Written as a retort to the Yale study by Ang, et all in 2006 which detected brain growth abnormalities after ultrasonic exposure…
These fellows discuss some of the dissimilarities between the Ang study using mice and actual prenatal conditions. Although it is true that the Ang study’s results are not perfectly linear, such can be expected from such a study.
* Ang noted ultrasound to cause brain growth problems at intensities an order of magnitude or so lower than modern intensities. (meaning modern prenatal ultrasound is stronger, and may have more impact)
* The thermal and mechanical indices are not great guestimations, meaning that US scanners do not accurately report risks.
* Rats are not perfect models for human brains.
I have a comment about some of the response, too. In this paper they discuss later-trimester fetal skulls to be stronger — while it is true that they do become more developed, the fetal skull is pretty soft, still.
In fact, it has similar acoustic indices as water. Adult skulls that are well ossified are much better acoustic absorbers.
I also found it interesting that Republican Joe Pennacchio had attempted to introduce legislation into the investigation of ultrasound and autism.
These are not new concerns.