A growing concern and way forward.
What is Biomedical waste
The BMWs are generally different from the normal wastes. They may be either in the form of liquid or solid. Some of them are noninfectious but hazardous and upon disposal without treatment cause environmental pollution. According to the environmental impact, they are of two types i.e. hazardous and non-hazardous.
The hazardous BMWs are generally accounted for 10–25%. There is a certain fraction of the BMWs containing infected human tissues, blood, excreta, etc. They are the carriers of the pathogens like bacteria, viruses, fungi, and parasites. Generally, pathological or surgical wastes like human anatomical tissues, fetuses, organs, and body fluids are carriers of the pathogens. The biochemical laboratory generates bacterial and viral cultures, stock and used media, quality control reagents, serological enzymes, and disposable single-use apparatus. They are potentially being contaminated by different pathogens as well as contain toxic or radioactive chemicals. Pharmaceutical wastes like expired and unused drugs are hazardous to the environment as they contain various chemical and radioactive elements. The chemical components present in them are prone to different abnormal chemical reactions in the open environment, which produce next-level toxic chemicals and are too dangerous to the environment .There are some cytotoxic drugs used for molecular disorders like DNA damage. They are directly carcinogenic upon direct inhalation and ingestion, so they must be handled with proper care. Other laboratory reagents like solvents and cleaning gels are highly toxic to the environment. Presently a new therapy is developed, which is called nuclear medicines therapy. This therapy uses different radioactive isotopes in the patients. Those patients produce radioactive isotopes in their urine and excreta, which need special attention.
Non-hazardous BMWs include different materials like unconsumed foods, kitchen wastes, cardboards, plastics, thermocol, and papers generated from various hospital activities, subject to the conditions that they are non-contaminated. Unconsumed food and kitchen wastes contribute to the majority of the non-hazardous BMWs. The amount of non-hazardous BMWs is accounted for 75–95% of the total BMWs of a hospital. They are non-toxic and do not need any special attention for the pre-treatment before their disposal or reuse. They are generally transported to different treatment systems established for the municipal solid wastes (MSWs) governed by the concerned city or township administrations . They are used to produce either biogas or manure. Since their amount is much more than the hazardous BMWs, segregation at the source is exclusively considered to minimize the treatment and disposal load. Upon performing the segregation effectively, the overall cost of BMW management can be reduced dramatically.
Liquid BMWs are generated from different departments and activities of the hospitals like dialysis units, culture and specimen collection centers, chemotherapy units, spinal fluids, blood, by-products of blood, amniotic fluids, and several bodily secretions and fluids. They are collected in the leak-proof containers. They undergo either chemical or autoclave treatment methods to decontaminant before their disposal to the public sewer systems. Both the treatment methods should be standardized according to the specification of the liquid BMWs. Handling of the liquid BMWs needs skillful workers. Thereby proper training and knowledge are required by the concerned people working in the treatment facilities set up for the liquid BMWs.
Segregation method for BMWs
Segregation of the BMWs at different entry points is a strategic management policy which reduces its management cost dramatically .An effective and accurate segregation method is necessary for better results. The accuracy of segregation results in the easiness of the final treatment and disposal process. Improper segregation method leads to different adverse effects on the health sectors as well as the increased cost of BMW management. Therefore, regular training and updated education should be given to the workers related to the segregation process. Further, the workers involved in the segregation process need to follow the strict safety protocol as they are directly exposed to the diverse group of BMWs. Many hospitals have their own set up to segregate at the entry point of BMWs. For simplifying the segregation process, classification of the BMWs is done by different color codes such as yellow, red, blue, black, and white. Different trash boxes are placed in the hospitals according to the color codes in order to execute the segregation at the point of entry. Hospital staffs, patients, and their attendants are sufficiently instructed by the pictorial form to use the specific box for putting the BMWs according to their color codes (CPCB, 2020). Willingness to follow the instructions does a lot of work, especially for the people of developing countries like India. However, the complete outcome of this method is yet to be achieved in developing countries including India Upon inefficient segregation at the entry points, ultimately the hospital establishments use the additional workers and time in order to segregate the BMWs at the collection points, which is definitely a cost-borne load. However, performing the segregation at the entry points is the priority over the segregation at the collection points and more focus should be given to achieve the complete execution of the former technique
Location of treatment facilities
The distance between hospitals and their treatment facilities is an important factor in the BMW management. The segregated BMWs are generally transported to the treatment facilities in different labeled bags with the help of trolleys or BMW transit trucks. Transportation by dragging the filled BMW bags is strictly prohibited. If the distance is more, it takes a long time to reach the destinations. Durable transportation leads to the possibility of tearing of the baggage, which in turn produces a bad smell as well as a small mass loss through the route without knowledge of the vehicle drivers. Therefore, BMW treatment facilities should be set up at a suitable location near the hospitals. Transportation can be further optimized by the computer-based algorithm for the quick and errorless carriers of the BMWs. However, the hi-tech method can be applied upon intensive practical testing.
BMW disposal techniques
Appropriate disposal techniques need to be implemented based on the properties of BMWs that are collected and segregated. Different conventional and alternative technologies are practiced in India for the treatment of BMWs.
Conventional techniques used for BMW Management.
Steam treatment or autoclave technique
Autoclave technique is an efficient process to disinfect various BMWs. It utilizes high temperature and pressure to sterilize the infected BMWs. But it is suitable for a small amount of BMWs generated in different nursing homes. It requires less time. It generates high-efficiency particulate air (HEPA) which should be filtered at the overhead vents. The disinfection is optimized when the autoclaves run at a condition of pressure between 1540 and 2280 mmHg, temperature 121 °C, and time 30 min. The proficiency of every autoclave cycle relies on time stacking of configuration and packing density, load size, the integrity of packet, temperature, pressure, process sequence, physical and chemical properties of BMWs, and residual air. It is a familiar technique and does not need an expert to run this process. The hazardous BMWs are generally treated by the autoclave technique prior to their disposal. The BMWs undergo this process can be reused, but shredding of materials during the process make them unusable It is an eco-friendly process and its operating cost is less; however, its installation cost is expensive. It produces toxic effluents, which is a major drawback of its application. It is not suitable for chemical and pharmaceutical wastes as autoclaving these wastes produces unpleasant odour and toxic fumes.
The dry heat technique is used for sterilization. It uses very high temperature to kill bacterial spores and microbes. It is generally used for handling a small volume of BMWs. It is used on dry items like glassware’s, metal equipment, paper-wrapped items, powders, oil, etc. In this technique, moisture-free high-temperature air is used over a lengthened period for the sterilization of BMWs. A lot of heat input is required in this process as it uses the conduction, convection, and thermal radiation method of heating. It is an eco-friendly as well as an inexpensive process. It is a non-corrosive treatment process suitable for metals and sharp objects; however, it cannot be used for plastic or rubber items as there is a possibility of damaging these items due to exposure to heat over a prolonged period. Therefore, both temperature and time should be optimized to minimize the volatile organic carbon released from the plastic BMWs during the dry heat treatment.
Chemical treatment is a disinfection technique used for the pre-treatment of COVID-19 related BMWs. Chemical disinfectants like Chlorine(Cl2), Sodium hypochlorite (NaOCl), Chlorine dioxide(ClO2), Ozone(O3), and UV irradiation are generally used in this process. This process is conducted in a covered system for a fixed period so that all pathogens and organic substances are effectively inactivated. The possibility of chemical aerosol formation during the process is minimized by using the high-efficiency particulate absolute filters. The major disadvantage of the process is that it releases large-scale Cl2 gas into the environment. Both residue and effluent of the process should be analyzed and disposed of with proper regulation. Also, it generates toxic effluent which requires further treatment resulting in the high expenditure of the overall process. Combining the process with a mechanical shredder is used for the complete disposal of BMWs. It is a simple disinfection technique, but the BMWs should be properly shredded before they undergo the chemical disinfection.
Incineration is a common practice and widely used process for the treatment of BMWs. All hospitals have mandatory set up of an incinerator. It is conducted between 800 and 1200 °C in the presence of sufficient air for the complete obliteration of pathogens and organic wastes, which reduces the BMW volume and mass up to 90 and 75%, respectively (Gautam et al., 2010). The aerated burning process generates flue gas containing different toxins like furan and dioxins. Therefore, it needs a secondary treatment plant or a high-quality flue gas cleaning system in order to mitigate air pollution. Also, the ash generated from the incinerators should be properly characterized before its disposal following the statutory regulations. Incineration is a high energy-intensive treatment process and combined with the secondary treatment plant for the toxins makes the overall process expensive. However, its high efficiency for the BMW treatment makes it the most suitable and widely adopted process by different countries. According to the CPCB reports, there are 232 incinerator plants available in India for the treatment of BMWs. Incinerator ash is generally inert towards chemical reactions; however, its direct applications create a problem due to the environmental leaching ability The incineration process produces a huge volume of ash which contains heavy metals and inorganic salts . There is a risk of environmental leaching capacity of different metals and ions that further contaminant the groundwater upon disposed of as landfill .The toxic byproducts of the incinerators can be minimized by the combined effect of the efficient segregation system, combustion efficiency of the incinerators, and high-quality flue gas scrubber (Kumar et al., 2021). Alternative methods have been applied for the utilization of its value as concrete, cement mortars, road and asphalt pavements, and agriculture. The environmental leachability of metals and ions is reduced significantly by modifying the raw ash. Since incinerator ash is chemically inert, it must undergo chemical activation or surface area modification before applying in the product developments (Rajor et al., 2012). Therefore, evaluation of the ash accurately is necessary before using them in some applications.
Encapsulation and inertization
This is exclusively a disposal technique that can only be executed after the complete disinfection of the BMWs. In this process, the raw BMWs are ground or broken into small chunks with the help of a crusher machine and then disinfected (Singhal et al., 2017). The disinfected chunks are stared in metallic drums followed by shielding with the plastic foam and then disposed of as the landfill. This technique is adopted only when there is no other physical or alternate method available for the disposal. This is practiced for the small volume of BMWs. The equipment and operation cost are simple and less, respectively. This technique is often used during the pandemic period when the daily BMW generation exceeds the capacity of treatment facilities. During the pandemic, many countries have used this ad-hoc technique for the emergency management of the huge COVID-19 related BMWs. Although encapsulation is simple to execute, it is considered an outdated technique.
Sanitary landfill is a simple and inexpensive disposal method for disposal of the BMWs. It can be conducted in the existing municipal waste management system. It is the traditional landfill technique and completely banned because of its environmental concern which includes the decomposition of waste resulting in the production of landfills leachate and greenhouse gases. This method can only be adopted if there are no acceptable means of treating the waste before disposal. Few things are considered before the landfill that the site should be geographically isolated and away from the water stream, the operation is managed by a competent authority, and there is an acceptable limit to the quantity that can be land filled at a location.
In this process, a shredder is used to cut the pre-treated BMWs into small chunks. The shredders should be operated by a competent staff. Shredders are generally built-in devices to the integrated chemical or thermal disinfection system. This technique facilitates the recycling of plastics and significantly reduces the volume of BMWs. Metallic wastes should be avoided in the shredders as they can damage the metal blade on them.
The COVID-19 pandemic may be over by the end of 2022, but we need to be ready for a possible massive pandemic in the future. During the ongoing pandemic, the BMWs from different hospitals are quantified accurately, but the household wastes from different home isolation places confuse the generation of exact mass and volume of the infectious BMWs . So, there is a need for proper guidelines to quantify the BMWs generated from both hospitals and infected households for lessening the spread of COVID-19 and other viral diseases. The timely collection of wastes from the infected houses without other household wastes is very important. Local administrations should have a close eye and be vigilant about the matter. Proper care must be taken for the complete separation and frequent collection of the infected wastes from the houses. This action has an indirect effect on minimizing the COVID-19 related BMWs. The small thing makes a huge impact. Throwing the used face masks and tissue papers here and there is a common and unhygienic practice in developing countries like India. Therefore, an adequate number of special yellow boxes with proper labeling must be fixed at different public places for the disposal of the face masks and tissue papers used for sneezing and coughing by the general public. Also, automatic sanitizer machines should be fixed at different markets and crowded places. The training and education regarding handling the BMWs are generally provided to the health care workers. This education should be implemented in the local communities and schools as one of the co-curricular activities for educating both adults and children. Pictorial information about the handling of infectious wastes at different places may effectively help in the awareness among different groups of people.
The new treatment techniques like heat, chemicals, a combination of heat and chemicals, and irradiation have great potential for the BMW management. These new techniques can address the underlying problems in the conventional BMW management by minimizing pollution, reducing toxin formation, and efficient volume reduction. Advanced techniques like plasma pyrolysis, sharp/needle blaster technology, PIWS-3000 technology, microwave treatment, alkaline hydrolysis, steam sterilization, and biological treatment emerge as the potential candidate for the new age BMW management, Solar disinfection enters into the BMW management in the semiconductor era where solar cook systems can be used for the disinfection/decomposition of the BMWs. However, the efficiency of the solar disinfection system should be further evaluated and standardized). Nanomaterials have been developed to decontaminate different solid wastes. They are used as the photocatalyst for the simultaneous degradation and generation of the dead cancer tissues and the electricity, respectively. The photocatalytic degradation ceases the toxin emission which is the major drawback of the incinerators. But there are only a few reports available for the photocatalytic degradation of different BMWs. Therefore, the focus should be steered towards the photocatalytic degradation for the BMW management. Alkaline hydrolysis is another method where sodium hydroxide can be added to the steam disinfection system for the complete digestion of the BMWs. It is also found to be effective for destroying the prior wastes which are derived from different animals and contain transmissible spongiform encephalopathy like mad cow. The emergence of a hybrid system like a combination of chemical treatment and advanced steam sterilization coupled with shredding can effectively disinfect and decompose the BMWs. This hybrid system is potentially suitable for the treatment of biological wastes like pathological waste, anatomical parts, etc.
All conventional techniques for the BMW treatment have multiple drawbacks in terms of energy and emissions. The new technologies have overcome the issues related to the drawbacks and shown more efficiency in the BMW management; however, their high-cost plant set up and operation make hindrance for the wider adoption. Therefore, more efforts and investments should be made available towards the optimization of these technologies. The government and industry partners should come forward to support the research related to the optimization and standardization of these processes. Summarizes the possible aspects of BMW management for overcoming challenges due to COVID-19 like pandemic in the future.
Effective segregation of the BMWs should be given top priority. Complete segregation at the entry points of BMWs can solve the 80% problems associated with the generation of the huge BMWs during any COVID-19 like pandemic. So there must be a shuffling of the standard handling of BMWs i.e. segregation at the entry points followed by collection instead of the existing system of the collection followed by segregation.
Health care facilities should conduct proper training and awareness programs for their employees at regular intervals.
The general public should have sound knowledge about the risks of hazardous/infectious BMWs and their effects upon being handled wrongly.
Training and regulations for the general public should be conducted as community instructions or learning co-curricular at schools that how to discard infectious or hazardous BMWs.
Regular inspections should be done by agencies like health administrations, pollution control boards, and environmental protection agencies.
Attendants/patients should be sufficiently instructed in a simple way to discard their wastes within the hospital campus.
Proper safety protocols should be followed by the workers involved in the sanitization and treatment departments while handling the BMWs in order to lessen the environmental hazard or infection spreading as well as their own safety.
New technology should be developed for the treatment of the flexible amount of BMWs, aiming at the unexpected spike of exploding diseases at a certain period of time just like the COVID-19 pandemic.
The management body of hospitals should oversee and audit all the policies from time to time as required by the situations and sometimes in a sudden crisis.
Coordination among hospitals, municipal authorities, treatment providers, and pollution control boards is always given higher priorities for the sustainable and ethical treatment of the BMWs.
The hospital authorities should take the responsibility of reducing BMW generation.
The daily generation rate of different types of BMWs increases due to the increase of patients as well as the additional guidelines set by the CPCB during the pandemic. India has adequate facilities for the treatment of the enlarged volume of BMWs, but 100% treatment could not be achieved due to the drawbacks of certain policies and guidelines. Segregation of BMWs at the points of entry is very important as a major portion of the BMWs are non-hazardous in nature. Effective segregation can reduce the overall BMW management dramatically. Different conventional treatments techniques have been adopted by different health care facilities worldwide. Still, some techniques need urgent upgradation in order to overcome the disadvantages associated with them. Furthermore, intensive research is required for the development of valuable products from the BMWs. Similarly different new techniques like plasma pyrolysis, sharp/needle blaster technology, PIWS-3000 technology, microwave treatment, alkaline hydrolysis, steam sterilization, and biological treatment should be adopted by sanctioning required funding from the government and the industries partners. Further, some policies should be re-evaluated as the treatment and disposal methods of BMWs adopted by the health care facilities or municipal authorities depend upon numerous parameters like types of wastes, the volume of waste generated daily, the proximity of treatment site to waste source, topological challenges, availability of treatment plants and competent human resources.
Dr.Javeed Kakroo Microbiologist Certified infection control Auditor Kidney Hospital Srinagar [email protected]