Strong winds picking up loose particles of dirt, dust, sand and other small debris cause dust storms. They occur in deserts, but also in drought-stricken areas, especially areas that are overgrazed or tilled, anywhere that is very dry and has loose soil. Dust storms are a major problem in some regions where they reduce visibility, damage machinery and even negatively alter the landscape.
Dust storms can be a major and widespread problem where they occur, stretching for hundreds of miles and up to 10,000 feet into the air. Dust storms often strike without warning, driven by winds of at least 25 miles per hour, and often cause car accidents and other problems from low visibility in their wake. In the long term, dust storms can even strip farmland of its topsoil, ruining its ability to support crops. Outdoor animals such as livestock are also often adversely affected.
While being inside does provide some protection from dust storms, even in urban areas they can be a problem. Their high winds cause power outages, and the dust gets everywhere, even through the ventilation systems in buildings, damaging computers and other sensitive electronics. The lightest particles in dust storms can be carried for thousands of miles, carrying dust from Africa all the way to South America, for instance.