waste practices safeguard the environment from the harmful effects of radiation. Therefore, it is vital that any health facility that intends to use radioactive isotopes guarantees that structural and functional considerations are in place to contain radiations within permissible levels.
The management of radiation must uphold the fundamental tenets for radiation protection. These tenets include the principle of justification of practice where radiation is only used if the benefits prevail over the dangers. Another principle is the optimization of practice where the quantity of individual doses and the number of people in contact with the radiations is kept to the minimum possible (the ALARA principle). In addition, every hospital worker should be examined to assess the effects of exposure. The surroundings of the hospital ought to be regularly scrutinized to ensure that damage to the environment does not occur.
Conversely, radiation equipment should be monitored to ascertain that they meet the required standards that protect the workers from radiation risks. Each health facility must also have a certified radiation safety officer to supervise all facets of radioactive waste management in conformity with the NRC and the International Commission on Radiation Protection.
The International Atomic Energy Agency provides a sequential procedure for the management of radioactive waste in a medical facility (13). The scheme begins with the purchase of the radioactive isotopes followed by the application of the isotope, which leads to the production of radioactive waste. The collected waste is then separated according to its characteristics. For example, the waste can be separated according to the half-life where radioisotopes with long half-lives are separated from those with short half-lives. The waste can also be separated according to the type of radioactive radiation emitted.
For instance, gamma-emitting waste is separated from beta-emitting waste. The long-living waste then undergoes a pretreatment process followed by a final treatment procedure at a central waste treatment facility. The short-lived waste, on the other hand, is stored to allow it to undergo radioactive decay. Thereafter, a control measurement is performed to ensure that complete decay has taken place after which four main steps are performed.
The first step is a treatment for disinfection followed by incineration of non-biodegradable waste. Quality control is then performed to ascertain that the waste does not pose any hazard to the environment. The treated waste is ultimately released as municipal refuse. Separation of the waste is crucial because it determines the effectiveness of the quality control steps. It is difficult to determine whether complete decay has taken place when looking for the emission of beta particles in the presence of gamma-emitting waste in the same sample.
The management of radioactive waste from medical facilities varies from one country to another because the frequencies and levels of operations that use radioactive radiation vary from country to country. However, the above-mentioned procedure guides the management of radioactive waste from medical facilities regardless of the country. In Finland, for example, 33 out of 43 nuclear medicine departments carry out radionuclide therapy (European Commission 18).
There is a distinct location for in vitro analysis far from the nuclear medicine departments. In addition, each facility has very few employees whose number does not exceed twenty (European Commission 20). Each facility has three radiation specialists namely a physicist, a radiochemist, and a nuclear medicine doctor. Various operations are performed in specialized rooms, which are situated in one restricted region. These rooms include a groundwork area, an injection area, and a patient assessment room. A waiting area with sanitary installations is also available for patients. The waste collection room is set apart in an isolated section. However, the waste collection room may be adjacent to the groundwork room.
Requests to purchase radioactive materials are handled under the control of the radiation safety officer. In addition, deliveries are made straight to the facility to prevent damage and misplacement of radioactive materials. Records of all purchases are then kept carefully and backed up on computers. The storage of radioactive materials is in the groundwork room, which is also referred to as the preparation room or “hot area.” Thereafter, the prepared doses are taken to the treatment room in the form of injections or capsules. The ensuing waste is then gathered in the hot room or an adjacent room from where transfers to the waste storage areas are made.
The preparation of universally documented procedures is another useful feature in the effective management of radioactive waste. The guides include the precise details of the necessary procedures such as the steps to follow when segregating waste at the source and the right containers to be used for waste collection. In addition, the members of staff ought to receive adequate training in the management of waste. The overall management of the facility needs to provide support to ensure that the set policies regarding radioactive waste are implemented (International Atomic Energy Agency 13).
Another useful strategy in the management of radioactive refuse is the diminution of their production in medical facilities. This strategy should aim at lowering the quantities and activities of radioactive waste. A study carried out by Krieger, Van Baalen and Walters (109) reveals that reducing the volume of radioactive waste not only increases the efficiency of the management process but also lowers the overall costs incurred in waste treatment. The need to use radionuclides in the treatment of patients should be justified. Consequently, the lowest effective dose should be computed, and only the right quantities are obtained (Siegel 50).
Research experiments should also be designed appropriately to determine the right quantities of radionuclides to be used. The possibility of using alternative treatments or technologies should also be considered to minimize the production of radioactive waste. For example, the utilization of chemiluminescent and colorimetric assays instead of radioimmunoassay is a wise decision in minimizing radioactive waste. If radionuclides must be used, then short-lived radionuclides should be utilized instead of long-lived ones because short-lived radionuclides allow storage for decay and elimination at clearance levels. Additionally, non-radioactive waste should not be mixed with radioactive materials. Such a move diminishes the volume of radioactive waste by lowering cross-contamination and eliminating the need for decontamination steps.
Facilities that Handle Radioactive Waste
Facilities that handle radioactive waste need to be well planned from the beginning to ensure that they are capable of handling the waste effectively. A complete waste management program is obtained by making an exhaustive prior evaluation to ensure that the key objective is to prevent and minimize waste while safeguarding against the harmful effects that come from the waste. The evaluation involves meticulous analysis of the entire radionuclide record and usage patterns, the type of waste, and the quantities generated. The assessment also needs to consider the possible methods of disposal.
However, the assessment should be performed at the initial planning stages before a facility is created so that certain specialized features can be incorporated in the building plan of the facility (International Atomic Energy Agency 12). However, in certain instances where there is an existing facility, the evaluation may still be performed to improve the efficacy of the waste treatment process. In such cases, it is vital to harmonize the waste management activities of the various laboratories within the facility. Nevertheless, the appropriate waste management practices can only be chosen following an evaluation of all uses of radionuclides within the facility.
Conclusion
The production of medical waste is inevitable due to the rising need for radionuclides in research and therapeutics. Such waste poses extensive risks to workers in medical and research facilities. However, careful planning and observation of the policies that govern the use and management of radioactive materials can go a long way in mitigating these dangers. Facilities that generate medical radioactive waste need to be adequately equipped to handle their waste without exposing their workers to radiation hazards. In addition, the workers need to have sufficient training to ensure that the right procedures are followed in the management of radioactive waste.
Works Cited
European Commission 1999, Management of Radioactive Waste Arising from Medical Establishments in the European Union. Web.
Evdokimoff, Victor, Charles Cash, Kevin Buckley, and Ariosto Cardenas. “Potential for Radioactive Patient Excreta in Hospital Trash and Medical Waste.” Health Physics 66.2 (1994):209-211. Print.
International Atomic Energy Agency. Management of Radioactive Waste from the Use of Radionuclides in Medicine, Vienna, Austria: International Atomic Energy Agency, 2002. Print.
Khan, Shoukat, Syed AT, Reyaz Ahmad, Tanveer A. Rather, Ajaz M, and Jan FA. “Radioactive Waste Management in A Hospital.” International Journal of Health Sciences, Quassim University 4.1(2010):39-46. Print.
Krieger, Kenneth, Mary Van Baalen and Christopher Walters. “Radioactive Waste Minimization at a Large Academic Medical Facility.” Radiation Safety Journal 82.5(2001): 108-110. Print.
NRC n.d., Medical Uses of Nuclear Materials. Web.
Siegel, Jeffry A. Guide for diagnostic nuclear medicine. Reston, Virginia: Society of Nuclear Medicine, 2002. Print.