A haboob's giant brown wall contains a lot more than desert dirt, according to air quality experts.

Next time you want to get close to this weather phenomenon, you should know plenty of icky stuff could be along for the dusty ride.

That includes manure and pesticides from agricultural land. The wind whipping across roads and highways could kick up brake dust and tiny pieces of tires. Spores beneath the desert crust could also go airborne, making people sick with Valley fever, which is a fungal lung infection.

VIDEO: Large wall of dust moves across southeast Valley

"There's quite a bit of research to try to look at what is the effect of Valley fever and how is it linked with these dust storms," said Ronald Pope, an atmospheric scientist at the Maricopa County Air Quality Department.

RELATED: 4 monsoon driving tips that could save your life

Air quality experts say the particles big enough to see, like dirt and sand, are mostly filtered out in your nose and throat, so they don't get lodged in your lungs.

Dust storms also have microscopic particles, which scientists call PM10. Those particles in sufficient qualities can be harmful, especially to people with respiratory illnesses.

RELATED: Get tested for Valley Fever for $45