| Sound waves have an impact. Too loud and it can permanently damage your hearing. What level of audio volume is safe? Water has an impact on your body. Drink too much and it can harm you. What amount of water is safe? etc., etc. The technology enables us to learn and prevent so many problems, that to write it off just because at extreme levels it can be harmful is foolish. And it's fearmongering to make that claim without evidence. See the summary here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262273/ > The first mention that ultrasound could be used to produce images of the foetal head was probably in a lecture given by Ian Donald in 1959. Since that time, the use of ultrasound in obstetrics has grown rapidly, and has a generally accepted excellent safety record. However, it is impossible to prove zero risk, and the absence of evidence of harm should not be taken as evidence of absence of harm. The epidemiological evidence that exists is reassuring as to the safety of routine ultrasound scanning, but of necessity it only includes subjects who were imaged with devices that were state of the art at the time (mostly early 1980s). No pulsed Doppler or colour flow examinations are included, and the output from modern ultrasound scanners is considerably higher today than it was at that time. It is, therefore, essential to remain vigilant, and to assess new technologies and applications from a safety aspect as they arise. So TL;DR: Ultrasound is safe, the benefits outweigh the risks by a large margin, and we should always insist that Ultrasound, and any modern medical technology is held to rigorous scientific testing standards. |