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ORIGINAL RESEARCH  
Year : 2011  |  Volume : 22  |  Issue : 3  |  Page : 371-375
Dental perspective on biomedical waste and mercury management: A knowledge, attitude, and practice survey


1 Associate Professor, Department of Conservative Dentistry and Endodontics, Sudha Rustagi College of Dental Sciences and Research, Faridabad, India
2 Prosthodontist, Private Practice, New Delhi, India

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Date of Submission18-Dec-2009
Date of Decision22-Oct-2010
Date of Acceptance24-Dec-2010
Date of Web Publication3-Nov-2011
 

   Abstract 

Context: Management of waste generated in any health-care facility is a critical issue as it poses a direct threat to human health as well as to the environment. The biomedical waste generated in the dental scenario includes sharps, used disposable items, infectious waste (blood-soaked cotton, gauze, etc.), hazardous waste (mercury, lead), and chemical waste (such as spent film developers, fixers, and disinfectants). A major concern in our field is management and disposal of mercury.
Aims: To obtain information about the knowledge, attitude, and practices of dental institutions and dental practitioners in the disposal of waste.
Settings and design: A self-administered questionnaire, composed of 50 questions was designed.
Materials and Methods: The questionnaire was distributed among the participants, chosen randomly, including dental students, faculty from dental colleges and private practitioners in and around Delhi, India.
Statistical analysis used: The percentage response for each question from all the participants was obtained and the data was calculated.
Results: Many dentists have knowledge about the waste management but they lack in the attitude and practice.
Conclusions: There is need for education regarding hazards associated with improper waste disposal at all levels of dental personnel. It is imperative that waste should be segregated and disposed off in a safe manner to protect the environment as well as human health.

Keywords: Biomedical waste, dental amalgam, hazardous waste, survey

How to cite this article:
Sood AG, Sood A. Dental perspective on biomedical waste and mercury management: A knowledge, attitude, and practice survey. Indian J Dent Res 2011;22:371-5

How to cite this URL:
Sood AG, Sood A. Dental perspective on biomedical waste and mercury management: A knowledge, attitude, and practice survey. Indian J Dent Res [serial online] 2011 [cited 2019 Jul 18];22:371-5. Available from: http://www.ijdr.in/text.asp?2011/22/3/371/87055
The term biomedical waste has been defined as "any waste that is generated during the diagnosis, treatment, or immunization of human beings or animals, or in the research activities pertaining to or in the production or testing of biological and includes categories mentioned in schedule I of the Biomedical Waste (Management and Handling) rules 1998." [1],[2] According to WHO, SEARO, the 11 South-East Asian countries together produce some 350 000 tons of health care waste per year, close to 1000 tons a day which is both hazardous and nonhazardous. [3] The concern for biomedical waste management has been felt globally with the rise in deadly infections such as AIDS, Hepatitis-B due to indiscriminate disposal of health-care waste. As it is not managed properly, most of it is considered hazardous despite the fact that only 10-20% is infectious in nature. [4]

biomedical waste includes waste generated from research and teaching labs or laboratory animal facilities and consists of the following.
  • Anatomical waste (human and animal anatomical waste, tissues, organs, body parts, body fluids, blood, and sera).
  • Nonanatomical waste.

    • Used products or equipment contaminated with microorganisms or recombinants, mutants, or hybrids hereof.
    • Live or attenuated vaccines that have not been deactivated.
    • Contaminated animal bedding (i.e., from experimental animals that have been infected with infectious material).
    • Clinical materials consisting of needles, syringes, surgical blades, and clinical glass capable of causing punctures or cuts.


All anatomical waste is potentially infectious and considered hazardous.

The non-anatomical waste can be infectious (such as microbiology lab waste or disposables contaminated with a causative agent or non-infectious (such as disposable gloves, bench covering, and clinical equipment). [5]

Dental offices generate a number of hazardous wastes that can be detrimental to the environment if not properly managed. This includes sharps, used disposable items, infectious waste (blood-soaked cotton, gauze, etc.), mercury containing waste (mercury, amalgam scrap), lead containing waste (lead foil packets, lead aprons), and chemical waste (such as spent film developers, fixers, and disinfectants). Studies have shown that wastewater from dental offices typically contains elevated concentrations of metals such as mercury, silver, copper, tin, and zinc. Sources of these metals include placement and removal of amalgam fillings (mercury, silver, copper, tin, and zinc) and disposal of the spent x-ray fixer solution (silver). [6]

The biomedical waste management and handling rules have been notified in 1998. The rules were amended twice in 2000, primarily to address administrative matters. The rule makes it mandatory for the health care establishments to segregate, disinfect, and dispose their waste in an ecofriendly manner. An important prerequisite and key to successful waste management program is segregation which is the separation of different types of waste as per treatment and disposal option. Segregation and collection of various categories of waste should be done at source, in separate containers so that each category is treated in a suitable manner to render it harmless. For waste management to be effective, the waste should be managed at every step, from acquisition to disposal. [2],[7]

Some survey studies have been done in medical hospitals which have discussed the waste management scenario in hospitals. [8],[9],[10] Very few survey studies have been conducted in dental health care to see the awareness . A study conducted in New Delhi, India, amongst the 64 dentists, which form the teaching staff in a government institution, reported that the majority of the respondents were not aware of proper clinical waste management. [10],[11] Another study conducted in Bangalore, India, among private dental practitioners conducted that the majority of the dentists were not practicing proper methods of health-care waste disposal. [12]

A large amount of literature has been reviewed regarding proper waste management. [13],[14],[15],[16]

Aims and objectives

  • To obtain information about the knowledge, attitude, and practices of dental institutions and dental practitioners in the disposal of waste.
  • Discuss the best management practices in relation to the findings of survey.



   Materials and Methods Top


  • A self-administered questionnaire was designed and distributed among 100 dentists, who included dental students, faculty working in the dental institute, and private practitioners. The survey form was composed of 50 questions framed based on knowledge, attitude, and those regarding the practice of dentists in relation to dental health-care waste management.
  • The questionnaire was given in three dental teaching institutes and to private practitioners in and around Delhi, India. Confidentiality of the participants was maintained.
  • The percentage response for each question from all the participants was obtained and the data was calculated.



   Results Top


Among the participants, 63% were males and 37% were females aged between 22 to 55 years. Forty-seven percent were teaching in a dental institute, 23% were dental students, and 30% were private practitioners. Fifty-three percent had completed postgraduation and 47% were graduates. Fifty-eight percent dentist's experience was of less than 5 years, 30% had 5-10 years of experience, 9% had 10-15 years of experience and 3% were having experience of more than 15 years.

Sixty percent of the respondents were of the opinion that all health care waste is hazardous and all respondents agreed that exposure to hazardous health care waste can result in disease or infection. In our study, only 75% of the participants were aware of biomedical waste BMW(management and handling) regulations applicable to dentists. All respondents agree that waste should be segregated into different categories but only 67% followed the rules. Only 68% clinic and hospital were having tie up with waste management companies, and rest 32% were disposing all kind of waste into general garbage. Thirty-four percent dentists had an opinion that any plastic bag can be used for waste disposal. In this survey, only 32% of dentists were using red bags to throw plastic such as gloves and rubber dam. Remaining were disposing in yellow bag, and 13% had the opinion that they should be thrown in a puncture proof container. Thirty-six percent participants were using yellow bag for disposal of blood-soaked cotton or gauze. In the survey, it was found that 67% of the participants were disposing the pharmaceuticals into regular waste.

Twenty-one percent of the dentists were disposing the sharps in, yellow, red, or black bag.

Only 50% the dentists were using amalgam routinely in their practice and 71% preferred composite material instead of amalgam for restoration. The study showed that patients are increasingly coming for removal of old amalgam restoration for esthetic purpose. Forty-two percent of the dentists recommend replacement of an old amalgam restoration with the composite.

In our study, 55% of the respondents use amalgamator to mix amalgam, 33% mix manually, whereas 12% are not using amalgam at all. Thirty-six percent use pre-encapsulated amalgam and 60% place bulk mercury in the amalgamator. In this survey, 6% were disposing mercury into the drain, 39% into the dustbin, and 42% were storing the excess mercury in glycerin and water.

Sixteen percent of the respondents were manipulating amalgam with ungloved hands. Sixty-nine do not use rubber dam while placing or removing amalgam restorations and 26% do not use high-vacuum suction while handling amalgam in mouth. Thirty-six percent of dentists were using cotton to hold excess Hg spilled on the floor, and 42% use stiff paper to pick it. Forty-seven percent of the dentists were aware of amalgam separators and only 10% participants had separator installed at their workplace. Forty-five percent respondents throw spent or amalgam capsules in general waste. Only 24% of the dentists were disposing off unused amalgam or scarp into the separate container, 54% were disposing into general waste and rest into red, yellow, or black bag. Twenty-three percent of the participants were placing cotton contaminated with amalgam particles into separate container and rest were disposing along with general waste or into red, yellow, or black bag. Forty-five percent of the dentists clean the suction unit once in a week, 36% once a day, 9% once a month, and 10% never clean the suction. In this survey, it was found that 30% dentists were using conventional radiography, and 47% were using both conventional and digital. Forty-one percent of the dentists using conventional technique were discarding lead foils into the general garbage and 36% were collecting them in a separate container. Thirty-four percent of dentists in our survey were draining the fixer into the washbasin, 60% were of the opinion that waste developer can be flushed down the drain, and 25% were of the view that spent developer and fixer solutions be mixed and flushed into the drain. In this survey, 66% of the participants were using disinfectants for cold sterilization, out of wh ich 72% were flushing them into drain.

Our data revealed that only 22% of the camp organizers were managing the waste protocol. Almost all the respondents felt that waste management program should be part of curriculum during graduation and would like to attend a program on hospital waste management.


   Discussion Top


The questionnaire study was chosen as it allows us to collect lot of information and data from a large number of respondents relatively quickly. [11] The participants were chosen randomly from three dental institutes and private practitioners in the NCR region, India. Approximately 23% of respondents were working in the institute as well as having their own practice. Therefore, one limitation of the study was that, they may be following the guidelines of waste management protocol at one work place and may not at the other. Hence, the actual practice in management of waste may not have been obtained. Results showed improper waste management in many aspects. The results are similar with the previous survey studies. [11],[12]

According to WHO, hospital waste produces 80-85% of non-hazardous waste and 15-20% of hazardous waste. The hazardous waste can be infectious (10%) like sharps or non-infectious (5%) such as chemical and pharmaceutical waste. [4]

Collection of biomedical waste should be done as per BMW (management and handling rules, 1998) rule 6, Schedule II and the containers/bags should be labeled as per guidelines of schedule III, i.e, biohazard and cytotoxic symbol. [2],[17]

Another important issue is the types of plastic bags used for collection of waste. The plastic bags used for waste disposal are special non-chlorinated, which can be incinerated. Normal plastic bags if used, will release dioxins and furans which further pollute the environment.

According to BMW (management and handling rules, 1998, [2],[17] Schedule I)

  • all the items sent to incinerator/burial, should be placed in yellow color bags, e.g., human anatomical waste, microbiological waste, and soiled plastic waste;
  • all the biomedical waste to be sent for microwave/autoclave/chemical treatment should be placed in red colored bags, e.g., infected plastic syringes, tubings, gloves, rubber dam sheets;
  • any waste which is sent to shredder after autoclaving/microwaving/chemical treatment is to be placed in blue/white translucent bags/containers, e.g., sharp containers for needles and used files.


Schedule I and II of biomedical waste (management and handling rulings) 1998 (Adapted from national guidelines on hospital waste management) [Table 1]. [2]
Table 1: Schedule I and II of biomedical waste (management and handling rulings) 1998

Click here to view


According to national guidelines of BMW rulings, [2] 48 hours is the maximum time limit for which biomedical waste can be kept before transporting to common waste treatment facility.

Pharmaceutical waste that includes expired drugs should also be disposed off properly. Such waste is considered to be hazardous non-infectious waste. Either it should be returned to manufacturer or collected in a separate black bag and given to waste collection company, where they are either buried in deep landfills or incinerated. [16],[17]

Needle stick and puncture wound injuries and resulting infections have been recorded in situations where sharps have been improperly handled and/or disposed. The sharps (needles, scalpel blades) are that category of waste that needs maximum precaution and care. The needles, which comprise of the bulk of "sharps" should be destroyed by needle destroyers or by using syringe melting and disposal system. The mutilated sharps should be placed in puncture proof sharp container containing 1% NaOCl for disinfection. Once the container is three-fourth filled, it should be given to waste handlers and sent for shredding, encapsulation, and disposal in landfills by common treatment facility. [2],[6],[18]

The main issue of concern in a dental practice is management of mercury. Silver amalgam has been used as dental restorative material for more than 150 years. Even today, with the advent of new synthetic non-metallic materials and novel, time-saving procedures, silver amalgam is the most widely used and costeffective dental material in restorative dentistry.

Mercury containing waste can be in form of elemental mercury or scrap amalgam. (Contact or noncontact amalgam scrap.) [19]

Contact amalgam is amalgam that has been in contact with the patient, e.g., extracted teeth with amalgam restorations, carving scrap collected at chair-side, and amalgam captured by chair- side traps, filters, or screens. Non-contact amalgam is amalgam that has not been in contact with the patient, e.g., excess unused set amalgam, amalgam capsules.

Both the contact and non-contact amalgam should be stored separately in different containers. The containers should be labeled with a "biohazard" symbol. As recommended by American Dental Association guidelines should be followed for proper disposal of amalgam waste. [19],[20],[21]

Placement and removal of dental amalgam restorations generate amalgam waste particles that are suctioned into vacuum line and discharge into sewer system. Chair side traps and vacuum pump filters generally remove 40-80% of the amalgam particles from the wastewater stream; however, some amalgam particles still enter into the sewer system. Amalgam separators are devices designed to remove amalgam waste particles completely in dental office discharge. [22],[23] These separators remove the particles using different techniques such as sedimentation, filtration, centrifugation, or ion exchange. According to ADA, mercury and silver that is present in amalgam wastes should be recovered through a distillation process and sent for recycling.

Amalgam that is rinsed down the drain may be released directly to a waterway, or released into the air, or into the soil. When the amalgam scrap is discarded along with the regular trash or along with the waste to be incinerated (yellow bag), mercury releases into the air or leaches into the groundwater.

In addition to dental amalgam, the most common source of regulated heavy metals in the office is lead from lead foil and lead shields. [16] It is very important to manage the waste generated during developing of radiographs. Lead cannot be placed in the regular solid waste containers nor can it be disposed of down the drain; it must be managed as either recyclable metal or hazardous waste. Lead is toxic and can contaminate soil and groundwater if it ends up in landfill sites. Lead foils should be collected in separate container and given back to the manufacturer or waste vendor for recycling of silver. X-ray photo chemicals (developer, fixer, and cleaning solutions) used for processing the radiographs also contain heavy metals. The used fixer should be collected separately in a labeled plastic container. Silver from used fixer is a valuable source and should be recycled. It should not be discarded down the drain. Waste developer can be flushed into the drain because the hydroquinone is consumed during processing and becomes nonhazardous. In no case should the spent developer and fixer solutions be mixed and drained.

Another hazardous waste is chemicals, disinfecting agents. [16] Dental offices use a variety of chemicals for sterilization, disinfecting, and cleaning. Several of these products may contain active chemical ingredients (e.g., formaldehyde), that may be classified as hazardous. Local municipality should be consulted, before discharging chemicals into the sewer system, if pH of chemical is less than 2 and higher than 12, if it contains higher concentration of formaldehyde or ignitable substances like (alcohols, ether, acetone, xylol, chloroform). It should be remembered that waste water eventually is reused as local drinking water.

All these aspects require and necessitate more awareness and training in infection control and BMW management for both dental and nondental personnel. It is recommended that this important facet should be included in curriculum of undergraduate and postgraduate dental academics and also should be mandatory for dental hygienist, dental technicians, and dental operating room assistant. The rule applies to all those persons who generate, collect, receive, store, transport, treat, dispose, and handle the biomedical waste. It is ideal and desirable that occupational safety be a prime consideration for any system of waste management.


   Conclusion Top


It can be concluded from this survey study that, though many dentists have knowledge about the management of waste but are not practicing diligently. Legislations to regulate are not very stringent, awareness is low and there is laxity in execution of correct practices. It is imperative that waste should be segregated and disposed off in a safe manner to protect the environment as well as human health. The rule applies to all those persons who generate, collect, receive, store, transport, treat, dispose, and handle the biomedical waste. Regular monitoring and training is required at all levels. There is need for education regarding hazards associated with improper waste disposal. It is highly recommended that waste management program should be a part of academic curriculum and continuing dental education.


   Acknowledgment Top


I acknowledge all the respondent dentists for participating in the survey study.

 
   References Top

1.Govt.of India, "Bio-medical waste (management and handling) rules". The gazette of India. Ministry of Environment and Forest. 1998.  Back to cited text no. 1
    
2.National guidelines on Hospital waste management. Biomedical waste regulations. 1998.  Back to cited text no. 2
    
3.Survey of Hospital waste management in SEA region. WHO: Health situation in the South -East Asia Region, 1998-2000: 1999. p. 1-34.  Back to cited text no. 3
    
4.Manual for control of hospital associated infections. Standard operative procedures. National AIDS control organization; 1999. p. 50-66.  Back to cited text no. 4
    
5.Environmental health and safety. Available from: www.unb.ca/safety/biosafety.html. [last accessed on 2009 Dec 03].  Back to cited text no. 5
    
6.Environmental regulations and best management practices; Available from: http://www.crd.bc.ca. [last accessed on 2009 Dec 03].  Back to cited text no. 6
    
7.CPCB. Manual on Hospital Waste Management. Delhi: Central Pollution Control Board; 2000.  Back to cited text no. 7
    
8.Saini RS, Dadhwal PJ. Clinical waste management: A case study. J Indian Assoc Environ Manage 1995;22:172-4.  Back to cited text no. 8
    
9.Patil AD, Shekdar AV. Health care waste management in India. J Environ Manage. 2001;63:211-20.  Back to cited text no. 9
    
10.Kedar R, Deshpende A. Critical evaluation of Biomedical Waste Management practices in Kathmandu valley. Chennai, India: Proceedings of the International Conference on Sustainable Solid Waste Management, 2007. p. 142-7.  Back to cited text no. 10
    
11.Kishore J, Goel P, Sagar B, Joshi TK. Awareness about biomedical waste management and infection control among dentists of a teaching hospital in New Delhi. J Indian Dent Res 2004;11:157-61.  Back to cited text no. 11
    
12.Sudhakar V, Chandrashekar J. Health care waste disposal among private dental practices in Bangalore City, India. Int Dent J 2008;58:51-4.  Back to cited text no. 12
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13.Bekir Onursal. Health care waste management in India. Lessons from experience. Oct 2003  Back to cited text no. 13
    
14.Hedge V, Kulkarni RD. Biomedical waste management. J Oral Maxillofac Pathol 2007;11:5-9.  Back to cited text no. 14
    
15.Toxics Link: "Understanding and Simplifying bio-medical waste Management: A Training Manual for Trainers", New Delhi; 2005. Available from: http://www.toxicslink.org. [last accessed on 2009 Dec 03].  Back to cited text no. 15
    
16.Best management practice for waste disposal. Available from: http//www.ida.in/Biomedical Waste Protocol/classificationtypesofwaste.htm/. [last accessed on 2009 Dec 03].  Back to cited text no. 16
    
17.Block 2 Health care Waste: Definitions; BHM-001 Fundamentals: Environment and Health, Health Care Waste Management regulations., School of Health Sciences IGNOU.  Back to cited text no. 17
    
18.Management of sharps. Available from: http://ww3.5ho.int/injecion_safety/en/. [last accessed on 2009 Dec 03].  Back to cited text no. 18
    
19.Best Management Practices for Amalgam Waste. ADA, Oct 2007. Available from: http://www.ada.org. [last accessed on 2009 Dec 03].  Back to cited text no. 19
    
20.Dental Mercury Hygiene Recommendations. J Am Dent Assoc 1999;130:1121-3.  Back to cited text no. 20
    
21.Dental Mercury Hygiene Recommendations. J Am Dent Assoc 2003;134:1498-99.  Back to cited text no. 21
    
22.Mcmanus KR. Purchasing, installing and operating dental amalgam separators. J Am Dent Assoc 2003;134:1054-65.  Back to cited text no. 22
    
23.Jokstad A, Fan PL. Amalgam waste management. Int Endod J 2006;56:147-58.  Back to cited text no. 23
    

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Correspondence Address:
Ashima Garg Sood
Associate Professor, Department of Conservative Dentistry and Endodontics, Sudha Rustagi College of Dental Sciences and Research, Faridabad
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0970-9290.87055

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