Major grocery retailers serving dense urban areas such as New York, London and Paris are under increasing pressure to get product to consumers in the shortest possible time, as little as 15 minutes, and often for free. But there are downsides to the trend.

Food-borne illnesses can be deadly. Yet when people hear about a food recall — even for something serious like E.coli — they usually determine whether or not they recently purchased that item and move on, not stopping to consider what the situation implies about the U.S. food supply chain.