Dirty seasonal fog could put a damper on holidays

摘要

The dirty fog hanging over Salt Lake Valley, Utah, may stick around for the holidays.rnThe seasonal Wasatch Front fog, which causes coughing spells and poor driving conditions,rncontributed to unhealthy levels of air pollution throughout the day yesterday.rnThe fog is triggered by a temperature inversion, in which warm air passes over valleys, trappingrnthe pollutants in cold air below. And no storms that could provide relief are expected for at leastrnthe next couple of weeks.