It’s that time of year when increased temperatures create the potential for a type of air pollution you can’t see or smell. Ozone but can be deadly to asthmatics, children and seniors with respiratory problems. And just last week, the valley experienced it’s first ozone Health Watch of the year. Twenty-nine were issued last year. Holly Ward, public information officer for the Maricopa County Air Quality Department, talked to KJZZ's Paul Atkinson about the problem and what can be done about it.