Weatherwatch: how dust storms heighten risk of Valley fever

US scientists develop system using a cake tin and marbles to forecast areas posing biggest health threat

The Roman writer Vitruvius wrote of an unhealthy wind blowing off the city's marshlands, bringing sickness. While this ancient miasmal theory of infection was superseded by germ theory, researchers have found that dust storms really can spread pathogens.

Scientists from George Mason University, Virginia, are studying dust storms in the south-western US and their connection with Valley fever, a fungal disease that kills hundreds of people every year.