Are Neuropathological Conditions Relevant to Ethylmercury Exposure?

Abstract

Mercury and mercurial compounds are among the environmentally ubiquitous substances most toxic to both wildlife and humans. Once released into the environment from both natural and anthropogenic sources, mercury exists mainly as three different molecular species: elemental, inorganic, and organic. Potential health risks have been reported from exposure to all forms; however, of particular concern for human exposure relate to the potent neurotoxic effects of methylmercury (MeHg), especially for the developing nervous system. The general population is primarily exposed to MeHg by seafood consumption. In addition, some pharmaceuticals, including vaccines, have been, and some continue to be, a ubiquitous source of exposure to mercurials. A significant controversy has been whether the vaccine preservative ethylmercury thiosalicylate, commonly known as thimerosal, could cause the development of autism. In this review, we have discussed the hypothesis that exposure to thimerosal during childhood may be a primary cause of autism. The conclusion is that there are no reliable data indicating that administration of vaccines containing thimerosal is a primary cause of autism. However, one cannot rule out the possibility that the individual gene profile and/or gene-environment interactions may play a role in modulating the response to acquired risk by modifying the individual susceptibility.

Seven-Year Neurodevelopmental Scores and Prenatal Exposure to Chlorpyrifos, a Common Agricultural Pesticide

“…This observation may indicate an impaired detoxification mechanism as a risk factor that significantly contributes to the etiology of autism. The exposure of patients with ASD in early childhood to mercury vapor, methylmercury and ethylmercury may occur through dental amalgams, fish intake and vaccinations [30][31][32]. Furthermore, in this study, remarkably higher levels of Hg and Pb were recorded in patients with severe social and cognition impairment (SRS & CARS) compared with those with mild-moderate abnormalities.…”

The Role of Heavy Metal Pollution in Neurobehavioral Disorders: a Focus on Autism

“…In contrast, other reports did not find any association between thimerosal-containing vaccines and ASD (Croen et al 2008 Price et al 2010;Schultz 2010) or neuropsychological impairments (Parker et al 2004;Marques et al 2010;Chen et al 2013). To date, there are no reliable data confirming thimerosal as an etiological agent in autism development; however, it cannot be excluded that individual gene profile and gene-environment interaction may play a dramatic role in modulating the individual response to TM risk exposure (Aschner and Ceccatelli 2010).…”

Global Justice and the Proposed Ban on Thimerosal-Containing Vaccines

“…Extensive pharmacologic and epidemiological research has shown early, theoretical concerns about links to autism or other neurodevelopmental disorders to be false. [10][11][12][13][14][15] Indeed, the exculpatory strength of the data now available on thimerosal is well evidenced by recent statements from the Global Advisory Committee on Vaccine Safety, 16 US Institute of Medicine, 17 and American Academy of Pediatrics, 18 all of which have concluded that thimerosal exposure through vaccination is not harmful to human health.…”