Navigation Links
Mercury Levels Not Abnormal in Autistic Children
Date:10/19/2009

Study finds no differences when compared to kids without disorder

MONDAY, Oct. 19 (HealthDay News) -- A new study finds no differences in blood mercury levels between children who are developing normally and those diagnosed with autism or autism spectrum disorders.

The findings, appearing online Oct. 19 in the journal Environmental Health Perspectives, may quell some of the debate surrounding mercury and autism.

The researchers did not, for instance, look at whether mercury might play a causal role in this group of developmental disorders.

"This is an excellent study that has addressed a very important question for many families about the role of mercury [in autism]," said Dr. Patricia Manning-Courtney, medical director of The Kelly O'Leary Center for Autism Spectrum Disorders at Cincinnati Children's Hospital Medical Center. "It's a very clear study [in] that no differences in mercury were seen. Is it going to put the questions to rest? I think no. It's another important contribution to the large body of knowledge on this topic, but I think it will still be an area of great controversy."

Previous studies have shown higher blood mercury levels in people with autism, but the results, along with the quality of the studies, have been inconsistent.

One of the biggest controversies claims that vaccines containing the preservative thimerosal, which contains mercury, might cause autism.

But thimerosal is no longer used routinely in children's vaccines and, earlier this year, a U.S. court ruled that there is no scientific evidence that childhood vaccines such as the measles-mumps-rubella vaccine caused autism in children of parents seeking compensation from a federal fund.

The authors of this study wanted to fill one gap in the research: a lack of good evidence comparing mercury levels in children with autism and children without autism.

The authors looked at 452 children aged 2 to 5, who either had autism/autism spectrum disorder, developmental delays other than autism (such as Down syndrome), or who were developing normally.

Blood samples were taken from the children while mothers answered questions about different possible exposures to mercury, such as diet, dental amalgams, thimerosal-containing vaccines and even personal-care products such as earwax removal systems and nasal sprays.

First results showed that children with autism actually had much lower levels of mercury in their blood, but this was explained by the fact that these children ate less fish.

When the results were adjusted for this and other variables, mercury levels came out about the same between the autism group and the control group.

"Not only do we not see differences, but the values are pretty close to national averages," said study author Irva Hertz-Picciotto, chief of environmental and occupational health and a faculty member at the MIND Institute at the University of California, Davis.

Overall, children with developmental delays other than autism had lower blood mercury concentrations.

Children who had mercury-based dental fillings who ground their teeth or chewed gum had blood concentrations of the metal. And those few children who had had a mercury-containing vaccine did not show elevations in their blood levels.

"The relationship between [mercury] intake to blood levels seems to follow the pattern that we expect and it's well known that most of the mercury in the body does come from fish consumption," Hertz-Picciotto said. "There really were very few children who had vaccines that would have or could have contained thimerosal."

Most of the children in the study had received vaccines after thimerosal was removed from vaccines, she said.

Mercury only has a half-life in the circulating blood of a few months, Hertz-Picciotto said, so "clearly this does not tell us anything causal because all of the mercury represents exposure that had happened post-diagnosis."

Sallie Bernard, executive director of SafeMinds (Sensible Action for Ending Mercury-Induced Neurological Disorders), expressed concern about confusing the findings with the interpretation of the findings.

"An interpretation says the study shows no link between mercury and autism, but that's not what the paper is saying," Bernard said. "It says they looked to see if [there] was higher exposure in kids with autism after they got their diagnosis. These are current exposures, not what might have happened at an earlier time point in pregnancy or in the first year of life, so you don't know what affect that might have had."

The study also does not go into whether certain children may be more susceptible to mercury's effects, she said.

More information

Learn more about autism spectrum disorders at the U.S. Centers for Disease Control and Prevention.



SOURCES: Irva Hertz-Picciotto, Ph.D., chief, environmental and occupational health, and faculty member, MIND Institute, University of California, Davis; Patricia Manning-Courtney, M.D., associate professor, clinical pediatrics, and medical director, The Kelly O'Leary Center for Autism Spectrum Disorders, Cincinnati Children's Hospital Medical Center; Sallie Bernard, executive director, SafeMinds (Sensible Action for Ending Mercury-Induced Neurological Disorders); Oct. 19, 2009, Environmental Health Perspectives, online


'/>"/>
Copyright©2009 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Most comprehensive study of mercury in dental fillings begins
2. New Fish Advice Throws Baby Out With the Bath Water, Says Mercury Watchdog Group
3. A Patients Right to Know: Silver Fillings are 50% Mercury
4. Store-bought freshwater fish contain elevated levels of mercury, arsenic and selenium
5. Environmental Impacts of Dental Mercury Focus of U.S. House Oversight Hearing Wednesday
6. EPA Plan to Evade Required Cuts in Mercury Pollution Challenged in Court by States, Tribes, Health and Environmental Groups
7. ABC Drama, Eli Stone, Tackles Autism-Mercury Controversy
8. Mercury in Childhood Vaccines Excreted Quickly
9. Global Consensus on Mercury: Scientists Defend Science Journalists
10. Ongoing Tests Show Kona Kampachi(R) is Rich in Omega-3s With No Detectable Mercury
11. Scientists find mercury threatens next generation of loons
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... June 25, 2016 , ... Austin residents seeking Mohs surgery services, can now ... and to Dr. Russell Peckham for medical and surgical dermatology. , Dr. Dorsey brings ... The selective fellowship in Mohs Micrographic Surgery completed by Dr. Dorsey was under the ...
(Date:6/25/2016)... ... June 25, 2016 , ... Dr. Calvin Johnson has dedicated ... has implemented orthobiologic procedures as a method for treating his patients. The procedure ... doctors to perform the treatment. Orthobiologics are substances that orthopaedic surgeons use to ...
(Date:6/24/2016)... ... ... June 19, 2016 is World Sickle Cell Observance Day. In an effort to ... treatments, Serenity Recovery Center of Marne, Michigan, has issued a pain management ... (SCD) is a disorder of the red blood cells, which can cause episodes of ...
(Date:6/24/2016)... ... June 24, 2016 , ... Comfort Keepers® of San Diego, CA is excited ... To Recovery® program to drive cancer patients to and from their cancer treatments. ... highest quality of life and ongoing independence. Getting to and from medical treatments ...
(Date:6/24/2016)... ... 24, 2016 , ... Puradigm® & Innovative Solutions today announced ... and processing operations at its production facility, and opened its first two dispensaries ... manufacturer of a complete system of proactive air and surface purification solutions for ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... -- The Academy of Managed Care Pharmacy (AMCP) today ... allow biopharmaceutical companies to more easily share health care ... coverage decisions, a move that addresses the growing need ... The recommendations address restrictions in the sharing of product ... a prohibition that hinders decision makers from accessing HCEI ...
(Date:6/24/2016)... , June 24, 2016 Research ... World Market for Companion Diagnostic Tests" report to their ... Market for Companion Diagnostics The World Market ... and personalized medicine diagnostics. Market analysis in the report includes ... Test Market (In Vitro Diagnostic Kits) by Region (N. America, ...
(Date:6/24/2016)... Belgium , June 24, 2016 ... today announced the appointment of Dr. Edward ... as a Non-Executive Director, effective June 23, 2016.Dr. ... Compensation and Nominations and Governance Committees.  As a ... will provide independent expertise and strategic counsel to ...
Breaking Medicine Technology: