Thousands of residents across a part of California , including communities in San Bernardino, Orange, and Riverside counties, have received an air quality alert from the National Weather Service (NWS) and have been advised to stay inside through Sunday, as particle pollution in the atmosphere has reached " harmful levels ." According to the NWS, the elevated level of particle pollution across an area in California is due to windblown dust. Particle pollution can also come from smokestacks and