Known commonly as yellow dust by most of the foreign community, it is basically inhalable particles that originate from the dry desert regions of China and Mongolia. There has been yellow dust coming from these regions to Korea for many generations. However, due to the deforestation that has occurred in Mongolia and China, along with the increased industrialization and resulting pollution in China, the yellow dust storms have been occurring with increasing frequency and with greater and greater negative effects. For the past few years, the dust storms often carry oxides (aluminium, calcium, iron, magnesium, potassium and silicon) and toxic waste thus increasing the risks of respiratory and skin reactions.
Although they occur mainly in Spring (March, April, May), yellow sand events are now being reported in all seasons, including winter. Some years are worse than others. It takes on average 2 or 3 days for a dust storm to reach Korea. The first yellow dust report in 2015 occurred in February with readings hovering betweenHazardous and Very Unhealthy.