One of the arguments for the mercury-causes-autism hypothesis is that there are subgroups more susceptible to harm from mercury exposures. It is argued that pink disease gives an example for such a susceptibility group.
Pink disease was a reaction to a teething powder which contained mercury. About 1 in 500 children exposed to the powder reacted with pink disease. Two points are important to keep in mind. First, the levels of mercury exposure from the powder were far greater than from vaccines. Second, the exposures were not the same for all children. Some parents would use more teething powder at a time. Some might use it for longer times. This makes it impossible to claim a susceptibility group as the children who showed signs of pink disease could very likely be the ones who had higher levels of mercury exposure.
In a paper just released, a team of researchers interviewed people who had a history of pink disease. Since that teething powder has been gone for decades, these individuals are now old enough to be grandparents.
This is, at best, a very strange paper. Consider these questions:
1) why aren’t they reporting a high autism prevalence in the people who had very high mercury exposures and who showed signs of pink disease? If there is a genetic susceptibility, why isn’t it seen in those with the greatest exposures?
2) why isn’t there a report of high autism prevalence in the children, just the grandchildren? My guess is that the response from some will be that the grandchildren received higher doses of mercury in vaccines than did their parents. Which again would beg the question of where is the high rate of autism in those exposed to the teething powders, especially those who developed pink disease.
The conclusions of this paper have some major logical hurdles to overcome, to say the least. And this is even before the methods are addressed. For example, this all hinges on reports by the grandparents. Not on an actual prevalence measure of the decendents.
If is already well established that the rise in mercury exposures from childhood vaccines was not the cause of the rise in autism prevalence estimates. It has always been clear that autism is not similar to mercury poisoning symptoms. The mercury hypothesis has been harmful, both to public health and the autism communities The time for papers which pose intriguing questions on this subject has past. Studies with weak methods and poor logic are irresponsible in today’s world.
Here is the abstract:
Pink disease (infantile acrodynia) was especially prevalent in the first half of the 20th century. Primarily attributed to exposure to mercury (Hg) commonly found in teething powders, the condition was developed by approximately 1 in 500 exposed children. The differential risk factor was identified as an idiosyncratic sensitivity to Hg. Autism spectrum disorders (ASD) have also been postulated to be produced by Hg. Analogous to the pink disease experience, Hg exposure is widespread yet only a fraction of exposed children develop an ASD, suggesting sensitivity to Hg may also be present in children with an ASD. The objective of this study was to test the hypothesis that individuals with a known hypersensitivity to Hg (pink disease survivors) may be more likely to have descendants with an ASD. Five hundred and twenty-two participants who had previously been diagnosed with pink disease completed a survey on the health outcomes of their descendants. The prevalence rates of ASD and a variety of other clinical conditions diagnosed in childhood (attention deficit hyperactivity disorder, epilepsy, Fragile X syndrome, and Down syndrome) were compared to well-established general population prevalence rates. The results showed the prevalence rate of ASD among the grandchildren of pink disease survivors (1 in 22) to be significantly higher than the comparable general population prevalence rate (1 in 160). The results support the hypothesis that Hg sensitivity may be a heritable/genetic risk factor for ASD.