This bit jumped out:
Ian Roberts, a professor at the nutrition and public health intervention research unit at the London School of Hygiene and Tropical Medicine, began his career as a paediatric trauma doctor. "I saw lots of children hit by cars," he says, "and it really is awful." He describes these deaths as "kinetic energy disease" – a reference to the idea of mismatched masses in motion. When one of those masses is protected by metal casing, but the other isn't, it's clear who is more likely to be hurt.