In Episode 60 David discusses the dangers of ultrasound with Jim West, author of an annotated bibliography of research from China. Once Western countries, in particular the US, moved past the evidence that ultrasound was neither safe nor effective, research shut down, and the negative findings were forgotten. But in China, starting in the 1980s, and continuing until recently, research on the biological effects of ultrasound on the fetus was quite common, performing ultrasound on fetuses that were about to be aborted, to avoid ethical issues. This research lends evidence that the extremely high frequencies of ultrasound, and the ever increasing power, can cause cellular changes at the microscopic level. And there is some epidemiological evidence to suggest that there are increased risks of diseases like autism in babies that had the most ultrasounds while in the womb.