Environmental Toxins and Autism
By Marcia Zimmerman, C.N.
“Recent studies suggest a substantial increase in autism prevalence . . . only partially explicable by data artifacts – underscore(es) the possibility of environmental contributors.” Martha Herbert, M.D.,Ph.D. Pediatric Neurologist, Massachusetts General Hospital, Charleston, Massachusetts
Environmental contributors in autism spectrum disorders (ASD) are being increasingly investigated with the recognition that children with ASD are exceptionally vulnerable to the effects of toxic exposure. Environmental triggers for ASD may actually begin in utero as the embryonic brain, nervous system, and other body systems are developing.(1) Mercury is the target of particular focus. Let’s begin with vaccines.
Parents have long suspected that mercury containing vaccines were responsible for the development of autism in their child.(2) The measles, mumps, and rubella (MMR) vaccine has been under the radar but also other routine childhood vaccines that contain thimerosal, a mercuric preservative.(3),(4) Yet recent research has not found any evidence that MMR vaccination, using either multiple dose vaccines that contain thimerosal or single-dose vaccine without it, is by itself a likely cause.(5) So does this leave mercury as a causative factor out of the picture? Not at all! Mercury is a known neurotoxin and has drawn increased scientific scrutiny in the fight to find causes for the burgeoning number of children diagnosed with an autism spectrum disorder.(6)
Mercury: Primary Environmental Threat
Mercury is a heavy metal found naturally in trace amounts in the earth’s atmosphere in different forms – as elemental vapor, reactive gaseous compounds, or particulate matter. Studies have shown that levels of environmental mercury have steadily increased since the pre-industrial era. (7) The primary source of contamination comes from coal-fired utility plants (33%), municipal/medical waste incinerators (29%), and commercial/industrial boilers (18%).6 The U.S. Environmental Protection Agency (EPA) has estimated that 158 tons of environmental mercury is released each year. (8)
Other sources of contamination include dental amalgams, personal care products (nasal sprays, contact lens solution), hazardous waste sites (medical, industrial), cement factories, household items (thermometers, lamps, batteries), and chlorine production plants. Fourteen percent of plants producing chorine products do so by the mercury cell chlor-alkali process.(9) This industry has been the largest discharger of mercury into water and is gradually being replaced in the U.S. with membrane grade technology.(10)
Impact of Mercury Contamination on Children
Mercury ranks third among the most frequently found toxic metals; behind arsenic and lead. Cadmium, another toxic metal with substantial health risks, ranks seventh.(11) Among these, mercury has the greatest impact on the unborn and young children who are most susceptible to its effects. They lack the ability to clear mercury, both organic and inorganic, from their bodies. (6), (12), (13)
Infants may be further exposed to toxic levels of mercury through lactation, if their mother is toxic. Mother’s fish consumption and number of dental amalgams contribute to her toxicity and risk to her child.(14) Fish are a potential source of methylmercury – a particularly toxic form – and the reason EPA and FDA have set limits on fish consumption among young children, pregnant and lactating women.(15)
Breast milk has long been accepted as the ideal food for newborns. A new Dutch study of 4,164 infants suggests feeding infants solely on mother’s milk for at least four and preferably six months, reduces the incidence of infectious disease.(16) Clearly this gives babies a jump start and it emphasizes the need for efforts to decrease mercury burden in women who are pregnant, planning to get pregnant, or are lactating.
We will continue our discussion of autism spectrum disorders by exploring, testing, detoxification, and nutrition solutions in upcoming Z-Files. My upcoming monthly webinars will cover autism spectrum disorders in more detail. Register today for the free presentation on July 19th. https://www.now-university.com/Webinars/ For more on other environmental contaminants go to my article on Endocrine Disruptors – Hidden Dangers, February 2008. You can also read my Z-File article (April 2009) on mercury in high fructose corn syrup; High Fructose Corn Syrup – More Than You Bargained For?. http://www.naturalhealthresearch.org/nhri/?page_id=320www
References:
1) Herbert M.R.; “Contributions of the Environment and Environmentally Vulnerable Physiology to Autism Spectrum Disorders” Curr Opin Neurol 2010;23:000-000. DOI:10.1097/WCO.ob013e32833a01f.
2) Bardenheier, B.; et al.; “Are Parental Vaccine Safety Concerns Associated With Receipt of Measles-Mumps_Rubella, Diptheria and Tetanus Toxoids with Acellular Pertussis, or Hepatitis B Vaccines by Children?” Arch Pediatr Adolesc Med 2004;158:569-575
3) Miller, L.; Reynolds, J.; “Autism and Vaccination – The Current Evidence” JSPN 2009;14:166-172.
4) Bakes, JP.; “Mercury, Vaccines, and autism” Am J Pub Health 2008;98:244-253.
5) Mrozek-Budzyn, D.; et al.; “Lack of Association Between Measles-Mumps-Rubella Vaccination and Autism in Children” Pediatr Infect Dis J 2010;29:397-400
6) Daniel, KT.; Knight, GD.; “Mad as a Hatter: How to Avoid Toxic Metals and Clear Them from the Body” Wise Traditions, summer 2008:33-45.
7) Irwin, RJ.; et al.; “Environmental Contaminants Encyclopedia Mercury Entry” 1997; National Park Service http://www.nature.nps.gov/hazardssafety/toxic/mercury.pdf
8) Palmer, RF; “Proximity to Point Sources of Environmental Mercury Release as a Predictor of Autism Prevalence” 2009; Health & Place 15:18-24.
9) “Industrial Sources of Mercury and Applicable Mercury-Specific Regulations;” Mercury Sources and Regulations Appendix B: Virtual Elimination Pilot Project, Ross & Associates Environmental Consulting, Ltd.
10) “Mercury” Pollution Prevention and Abatement Handbook World Bank Group 1998 pp. 219-222.
11) “2007 CERCLA Substance List “; Agency for Toxic Substances & Disease Registry, Department of Health and Human Services. www.atsdr.edc.gov/cercla/07list.html.
12) James, S.J.; et al.; “Cellular and Mitochondrial Glutathione Redox Imbalance in Lymphoblastoid Cells Derived From Children With Autism” FASEB J 2009;23:2374-2383.
13) Herbert, MR. Op. Cit.
14) Oskarsson A.; et al.; “Total and Inorganic Mercury in Breast Milk and Blood in Relation to Fish Consumption and Amalgam Fillings in Lactating Women” Arch Environ Health 1996;51:234-241
15) “Information About Mercury Exposure and Effects” Environmental Protection Agency; www.epa.gov/mercury.
16) Duijts, L.; et al.; “Prolonged and Exclusive Breastfeeding Reduces the Risk of Infectious Diseases in Infancy” Pediatrics June 21, 2010:DOI:10.1542/peds.2008-3256.