Regulating Mercury Amalgam Use at Private Dental Clinics in Pakista (PB - 45)

Regulating Mercury Amalgam Use at Private Dental Clinics in Pakista (PB - 45)

Publication details

  • Friday | 06 Nov, 2015
  • Mahmood A. Khwaja, S. Waqar Ali
  • Policy Briefs/Papers
  • 29
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Mahmood A. Khwaja and S.Waqar Ali 


Mercury, one of the most hazardous chemicals, has become a growing issue of global concern because of its adverse environmental and health impacts (ATSDR 2011). Despite its toxic properties, mercury is widely used in dental amalgams for filling cavities caused by caries (SOU 2003). Dental amalgam is typically composed of approximately 50% mercury, 34.5% silver, 9% tin, 6% copper, and 0.5% zinc by weight (Alt Inc. 2005). The dentist’s occupational exposure to mercury vaporus occurs to a large extent during direct clinical work with preparation of dental amalgam restorative material, as well as during cutting, filling and polishing operations (Morton et al. 2004; Ely, 1997). It is estimated that in human, 60 per cent of Mercury exposure results from dental amalgam in the oral cavity via inhalation of mercury vapours and 40 per cent of mercury exposure is via ingestion (Spencer 2000). A person having dental mercury amalgam filling on the average absorbs about 3-17micrograms of mercury (Weinberg 2010). Mercury poisoning may damage the nervous system, lungs, and kidneys. Exposure to mercury of vulnerable population (dental professionals, healthcare workers, children, pregnant women, and elderly) is of particular concern. The nervous system is most sensitive to mercury exposure (OPH 2008). Children are more at risk from mercury poisoning, which affects their neurological development and brain. According to the World Health Organization, dentists are among the health professionals with higher occupational exposure to mercury vapours (World Health Organization 1991; Morton et al. 2004).

Very few investigations on mercury amalgam use in the dentistry sector have been carried out in South Asia (including Pakistan) and there is little data reported on mercury contamination of indoor/outdoor air at dental healthcare sites, dental teaching institutions, hospitals & private dental clinics. In Pakistan, mercury emission and transfer are mainly from extraction and use of fuels, intentional use of mercury in industrial processes, and in others, such as dental mercury-amalgam fillings, medical equipment’s, waste deposition/land fillings and waste water-treatment (MoE 2000). Studies on dental amalgam use and mercury contaminated waste disposal practices by dental professionals in Pakistan have been reported by Rubina et al.  (2010) and Iqbal et al. (2011). SDPI studies indicated alarmingly high mercury levels in the air (indoor as well as outdoor) at 11 of the 34 visited dental sites (17 dental teaching institutions, 7 general hospitals & 10 dental clinics) in five main cities of Pakistan (Khwaja & Maryum 2014; Khwaja et al.  2014). Responses from dental professionals at 38 dental institutions in Pakistan showed general unawareness among dental professionals regarding mercury containing wastes and lack of awareness about health hazards of mercury exposure to human health (Khwaja & Sadaf 2014). A recent study carried out by Gul (2015) at Peshawar University, Pakistan  on appropriate handling of mercury/mercury amalgam, environmentally unsound management of biological samples (RBCs, plasma, urine, hair & nails) of individuals with mercury dental amalgam (n=30) and controlled samples (n=30)) have shown mercury concentration 6 – 8 times higher than the controlled samples (individuals without dental mercury amalgam). 

In view of the earlier SDPI studies mentioned above, indicating high indoor air mercury levels within private dental clinics and lack of awareness among dental professionals regarding mercury related occupational health and safety issues, the present study was conducted to assess the status of mercury amalgam use in private dental clinics. In the light of the findings described and discussed in the following pages to safeguard public health and for the protection of environment, it is strongly recommended that since mercury amalgam use cannot be banned immediately in the country, its use may be regularized and allowed subject to use of “Amalgam Separators,” “Capsulated Mercury” and “Mechanized Mixing ban on use of mercury amalgam for children (below 12 years age) and pregnant women.  A review/revision of the curriculum currently being taught at medical and dental colleges in the country should be conducted to ensure adequate training towards minimizing mercury exposure,  and mercury amalgam use in dentistry.