Where are all the autistic children of dentists?

photo credit-Conor Lawless
Creative Commons license

Once again, the purported link between mercury/thimerosal and autism is in the news. This months "Archives in General Psychiatry" contains an article which looks at the continuing increase in the reported prevalence of autism in California while the amount of mercury is declining, and there is also an accompanying commentary in the same issue.

This article and commentary were discussed by Kristina Chew. Mark Blaxill, a leading proponent of the "autism=mercury poisoning" line of thought, backpeddles somewhat without totally conceding that the theory is dead. Brett of 29 Marbles asks what it would take for either side to change their mind.

Although I ultimately look to science to inform my opinions on things such as causality, I am not above referring to common sense, which is not a bad place to start when considering what kind of studies should be done.

One of the things that has made me doubt the whole autism=mercury poisoning thing from the start are dentists, and the amalgams they place. Specifically, where are all the autistic kids who had dentists and dental assistants as parents? More specifically, where is the large group of autistics that are 35-55 years old that had dentists or dental assistants as parents?

Why do I choose that age range? For a couple of reasons. Since autism wasn't described until the 1940's or so, I wouldn't expect older autistics. Also, this period would correspond to a time when dental caries were rampant (pre-fluoridation of water), as well as a time when handling of mercury and amalgam in dental offices was very casual. Mercury and metal filings (silver and zinc) used to be hand measured into a device, which then shook them together (right at the chairside) until they became a soft "amalgam" which was then packed into the cavity in the tooth. The dentist is typically "right in your face" as (s)he packs the amalgam into the tooth.

While some people today still blame mercury fillings for the exceedingly small amount of mercury vapor that is released by chewing on amalgam fillings, no one disputes that the greatest period of exposure to mercury is when the amalgam is first being mixed together. Since the 1970's or so, dental amalgams have come in a pre-proportioned sealed container, which minimizes the amount of mercury in the air in a dental office. Also, the number of amalgams that are placed today, while still large, pales compared to the past. Fluoridation started in the U.S. in 1955, and by the 1960's started to catch on. This resulted in a lot less exposure to mercury per child.

But between the time that autism was first described and the decline in amalgam fillings being placed in children there should have been an epidemic of children identified with autism, which declined as fillings per child dropped off. There should have been an even bigger incidence in the children of dental workers (dentists and dental assistants) who were occupationally exposed on a large scale to mercury vapor.

Where are they?

There are no studies that have shown this, and I am not even aware of any anecdotes of this phenomenon happening.

Definitely Strange

One of the blogs that I like to visit periodically is by a pediatrician, who goes by the name of "Dr. Flea". Flea covers a lot of territory with his posts, and has had multiple posts that are supportive of the autism community and dismissive of the anti-vaccine crowd.

In perusing his blog recently, I noted a most unusual post. If ever one doubted that there are some serious nutjobs out there promoting the whole "mercury causes autism" thing, Dr. Rebecca Carley is proof of how "out there" some of these people can be. The photo above is from her web site.

Looking at her rambling, single spaced website, Carley goes on about how vaccines cause autism, cancer, autoimmune diseases, and shaken baby syndrome. She lists a phone number that you can call to get advice on how to reverse your disease with natural remedies. As she states:

...DR CARLEY HAS CLIENTS (BOTH PEOPLE AND PETS) ALL OVER THE WORLD, AND DOES NOT NEED TO SEE YOU IN PERSON! YOUR PROTOCOL TEACHING YOU HOW TO REVERSE YOUR AUTOIMMUNE DISEASE OR CANCER IS CREATED BASED ON YOUR INDIVIDUAL HISTORY. ...

It's great that you don't even have to have an office visit to get diagnosed and treated by this quack.

Fortunately for society, and as Flea notes, her license to practice medicine was revoked in 2004. A review of her website and hearing proceedings of the medical board reveal that she has had serious problems for years.

Looking at her CV, she completed 4 years (out of a usual 5) of a general surgery residency. This is usually a red flag that something was noticed to be wrong by her program. She was accepted into a Physical Medicine and Rehabilitation residency program, but washed out of that in two months. She subsequently practiced as an emergency room physician for a few years, and one year as a surgical house officer. The CV notes nothing for several years, then notes that she took multiple "Alternative Medicine" courses and seminars over 2 years. She subsequently claims to have started a new medical specialty,

VIDS (Vaccine Induced Diseas Syndromes, which includes all autoimmune diseases and cancers).

There was a psychiatric evaluation done as part of the proceedings which ended in her losing her license. The psychiatrist found Crawley to have:

... a delusional disorder with the presence of narcissistic and borderline personality traits. ...

He also testified:

...she has persecutions of persecution and grandiosity and that she believes that she is being persecuted because she is special. ...

And if that isn't enough:

... Dr. Labins also testified that the Respondent (Dr. Carley)believes that her husband sodomized their son as part of a satanic ritual because she does not vaccinate and because she cures children with autism. ...

So if you ever wondered who was out there promoting vaccines as being evil, and mercury as causing autism, here is one prime example.

Unfortunately it's usually not the out and out loonies that sucker people in, but some of their psychologically slightly better balanced followers who do the most damage.

Joe is 211