PALM DESERT, Calif. -

Levels of particulate matter in the Coachella Valley were high enough to cause health problems Tuesday morning.

Particulate matter is usually caused by blowing dust and sand and the valley is experiencing strong winds putting a lot of dust into the air.

As of 9 p.m. Monday night, the Air Quality Index at the valley's two reporting stations for particulate matter was 159.  Levels above 151 are considered unhealthy and everyone may begin to experience health effects.  Members of sensitive groups may experience more serious health effects.

As of 5 a.m. Tuesday morning, the Air Quality Index was 152, still in the range of unhealthy.