This refers to the letter by Dr. Mahmood A. Khwaja, ‘Mercury: safe dental practice’ (Oct 20). We know that mercury amalgam is the oldest filling material used in the field of dentistry due to its cost effectiveness.
According to an early report, in clinics of Karachi, 57pc dentists use the hand-mixing method for the dispensing of mercury.
For the disposal of mercury amalgam waste, 55pc dentists use the sink and 25pc use bins in their dental clinics. This is most alarming as such toxic mercury/mercury waste disposal results in high mercury contamination of indoor air, as is evident from the reported recent field study/survey by the Sustainable Development Policy Institute (SDPI) team at 34 dental sites in some of the main cities of the country. Hazardous mercury exposure puts workers and public health in general, and children in particular, to a very high risk.
There is a need to create awareness among dentists and dental teaching institutions to follow the international criteria for the use and disposal of mercury amalgam so as to minimise mercury releases, emissions and exposure. It is strongly recommended that students at teaching institutions and dentists at clinics use capsulated alloys for dental fillings, use chair-side traps, vacuum pump filters and amalgam separators to retain amalgam, recycle their contents when possible and use line cleaners that minimise the dissolution of amalgam and avoid contamination of water.
At the national level, proper legislation and protocols are needed in order to phase out mercury. There is also need to revise the curriculum of dental teaching institutions and colleges to create awareness and follow the standard procedures for safe handling.
MARYAM SHABBIR ABBASI
Taxila
Phasing down use of mercury
Regarding the letter, “Mercury: Safe Dental Practice”, (Oct 20), in some of the dental teaching colleges and hospitals, due to lack of amalgam waste management at dental sites, the unregulated disposal of mercury in regular municipal and domestic waste and the extracted teeth that are incinerated, and heat sterilisation of amalgam filling dental instrument, have given birth to mercury pollution.
The common protocol of amalgam is the mechanised capsule system but still some dentists manually prepare amalgam by the mixing mercury and alloy in mortar and pestle.
The remaining mercury is either discarded into trash or sinks. The mercury or mercury amalgam waste is combined with other waste pointing no segregation; it is collected and disposed into either regular municipal waste or sewerage waste water.
The Sustainable Development Policy Institute’s study and review of curriculum of Pakistan Medical and Dental Council (PMDC), Higher Education Commission (HEC) and University of Health Sciences (UHS) followed in different dental teaching institutions of Pakistan indicated the absence of related topics concerning mercury exposure, oral injuries due to mercury poisoning, environmental degradation due to emission and release of mercury, safe environmental friendly management of mercury waste, preventive and protective measures in case of mercury spill.
It is an utmost need to teach and train dental professionals and students to utilise mercury-free alternatives enabling phasing out mercury from operative dentistry.
It is strongly suggested to PMDC, HEC and UHS to review and revise their curriculum in dental teaching institutions in the country by the inclusion of the above-mentioned topics and topics related to occupational health and safety, and to encourage the best waste management practice for amalgam waste.
SADAF NAWAZ
Islamabad