… Dust storms are common in the [Coachella Valley] region, which is home to around 500,000 people.  A major source of that dust is a huge lake that’s steadily drying up. Spanning some 343 square miles (888 square kilometers), the Salton Sea is California’s largest lake. But it’s rapidly shrinking. When winds sweep over the exposed lakebed, they pick up the parched sediment, producing harmful dust storms. Children living near the lake have been found to have disproportionately high rates of asthma. One study that followed more than 700 primary-school aged children over a number of years found that 24% reported having the condition — far higher than the national rate of about 7% for boys and 5.5% for girls. Over 70% had allergies — more than three times the national average.