Assessment of Polymer based Material (PBM) Waste Production by clincal Dental Practices in Lahore, Pakistan; An Environmental Perspective

INTRODUCTION

Plastics have become integral to modern life, revolutionizing industries and enhancing convenience. Once hailed as a ground-breaking material, today, plastics pose a significant environmental threat that may result in a global crisis. Annual plastic production exceeds a staggering 400 million tons globally.¹

The exponential growth and widespread use of plastic across various sectors of life have led to plastic contamination  in ecosystems worldwide. Plastic contamination has become a global issue; scientists are measuring the number, type, and amount of plastic in the environment, tracking plastic generating hotspots, and monitoring trends.²

Healthcare professionals, too, contribute to plastic waste due to the extensive use of single-use plastic products.3 They rely on plastic-based disposables for hygiene and safety. From syringes to surgical instruments, plastics play a crucial role.4 Dentistry, with its reliance on synthetic polymers, is no exception.5 It, too, generates substantial plastic waste. Disposable items like gloves, masks, and packaging materials are essential for infection control but add to the environmental burden.5,6 Yet, the exact proportion of dental waste comprising plastics remains unquantified.

To address this gap, rigorous studies are necessary. Researchers must estimate the plastic content in dental waste, identify disposal patterns, and propose sustainable alternatives. Only through evidence-based assessments can we mitigate dentistry's plastic impact. Scientists diligently measure plastic  levels in the environment, track contamination hotspots, and monitor trends.7 There is a need to carry out studies to estimate the proportion of dental waste, including plastics.^5,8

The present study attempts to assess and quantify the solid waste of polymer material produced by an average private practicing dental clinic during a typical working day in Lahore. This data could be used by dental and environmental communities as baseline data.

METHODOLOGY

This study was conducted in Lahore, the capital city of the province of Punjab and the second most populous city in the country with over 10 million inhabitants. Lahore is divided into ten areas (nine towns and the cantonment area) and there are 637 private dental practices registered with the Pakistan Dental Association, Lahore Branch. These 637 practices were the study population. Sample size calculation was based on a study conducted by Bokhari et al., in 2009 9 which looked at Infection control methods in Lahore. In this study 94.35% of qualified dentists used gloves. This was taken as an estimated prevalence and the sample size was calculated to be 82.

 1.96= Z value for 95% confidence limit P= Estimated prevalence (0.9435 for 94.35%) d= Desired precision (0.05 for ±5%)

 It was a convenient sample study, a team of volunteers was sent to each town, and the first eight Pakistan Medical and Dental Council (PMDC) registered private dental surgeons in each town, who agreed to participate in the survey were included in the study and given the questionnaire to complete. One additional practice was included from Gulberg Town and Cantonment area as these two had the largest number of dental practices within their boundaries.

Data collection was conducted over 3 months from February to April 2024. The questionnaire was framed in two sets; demographic characteristics; and the range and number of PBM waste production. The answers to each question were numerically coded and were entered into the Microsoft Word Excel Sheet 2010 version. Frequency and percentage of data were analyzed while graphs were plotted by using Statistical Package for Social Sciences (SPSS) Inc. version 20 Chicago, USA (IBM Statistics Inc., Chicago, USA).

RESULTS

 General demographic characteristics of the dental professionals

 Out of 82 dental practices, 70 were solo practices, while 12 practices had two or more dentists working in them. A total of 101 dentists were involved in these 82 practices; however, the questionnaire was given to the principal/owner of the practice. Among the respondents 74 (90%) were male and only 8 (10%) were female, of which 50 (61%) had BDS as their terminal qualification while 39% had postgraduate qualifications. More than half of lead dentists (n=45; 54.9%) filling out the form had 10 years or less of dental practice experience, while only 2 (2.4%) had 31-35 years of practicing experience.

Patient

load Every private dental clinic had a differing volume of dental services rendered depending on the number of dental patients treated per day and the number of dentists working in each practice. An average of 9.5 patients were seen by a single dentist on each working day. A vast majority (78%) saw 10 or fewer patients and only 2 practices (3 & 4 dentist groups) had a patient load of 36-45 patients per day. The usage and disposal of PBMs are projected as per dentist rather than per practice.

 Polymer Based Material (PBM) waste production Polyethylene (PE), latex, polypropylene (PP), polyvinyl chloride (PVC), and styrene (PS) are five major types of polymers used in dental dentistry. Our results show that a total of 14,486 PBM pieces were produced per day by 101 practicing dentists. This can be translated to 143.4 pieces of PBM per dentist per day or 15 such pieces per patient. Out

 of which 47% were PE, 20% were Latex, 19% were polypropylene, 7% were PVC, and another 7% were PS. Percentage distribution of PBM disposables is shown in Figure 1

 Polyethylene (PE) as PBM disposables 

Collectively 6,710 polyethylene pieces were used per day by 101 dental practitioners in 82 practices as disposables for 959 patients. This converts to 66.43 PE pieces used by each dental practitioner and can be projected to be 18,607 PE pieces per practitioner per year based on 280 working days. The average consumption of PE as single-used disposables by each dental practice is shown in Table 1.

 Latex as PBMs disposables 

Latex or rubber as single disposable PBM waste is present in the form of rubber dams and gloves. In our survey, an average of 28 latex pieces were produced per day by a single dentist, in which 13 pairs of gloves (including gloves worn by dental assistants) and two rubber dams were consumed. The daily and annual consumption of an average  dental practitioner is shown in Table 2. 

 Polypropylene (PP) as PBM disposables 

 In this study, a total of 30 pieces of polypropylene were produced as single/multiple-used disposables per day by each dental practitioner converting to 8,440 pieces annually. It can be observed in Table 3 that the Face Masks and Instrument tray cover were not changed with every patient.

Polystyrene (PS) disposables

Our study reports an average of 9.5 disposable glasses/cups made up of polystyrene (PS) were used daily  or 2,660 annually. 

 Polyvinylchloride (PVC) disposables

Each dentist used an average of 9.5 PVC suction tips daily or 2,660 annually.

Clinical PBM waste produced by each dental practice

Collectively each dental practice produces 37,927 pieces of PBM per year.

Clinical PBM waste disposal by dental practices

Most dental practices (n=58 of 82; 70.7%) disposed of their clinical waste as municipal waste, while 28% (n=23) handed their daily PBM disposal waste to waste management companies, and one practice claimed to perform incineration. All waste management companies further discarded their collected waste by incineration so more than 29% of total daily dental disposables were collectively incinerated.

DISCUSSION

According to the World Health Organization, the private sector has become the primary provider of healthcare services having a 60-70% share in healthcare services in Pakistan.10 Dental practices in the country follow a similar trend. Small dental clinics may contribute significantly to oral healthcare delivery; however, their waste management system is not as secure as that of the large hospitals which can pose a serious threat to the environment.11

The present study reports that more than 70% of the PBM waste is mismanaged and disposed of as municipal waste, most of which ends up in landfills; this finding is consistent with the national figures where Pakistan generated an estimated 3.9 million tons of plastic waste in 2020, of which almost 70% was mismanaged.12

Our study recorded 17 different types of PBM in a waste bag from a dental clinic, this is similar to a British study which found an average of 25 different types of items in a typical clinical waste bag, of which more than 50% were PBMs.13 The plastic bags carrying this waste are part of the cause of 11.18% of environmental pollution worldwide14, in Pakistan, as many as 55 billion plastic bags are used per year.15 Our study showed that each dental practice uses 1750 plastic garbage bags annually. If we consider that the whole country has 10,000 dental practices on low estimates; this translates to almost 18 million plastic garbage bags annually.

Eco-Dentistry Association (EDA) estimates that more than 680 million chair barriers, light handle covers, and patient drapes worldwide are generated by dental offices.16 Our study estimates a national annual usage of 186 million pieces in Pakistan, this higher usage reflects the inclusion of 11 polythene-based disposable materials in our calculations  as opposed to only 3 in the EDA report. High usage of facemasks, polystyrene (PS) / Polyethylene Terephthalate (PET) based disposable glasses, and saliva tips are reported in our study, and a similar usage pattern has also been reported in the literature.8,16,17

An average clinical waste bag has been reported to weigh 6.72 kg. of which at least 3.5 kg. is that of PBMs.13 It is estimated that the 10,000 practices in Pakistan produce 9,800 tons of PBM waste each year, contributing to the 3.9 million tons of plastic waste produced by the country.12

All disposable items considered essential for cross infection control in dentistry, in discarded form, affect the environment negatively as polymer waste.13 Polymer pollution is classified as a universal threat.8,13,14 and the necessity to protect the environment from the ill effects of plastics is well-recognized.14

PVC is usually called poison plastic.18 While, the manufacturing of Styrofoam cups contributes to Pantene emissions, plastic cups release Chlorofluorocarbons (CFC) into the air.20 Styrene is also released into the water via plastic cups with both Pantene and styrene being hazardous to the environment and health. American Medical Association (AMA) has recommended that hospital authorities and physicians find alternatives to products made from PVC because it is a non-degradable and non-recyclable plastic.19 Waste disposal plays a pivotal role in reducing environmental and health hazards. A recent study showed that a large number of dental clinics did not dispose of their clinical waste properly21, which is similar to our findings.

Although, individual practicing dentists may create only a small quantity of environmentally hazardous waste; however, the accumulated waste produced by the dental profession may have a notable impact on the environmental footprint. Further studies are needed to assess the environmental impact of dental hospitals and the calculation of the carbon footprint created by the dental profession. Changing the behavior and attitude of dental professionals in society will have a significant impact in the reduction of polymer-based material (PBM) pollution.5,8,16,17

 CONFLICT OF INTEREST 

 None to declare 

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