David Kirby is touring Canada to promote his book, Evidence of Harm, that argues for a connection between the mercury based preservative thimerosal (until recently this was used in the manufacture of many early childhood vaccines) and an apparent increase in autism prevalence.
Canada, too has experienced an apparent increase as well. According to the Autism Society of Canada:
Epidemiological studies are still in the early stages in Canada and more surveillance and research are needed to develop accurate data on the prevalence of ASDs. The current prevalence of ASDs nationwide is estimated to be more than 1 in 200. (Fombonne, E., 2003: Modern Views of Autism, Can. J. Psychiatry, 48:503-505. Fombonne, E., 2003: Epidemiology of autism and other pervasive developmental disorders: an update. J. Autism. Dev. Disord. 33:365-381).
The ad for Kirby’s tour makes a number of claims.
“In some parts of Canada, children received mercury in their vaccines until at least 2002, and perhaps beyond; the residual effects of which we are seeing in the number of rising and confirmed cases of autism.”
If you look at the population map below the dark colours show where most Canadians live. Kirby’s tour takes him to some of the most heavily populated provinces: Ontario, Quebec and Manitoba with lots of autistic children. The only problem is that very few parts of Canada ever used thimerosal containing vaccines and then only in the Hep B vaccine.
New Brunswick, Prince Edward Island, Yukon and Northwest Territories were the only jurisdictions in Canada with a universal infant hepatitis B immunization program in 1999. The total population of these areas is less than 1 million compared with a total population of over 30 million for Canada as a whole. Since 2002 they have been joined by Britiash Columbia (pop 4,154,053) and Nunavut (pop 30,776) All population figures are taken from here.
Exposure to thimerosal is still very small. The Public Health Agency of Canada states that Canadian infants from the above six Canadian jurisdictions could have been exposed to between 12.5 µg and 37.5 µg of ethylmercury in the first 6 months of life (or an average of 0.069 µg/day to 0.206 µg/day), from thimerosal-containing hepatitis B vaccine. And for 75% of Canada’s children there is no exposure at all. Yet there are still autism societies up and running covering nearly the whole of Canada.
I hope the people who attend Kirby’s seminars ask him to explain why they have comparable levels of autism with the USA and NO HISTORY OF MERCURY IN THEIR VACCINES
Kirby’s second claim is that
“A recent university study showed that children exposed to high levels of environmental mercury were at increased risk of developing autism”
I guess that some of the highest exposures to mercury come from eating fish. And the Inuit who make up the majority of the population in Nunavut have historically consumed more fish than anyone else in Canada. Their cumulative burden of environmental mercury ought to be similarly higher. Yet Nunavut is the one part of Canada that does not have an autism society.
That is because THERE ARE NO AUTISTIC INUIT. Eric Fombonne is a world renowned authority on autism and, from his base in Montreal he has had a lot to do with the Inuit. For 15 years he and his team have been providing healthcare to 11000 Inuit and have found no cases of autism at all. Please go to Kev’s blog and read their abstract along with others finding no difference between mercury levels in the hair and the blood of autistic and non-autistic children.
That ought to be the end of the thimerosal/autism charade. But somehow I doubt it.