Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 23 (6), 1691-1718

Systematic Assessment of Research on Autism Spectrum Disorder (ASD) and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research


Systematic Assessment of Research on Autism Spectrum Disorder (ASD) and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research

Janet K Kern et al. Sci Eng Ethics.

Retraction in


Historically, entities with a vested interest in a product that critics have suggested is harmful have consistently used research to back their claims that the product is safe. Prominent examples are: tobacco, lead, bisphenol A, and atrazine. Research literature indicates that about 80-90% of studies with industry affiliation found no harm from the product, while only about 10-20% of studies without industry affiliation found no harm. In parallel to other historical debates, recent studies examining a possible relationship between mercury (Hg) exposure and autism spectrum disorder (ASD) show a similar dichotomy. Studies sponsored and supported by industry or entities with an apparent conflict of interest have most often shown no evidence of harm or no "consistent" evidence of harm, while studies without such affiliations report positive evidence of a Hg/autism association. The potentially causal relationship between Hg exposure and ASD differs from other toxic products since there is a broad coalition of entities for whom a conflict of interest arises. These include influential governmental public health entities, the pharmaceutical industry, and even the coal burning industry. This review includes a systematic literature search of original studies on the potential relationship between Hg and ASD from 1999 to August 2015, finding that of the studies with public health and/or industry affiliation, 86% reported no relationship between Hg and ASD. However, among studies without public health and/or industry affiliation, only 21% find no relationship between Hg and ASD. The discrepancy in these results suggests a bias indicative of a conflict of interest.

Keywords: ASD; Autism; Conflict of interest; Mercury; Toxins; Transparency.

Conflict of interest statement

Janet Kern is a board member of the Council for Nutritional and Environmental Medicine (CONEM) and Geir Bjørklund is that organization’s founder and president. Mark Geier and David Geier do work under the auspices of the non-profit Institute for Chronic Illnesses, Inc. Lisa Sykes, Mark Geier and David Geier are officers of the Coalition for Mercury-free Drugs (CoMeD, Inc). Richard Deth is on the scientific advisory board of the National Autism Association. Brian Hooker is on the board of Focus for Health. James Love has been involved in amalgam litigation. Boyd Haley is involved in the development of a mercury-chelating agent. Some of the authors have a personal as well as a professional interest in autism. In addition, some authors have been involved in litigation related to vaccines and autism.

Similar articles

See all similar articles

Cited by 2 articles


    1. Abdullah MM, Ly AR, Goldberg WA, Clarke-Stewart KA, Dudgeon JV, Mull CG, Chan TJ, Kent EE, Mason AZ, Ericson JE. Heavy metal in children’s tooth enamel: Related to autism and disruptive behaviors? Journal of Autism and Developmental Disorders. 2012;42(6):929–936. doi: 10.1007/s10803-011-1318-6. - DOI - PubMed
    1. Adams JB, Audhya T, McDonough-Means S, Rubin RA, Quig D, Geis E, Gehn E, Loresto M, Mitchell J, Atwood S, Barnhouse S, Lee W. Toxicological status of children with autism vs. neurotypical children and the association with autism severity. Biological Trace Element Research. 2013;151(2):171–180. doi: 10.1007/s12011-012-9551-1. - DOI - PubMed
    1. Adams JB, Romdalvik J, Ramanujam VM, Legator MS. Mercury, lead, and zinc in baby teeth of children with autism versus controls. Journal of Toxicology and Environmental Health, Part A. 2007;70(12):1046–1051. doi: 10.1080/15287390601172080. - DOI - PubMed
    1. Alabdali A, Al-Ayadhi L, El-Ansary A. A key role for an impaired detoxification mechanism in the etiology and severity of autism spectrum disorders. Behavioral and Brain Functions. 2014;10:14. doi: 10.1186/1744-9081-10-14. - DOI - PMC - PubMed
    1. Al-Ayadhi LY. Heavy metals and trace elements in hair samples of autistic children in central Saudi Arabia. Neurosciences (Riyadh) 2005;10(3):213–218. - PubMed