Mercury in saliva and the risk of exceeding limits for sewage in relation to exposure to amalgam fillings

Arch Environ Health. 2002 Jul-Aug;57(4):366-70. doi: 10.1080/00039890209601423.


The concentration of total mercury in stimulated saliva was studied in humans with dental amalgam fillings and in 2 nonamalgam groups. The probability of exceeding the limits of mercury permitted in wastewater increased proportionally as the number of amalgam-filled surfaces increased. The mercury limit for sewage is 0.05 mg/l (= 250 nmol/l) effluent, according to the Council of European Communities directive 84/156/EEC. In neither of the nonamalgam groups was this limit exceeded, but 20.5% in the amalgam group exceeded the limit (p < .001). The risk of exceeding the limit increased 2-fold for every 10 additional amalgam-filled surfaces (odds ratio = 2.0; 95% confidence interval = 1.3, 3.3). 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Dental Amalgam / chemistry*
  • Drug Resistance, Microbial
  • Environmental Exposure*
  • Environmental Pollutants
  • Female
  • Humans
  • Male
  • Mercury / adverse effects
  • Mercury / analysis*
  • Middle Aged
  • Risk Assessment
  • Saliva / chemistry
  • Sewage / chemistry*
  • Waste Disposal, Fluid


  • Environmental Pollutants
  • Sewage
  • Dental Amalgam
  • Mercury