Author: Richardson GM
Source: Human and Ecological Risk Assessment
Year: 1996
Comment:
Abstract / Excerpt:
“Dental amalgam is approximately 50% mercury (Hg) by weight, and persons bearing amalgam fillings are exposed to this element, primarily as Hg vapor. For Canadians with amalgam-filled teeth, it was estimated, based on two independent models, that Hg exposure from amalgam averaged: 0.045 to 0.082 Jlglkg bw/day in toddlers (aged 3 to 4 years); 0.044 to 0.069 flg/kg bw/day in children (aged 5 to 11 years); 0.034 to 0.044 flg/kg bw/day in teens (aged 12 to 19 years); 0.050 to 0.055 flg/kg bw/day in adults (aged 20 to 59 years); and 0.031 to 0.041 flg/kg bw/day in seniors (aged 60+ years). Amalgam was estimated to contribute, on average, 50% of total Hg exposure from all sources (amalgam, air, water, food, soil) in adults, and 32 to 42% for other age groups. Numerous studies have consistently reported effects on the central nervous system (CNS) in persons occupationally exposed to Hg vapor. Most such studies have failed to detect a threshold for the CNS effects measured. A tolerable daily intake (TDI) of 0.014 flg Hg/kg body weight/day (as an absorbed dose) was proposed for inhalation of mercury vapor, the principal form ofHg to which bearers of amalgam fillings are exposed. This TDI was based on a published account of subclinical (i.e., not resulting in overt symptoms or medical care) CNS effects in occupationally-exposed men, expressed as slight tremor of the forearm, and should also protect against cognitive function impairment. Based on the least conservative exposure model of the two independent models developed, the average numbers of amalgam-filled teeth estimated nor to compromise the TDI were: 1 filling in toddlers; 1 filling in children; 3 fillings in teens; and 4 fillings in adults and seniors.”
Citation:
Richardson GM. A Monte Carlo assessment of mercury exposure and risks from dental amalgam. Human and Ecological Risk Assessment. 1996; 2(4): 709-761.