|Year : 2013 | Volume
| Issue : 3 | Page : 235-240
A simplified model for biomedical waste management in dental practices - A pilot project at Thane, India
Om N Baghele1, Subodh Phadke2, Ashish A Deshpande2, Jayant P Deshpande2, Mangala O Baghele3
1 Department of Periodontology and Public Health Dentistry, SMBT Dental College and Hospital, Sangamner, Maharashtra, India
2 Officials, Indian Dental Association, Maharashtra State Branch; Private Dental Practice, Thane, Maharashtra, India
3 Private Dental Practice, Thane, Maharashtra, India
|Date of Web Publication||5-Aug-2013|
Om N Baghele
Department of Periodontology and Public Health Dentistry, SMBT Dental College and Hospital, Sangamner, Ahmednagar - 422 608, Maharashtra
Source of Support: None, Conflict of Interest: None
A lot of biomedical waste (BMW) is generated in dental practices, which can be hazardous to the environment as well as to those who come in contact with the materials, if not dealt with appropriately. Most of the rules world-wide are not specific for dental BMW management and hinder easy understanding by dental practitioners. Because of lack of clear-cut guidelines either from Dental Council of India or Government of India or Indian Dental Association (IDA) on disposal of dental wastes, this article is designed to explore and review on these issues and formulate a simplified scheme. The guidelines by the Maharashtra Pollution Control Board from the directives of The Ministry of Environment and Forests, Government of India through BMW (Management and Handling) Rules, 1998, (BMW-MH-98), similar guidelines being followed elsewhere in the world, the local BMW disposal company's rules and the IDA's Clinic Standardization Program guidelines. We developed and implemented a simplified waste segregation protocol for practicing dentists and dental hospitals. A methodological dental waste segregation protocol was required considering its disposal and ill-effects on health and the environment. The simplified scheme provided a good model to be followed in developing countries like India. The scheme improved understanding among dentists because of its self-explanatory nature.
Keywords: Biomedical waste, dental waste, new model, waste management
|How to cite this article:|
Baghele ON, Phadke S, Deshpande AA, Deshpande JP, Baghele MO. A simplified model for biomedical waste management in dental practices - A pilot project at Thane, India. Eur J Gen Dent 2013;2:235-40
|How to cite this URL:|
Baghele ON, Phadke S, Deshpande AA, Deshpande JP, Baghele MO. A simplified model for biomedical waste management in dental practices - A pilot project at Thane, India. Eur J Gen Dent [serial online] 2013 [cited 2019 Sep 17];2:235-40. Available from: http://www.ejgd.org/text.asp?2013/2/3/235/115992
| Introduction|| |
According to the Notification by the Ministry of Environment and Forests, Government of India; "biomedical waste (BMW)" means any waste, which is generated during the diagnosis, treatment or immunization of human beings or animals or in research activities pertaining thereto or in the production or testing of biologicals, and including categories mentioned in Schedule I [Table 1]; and the "Occupier" in relation to any institution generating BMW, which includes a hospital, nursing home, clinic, dispensary, veterinary institution, animal house, pathological laboratory, blood bank by whatever name called, means a person who has control over that institution and/or its premises. It further mentions that it shall be the duty of every occupier of an institution generating BMW to take all steps to ensure that such waste is handled without any adverse effect to human health and the environment.  By these definitions, Dentist is the occupier of a clinic who generates BMW and should be responsible for its overall handling.
Inadequate and inappropriate handling of dental health-care waste may have serious public health consequences and a significant impact on the environment, considering the increasing number of dentists in urban areas and increased awareness about the dental treatment amongst the public. The total dental care waste produced throughout metros, e.g. Mumbai - Navi Mumbai Thane (India) belt, may not be in any way insignificant. To our modest estimation, an average running dental clinic may produce around 0.5-1.0 Kg of waste per day. The waste generated by around 4500 dentists practicing in and in the vicinity of Mumbai might be substantial. Appropriate management of dental care waste is thus a crucial component of environmental health protection and it should become an integral feature of dental services. The handling of BMW is mentioned in Schedule II [Table 1] of the BMW-MH-98 Rules.
| Classification of Health-Care Bmw|| |
Several classifications of health-care waste have been put forward. One such classification divides hospital waste into hazardous and non-hazardous.  There are various categories of hospital waste, but some are important for dental care workers. Waste categories and description as suggested by World Health Organization,  is given in [Table 2].
| Health Hazards of Dental Care Wastes|| |
Because the BMW contains infectious agents, toxic or hazardous chemicals or pharmaceuticals, sharps and it may be genotoxic or radioactive; it is potentially risky for persons who are exposed to it. There are health risks to several different and overlapping populations, e.g. health-care employees, dentists, patients, waste handling and treatment workers, and the general population.
The waste, if allowed to accumulate, is a health hazard, because: It decomposes and favors fly breeding, it attracts rodents and vermin, the pathogens, which may be present in the waste may be conveyed back to man's food through flies and dust, there is a possibility of water and soil pollution and heaps of refuse present an unsightly appearance and nuisance from bad odors. 
- Hazards from infectious waste and sharps:  Pathogens in infectious waste may enter the human body through a puncture, abrasion or cut in the skin, through mucous membranes by inhalation or by ingestion. There is a particular concern about infection with Human immunodeficiency virus and hepatitis virus B and C, for which there is a strong evidence of transmission via health-care waste. Bacteria resistant to antibiotics and chemical disinfectants may also contribute to the hazards created by poorly managed waste
- Hazards from chemical and pharmaceutical waste:  Many of the chemicals are toxic, genotoxic, corrosive, flammable, reactive, explosive or shock sensitive. Although present in small quantity they may cause intoxication, either by acute or chronic exposure and injuries, including burns. Disinfectants are particularly important. They are used in large quantities and are often corrosive and reactive chemicals may form highly toxic secondary compounds
- Hazards from genotoxic waste:  The main pathway of exposure is inhalation of dust or aerosols, absorption through the skin, ingestion of food accidentally contaminated with cytotoxic drugs, chemicals or other waste
- Hazards from radioactive waste:  It is genotoxic and thus may affect genetic material. The effects of exposure can range from headache, dizziness, and vomiting to malignancies
- Public sensitivity: Apart from health hazards, the general public is very sensitive to visual impact of health-care waste particularly anatomical waste.  There can be esthetic degradation of the surroundings from the careless disposal
- Environmental issues: There can be several adverse environmental impacts from inappropriate handling of waste. It may lead to changes in microbial ecology and microbial resistance to several anti-microbial agents.
Mercury in the environment
Mercury is a naturally occurring metal; however, about half of the mercury released to the environment comes from human activity. Of that amount, 53% is emitted from combustion of fuels for energy production and 34% is from the combustion of waste. Sources associated with manufacturers and consumers make up the remaining 13%, with dentistry contributing less than 1%. Dentists world-wide consume 3-4% of all the mercury produced. The mercury in dental amalgam can be released to the environment through various media (air, water, solid waste). Mercury is a persistent and deadly contaminant in the water environment. Metallic mercury such as that used in amalgam is relatively non-toxic. However, when mercury is released to the environment, some portion may be converted by bacteria to methyl mercury, a potent neurotoxin. Methyl mercury biomagnifies in the food chain such that levels of methyl mercury are created that are tens of thousands of times higher in some predatory fish than in the surrounding waters. The Federal Food and Drug Administration, USA has determined that any level of methyl mercury in fish above 1 mg/l is unsafe. Mercury is bio-accumulative, which means that it can build up in fish and cause health problems in humans and other animals that eat fish. Some mercury released into the air (when dental wastes that contain amalgam are incinerated, some of mercury in the fillings of removed teeth or scraps of amalgam in the waste) eventually collects in the waterways, where it enters the food chain. As a precautionary measure, one should assume that all or most of the mercury released into the air or surface water may accumulate in fish. 
In an interesting study in Finland,  the National Public Health Institute projected level of mercury in wastewater as related with levels of mercury in stimulated saliva and amalgam filled teeth. The mercury limit for sewage is 0.05 mg/l (=250 nmol/l) effluent, according to the European norms. The risk of exceeding the limit increased 2-fold for every 10 additional amalgam-filled surfaces. These results demonstrate that humans, especially in populated areas, can be a significant source of mercury pollutants. As a consequence of mercury release, bacteria may acquire mercury resistance as well as resistance to other antimicrobial agents; thus, resulting in failure of antibiotic treatment.
Mercury in the clinic environment
Mercury forms vapors at room temperature,  and also particles of amalgam fillings and mercury vapor from old amalgams forms an aerosol that is projected into the clinic atmosphere.  The threshold limit value of mercury in air is 0.05 mg/m 3 of air. It is the vapor level to which the average worker can be safely exposed for 8 h a day and 5 days/week. The current standard for mercury is 0.1 mg/m 3 of air averaged over an 8 h work shift.  Mercury can produce a toxic effect if sufficient amounts are absorbed through the skin, lungs or gastro-intestinal tract. Most common route is through lungs by inhalation of the vapor. 
Silver, in the form of silver thiosulfate, is found in high concentrations in fixer solutions and rinses from X-rays. Light-sensitive silver-halide crystals present on the X-ray film are released as silver thiosulfate during the fixing process. Used X-ray fixer is regulated as a hazardous waste because of the high silver content. In the environment, free-ionic silver acts as an enzyme inhibitor by interfering with the metabolic processes of organisms.
Lead is used in the foil that shields X-ray film. Lead is a heavy metal that affects neurological development and functions and can potentially leach from landfills into the environment.
| Discussion and Management of Dental Care Wastes|| |
The management of health-care wastes involves active participation and co-ordination between governmental and non-governmental bodies, the bureaucracy and the health care personnel. In developing nations strong political will and requisite infrastructure may be lacking for appropriate management of BMW. The BMW disposal in India is dismal and that too about dental waste disposal is in nascent stages. Most standalone healthcare centers, including dental clinics, don't recognize the need for proper BMW disposal.
In a recent study,  on 432 private dentists in Bangalore city, 64.3% do not segregate waste before disposal and 47.6% hand over health-care waste to street garbage collectors; 42.1% felt that there was a lack of waste management agency services and 16.9% felt that a lack of knowledge were the main hurdles. They concluded that, a large proportion of the dentists are not practicing proper methods of health-care waste disposal and many require improvement in their knowledge. Similar reports and lack of seriousness has been reported throughout the world (Greece,  Palestine,  Italy,  Bangkok,  Sweden,  etc.). One more study by Kishore et al.  at New Delhi reiterated the need for dentists to be educated in BMW management.
We should take utmost care of BMW, even-though, the risk of transmitting infectious diseases through BMW is low because of the unlikelihood of survival of the infectious agent in refuse environments and the low probability of a portal of entry for infectious organisms in a susceptible host.  In multiple studies, household waste has been found to contain more microorganisms with pathogenic potential for humans on average than medical waste. , The only medical waste that has been associated with infectious disease transmission is contaminated sharps (needles, scalpels, or lancets). 
Dental offices generate a very small amount of silver waste relative to other photographic processing facilities. A batch-replenished processing of 450 size 2 dental films and eight 35 mm film strips, each 250 mm long, yields 830 ml of used fixer solution with a silver concentration of 10.90 g/l. Silver concentrations in used fixer solutions generally range from 8 g/l to 12 g/l. Silver in used fixer solutions is in the form of silver thiosulfate complexes, which are extremely stable and have very low dissociation constants. There is virtually no free silver ion (Ag+) in used fixer solutions. The effect of silver on aquatic life depends on the form of silver. In one aquatic life toxicity study using fathead minnows, silver thiosulfate was more than 17,500 times less toxic and silver sulfide was more than 15,000 times less toxic than free silver ion (Ag+). It is generally accepted that silver in used fixer solutions has little, if any, adverse environmental effect.  Use of an in-office silver recovery unit (e.g. Kodak Chemical Recovery Cartridge, Eastman Kodak, Rochester, N.Y.) to remove silver from used fixer solutions can be an effective method.
The dental waste of utmost importance is related to mercury and mercury-related products. Various precautions should be exercised while purchasing, storing, handling and disposal of these products. Mercury in various forms is found in clinic air, chair tubing, clinic plumbing, suction traps, and filters, etc. Appropriate guidelines on various aspects have been given by the American Dental Association. ,,,,,,
A scheme outlining various steps involved in managing BMW is modified from Rutala et al. and American Medical Association  for dental BMW and is presented in [Table 3]. Based on the above discussion we devised a simple, clear, cost-efficient, effective and implementable dental BMW disposal program considering local requirements in mind [Table 4]. The scheme was outlined to the dentists of Thane region, few workshops were held by the Indian Dental Association (IDA) and the waste segregation system's pamphlets [Table 4] were distributed. This scheme was then followed by around 200 dentists associated with the Thane Branch of IDA with good response and success since last 3.5 years.
|Table 3: Various components of a bio-medical dental waste management protocol (modified from Rutala et al. and American Medical Association)|
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|Table 4: The proposed simplified biomedical waste segregation scheme for dental clinics|
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| Conclusion|| |
As we, the dentists are an educated lot, aware of the biology and environments and respected citizens; we do have some responsibility toward our surroundings and descendents. The way we dispose of waste affects the quality of the environment that we pass on to our children and their children. If we reap short term benefits from cheap disposal of wastes in the air, land, fresh water, seas or even outer space, we may pass on staggering costs on to future generations, which must either try to cleanse the disposal sites or abandon them altogether.
The authoritative bodies in India and other developing nations should strictly implement and monitor BMW management according to their requirements in a systematic and simplistic manner. The governmental bodies should take responsibility of making these services available to the practicing dentists as well as dental hospitals.
| Acknowledgments|| |
We would like to thank the officials of Indian Dental Association, namely Dr. Ashok Dhobley, Dr. Ajit Oak and Dr. Rajesh Iyer, for their intellectual inputs. We would also like to thank Enviro-Vigil, an NGO, working in consultation with Government of Maharashtra, for their inputs on BMW; especially Prof. Vidhyadhar Walawalkar and Mr. Shriram Datar.
Clinical relevance to general dentistry
- Dental practices/hospitals produce a lot of biomedical waste (BMW)
- There are no specific guidelines for management of BMW in dental settings
- The nature of BMW generated in dental practices is somewhat different as compared to that of medical settings
- There is a grave need for educating dentists as well as access to BMW services
- This paper proposes a simplified model for waste segregation for general dental practitioners as well as specialists
- This scheme is in the fourth successful year followed by 200 dentists at Thane (Mumbai), India, which can be replicated elsewhere.
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[Table 1], [Table 2], [Table 3], [Table 4]