Effects of Ultrasound - Possible Cause of Autism?

I have become somewhat alarmed at the rate of increase of autistic children.  No one seems to know why the number of autistic children seems to be rising dramatically. 

It could be a disease.  It could be hereditary.  It could be something in the environment.  A lot of attention was recently focused on vaccines and the possible implication of thimerosal in the vaccines.  There is apparently no correlation between thimerosal and autism according to recent studies.  Thimerosal is a preservative that, according to internet sources, has been used in vaccines since the 1930s.  Unless autism is a communicable disease, I should think that we should be looking for something introduced more recently...

The use of prenatal ultrasound imaging is something that was not in use until relatively recently.  Ultrasound has MANY biological effects:

a   Selective heating or burning of nerves and loss of their ability to conduct nerve impulses. (Laboratory animals)
b.  Heating of bone-tissue interfaces. (Humans, laboratory animals)
c.  Tinnitus (ringing of the ears.) (Humans)
d.  Death of mice and rats. (Laboratory animals)
e.  Clotting of blood. (Laboratory animals)
f.  Burning of tissue. (Laboratory animals)
g.  Hemorrhage in the gastro-intestinal tract. (Laboratory animals)
h.  Permanent paralysis. (Laboratory animals)
i.  Cataracts on lens and cornea of eyes. (Laboratory animals)
j.  Bone growth inhibition. (Laboratory animals)
 

Some of these effects are much more noticeable at high power levels but some of them occur even at minute power levels.  I wonder if anyone has an answer to the following questions:

  1. What is the percentage of autistic children whose mothers allowed ultrasound imaging to be done on them?
  2. What is the percentage of autistic children whose mothers DID NOT allow ultrasound imaging to be done on them?

An FDA Symposium in 1977 contained a paper on blood coagulation caused by ultrasound at power levels of 65 milliWatts. A question was asked regarding the lowest power level that could lead to coagulation and the answer was "No specific threshold has been set that I know of."

The allowable power levels of ultrasound for imaging seems to be going up to support fancier imaging.  The maximum allowed power level used to be 94 milliWatts per square centimeter and now it is 720 milliWatts per square centimeter according to information on http://www.centrus.com.br/DiplomaFMF/SeriesFMF/doppler/capitulos-html/chapter_02.htm:

"In revising its regulations in 1993, the FDA 15 altered its approach to ultrasound safety. The new regulations combine an overall limit of I-SPTA of 720 mW/cm 2 for all equipment with a system of output displays to allow users to employ effective and judicious levels of ultrasound appropriate to the examination undertaken. The new regulations allow an eight-fold increase in ultrasound intensity to be used in fetal examinations."

A more recent NIH Public Access publication, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2390856/, contains the following statement:

"Thus, the net effect of the 1992 change in guideline limits was to increase the SPTA intensity allowed for obstetrical ultrasound from 94 mW/cm2 to 720 mW/cm2..."

I copied part of a book on ultrasound that was in the Pentagon Library in 1979.  I recently acquired a copy of that book: "Ultrasonic Engineering" by Alan E Crawford, Butterworths Scientific Publications, London, 1955.

This was on p 297:

"If the femur of a dog is exposed to an average intensity of 2 Watts per square centimeter the temperature is raised 40 Degrees Centigrade in two minutes."

Assuming the heating effect is linear (and I don't know if it is) then 750 mW/cm2 would heat the femur (750/2000) x 40 = 15 degrees C or 59 degrees F. Normal body temperature of a fetus is presumably 98.6 F so this could raise the temperature to 157.6 degrees F.

Now it is known that ultrasound primarily heats nerve/tissue interfaces and bone/tissue interfaces so the above temperature increase would probably not involve the entire fetus but it certainly might damage nerves in the developing brain similar to what was demonstrated by experiments on developing mouse neurons when they are exposed to ultrasound.

Same book, p 289:

Eggs of Drosophila melanogaster were treated in water at a uniform intensity of about 0.3 to 0.5 Watts per square centimeter and at a frequency of 1 Mc/s [Mhz].  This intensity is insufficient to cause the disruptive effect of cavitation and its associated chemical effects, but a streaming action is produced within the egg so that nuclei, cytoplasm and yolk are left in abnormal positions.  The treatment time was 30 seconds on the newly laid eggs, and after irradiation, the eggs were incubated.  On hatching, it was found that abnormal spatial relationships between organs or a complete absence of  certain organs, had been produced.  The involution of the head and hypodermis was most marked.  Differentiation of cells aso occurred; for example, the nervous system was differentiated into ganglia and fibres and elongation of muscle cells sometimes took place without fusion.


In 1979, I was an Air Force Major working in the Pentagon.  Everything was fine until new ultrasonic motion detection systems were installed in our office/vault.  I, and others, then began experiencing some unusual effects which I believe were the result of continuous exposure to the ultrasound emissions.  There is of course no "proof" but my research into this area greatly raised my concern and I was eventually successful in my battle to have a switch installed that would turn off the emitter during the time we were working in the office.  (The motion detectors were only used when everyone had gone home so the emitters did not have to be running during working hours.)

I found the memo I wrote at that time.  I transcribed it and have included it here: 
"Ultrasonic Radiation from ADT Motion Detectors"

Also a follow-up memo describing my conversation with FDA officials at that time:
"Conversation with FDA Officials Concerning Ultrasonic Effects"

I also have excerpts from the "SYMPOSIUM on BIOLOGICAL EFFECTS and CHARACTERIZATIONS of ULTRASOUND SOURCES", Proceeding of a Conference held in Rockville, Maryland, June 1-3, 1977.

Also excerpts from FDA Workshop Proceedings, Interaction of Ultrasound and Biological Tissues, Sept 1972.
The summary included "CHANGES FOR WHICH MECHANISMS ARE NOT KNOWN" which included the following:
  1. Decrease in the number of glycogen granules.
  2. Alteration of mitochondria.
  3. Destruction of lysomes.
  4. Change in transport across membranes.
  5. Changes in electrophoretic mobility.
  6. Ultrastructural changes in muscle.
  7. Changes in cell division processes and other inherited effects.
  8. Structural changes within the inner ear.
There is also the following statement:
"Probably the lowest reported intensity threshold for cellular damage is the value of 1 milliWatt per square centimeter reported by Hawley and Dunn for effects on rotifers in the high frequency range 200-600 MHz; the possibility of a resonant effect is noted."

From:  http://www.wired.com/wired/archive/9.12/aspergers_pr.html:
"Studies have shown that if one identical twin is autistic, there's a 90 percent chance that the other twin will also have the disorder."
If ultrasound were the cause and both were exposed to ultrasound at the same time, isn't that what one would expect? 

Could there be a critical time-window during gestation when ultrasound causes a problem?

Anyway, enough to make me wonder.  Personally, if I had a pregnant wife, I would STRONGLY advise her to avoid exposing the fetus to ultrasound.   (My mother was a nurse.  She said she wouldn't even take an aspirin while she was carrying me...  Just not worth the risk...)

Anybody remember the Buster Brown Shoe Store Fluoroscopes in the 1950's?   You could watch your toe bones wiggle inside your shoes in real-time via the magic of X-rays!  Was great fun!  Wonder how much radiation I received from those machines?  Anybody wonder why those machines are no longer available?  (The good thing was that Buster Brown could remove them without fear that they would be providing support for some lawsuit against them - otherwise they might still be in place?)

Some related links:

http://www.medicalnewstoday.com/articles/49000.php

http://bestyoucanbe.blogspot.com/2006/08/ultrasound-neuronal-migration-and.html

http://www.associatedcontent.com/article/54596/prenatal_ultrasound_exams_linked_to.html:
"We were having a working lunch one afternoon when, purely by accident, someone placed an overhead projection transparency that charted the yearly increase in the number of ultrasound exams on top of another transparency that graphed the increasing number of children diagnosed with the psychological criteria for either Asperger's Syndrome or Autism. As you can imagine, we were shocked to learn that these graphs were identical" Dr. Wassah-Boolphrogg said.

http://www.midwiferytoday.com/articles/ultrasoundrodgers.asp
"Statistics on the increase of autism worldwide among industrialized nations show that it has emerged in just the last few decades across vastly different environments and cultures. What do countries and regions with climates, diets and exposure to known toxins as disparate as the US, Japan, Scandinavia, Australia, India and the UK have in common? No common factor in the water, air, local pesticides, diet or even building materials and clothing can explain the emergence and relentless increase in this serious, life-long neurodevelopmental disorder.

What all industrial countries do have in common is the quiet yet pervasive change in obstetrical care: All of them use routine prenatal ultrasound on pregnant women.

In countries with nationalized healthcare, where virtually all pregnant women are exposed to ultrasound, the autism rates are even higher than in the US, where due to disparities in income and health insurance, some 30 percent of pregnant women do not yet undergo ultrasound scanning."

http://www.yale.edu/opa/newsr/06-08-07-01.all.html
“Proper migration of neurons during development is essential for normal development of the cerebral cortex and its function,” said Pasko Rakic, M.D., chair of the Department of Neurobiology and senior author of the study. “We have observed that a small but significant number of neurons in the mouse embryonic brain do not migrate to their proper positions in the cerebral cortex following prolonged and frequent exposure to ultrasound.”

http://www.newscientist.com/article.ns?id=dn1670