Biometals. 2009 Aug 21.
Assessment of chronic mercury exposure within the U.S. population, National Health and Nutrition Examination Survey, 1999-2006. Laks DR.
Abstract The purpose of this study was to assess chronic mercury exposure within the US population. Time trends were analyzed for blood inorganic mercury (I-Hg) levels in 6,174 women, ages 18-49, in the NHANES, 1999-2006 data sets. Multivariate logistic regression distinguished a significant, direct correlation within the US population between I-Hg detection and years since the start of the survey (OR = 1.49, P < 0.001). Within this population, I-Hg detection rose sharply from 2% in 1999-2000 to 30% in 2005-2006. In addition, the population averaged mean I-Hg concentration rose significantly over that same period from 0.33 to 0.39 mu/L (Anova, P < 0.001). In a separate analysis, multivariate logistic regression indicated that I-Hg detection was significantly associated with age (OR = 1.02, P < 0.001). Furthermore, multivariate logistic regression revealed significant associations of both I-Hg detection and mean concentration with biomarkers for the main targets of mercury deposition and effect: the liver, immune system, and pituitary. This study provides compelling evidence that I-Hg deposition within the human body is a cumulative process, increasing with age and in the population over time, since 1999, as a result of chronic mercury exposure. Furthermore, our results indicate that I-Hg deposition is associated with the significant biological markers for main targets of exposure, deposition, and effect. Accumulation of focal I-Hg deposits within the human body due to chronic mercury exposure provides a mechanism which suggests a time dependent rise in the population risks for associated disease.
This study is the first to report that there is a rise in the mean blood I-Hg detection and I-Hg concentration within the US population over time. The results of this study suggest that due to chronic mercury exposure, inorganic mercury deposits accumulate in organs of the human body, in a time dependent manner. Furthermore, this study indicates that I-Hg deposition within the human body is significantly associated with biomarkers for the main targets of chronic mercury exposure, deposition and effect: the
liver, immune system, and pituitary. These correlations between chronic mercury exposure, I-Hg deposition, and biochemical profile markers for the targets of I-Hg deposition confirm strong links between exposure and associated disease. The evidence presented in this study indicates that effects of chronic mercury exposure within the US population may result in a significant rise over time in the population risks of associated neuro-developmental and neurodegenerative diseases.
While we have a tremendous amount of respect for the work Dan Laks has done. We must take issue with his quoting Rodney Mackert's (ADA spokeman) findings of only 1.6 micrograms a day of mercury exposure from amalgam fillings.
In Mark Richardson's 2011 dental amalgam risk assessment, he compiled a chart (below) summarizing eighteen separate estimates of mercury exposure due to amalgam in adults. The range of the estimates intersects with limits recommended for non-occupational exposure by the US Environmental Protection Agency (EPA) and California's Environmental Protection Agency (CalEPA), as shown by the vertical blue and red lines.
Out of the eighteen studies that examined the amount of mercury exposure and absoption from mercury fillings, Rodney Mackert's findings are the lowest as detailed in the chart below.
Published Estimates of Hg Exposure in Adults With Dental Amalgam (Mercury Fillings)
Boyd Haley PhD
These measurements showed that mercury release from amalgams vastly exceed the ʻestimatedʼ release reported by ADA 'authority' Rodney Mackert, DDS, who claimed that 7 ﬁllings release only a single microgram of mercury per day - according to a Wall Street Journal article. It is important to note that Mackert, rather than directly measuring the actual quantity of mercury released by amalgams, instead "estimated" the amount of mercury released from amalgam ﬁllings by looking at the mercury level in the urine of several test subjects. Mackert has no training in toxicology as he is a practicing dental materials expert.
It is well established that less than 10% of mercury leaves the body by the kidney/urinary route (the vast majority leaving by the bilary transport/fecal route). As a result of this ﬂawed methodology the ADA estimated level of mercury release by amalgam grossly understates the amount of the mercury released.