A recent study by researchers at  Washington University School of Medicine in St. Louis   found certain fungi in soil can cause a significant number of serious lung infections in 48 out of 50 states and the District of Columbia, including many areas long thought to be free of deadly environmental fungi. Histoplasma  is one of the three main  species  of soil fungi that cause lung infections in the U.S. Historically,  Histoplasma  was found in the Midwest and parts of the East,  Coccidioides  in the Southwest, and  Blastomyces  in the Midwest and the South. But a growing number of case reports and anecdotes suggest that all three have expanded out of their traditional ranges in recent decades. People develop fungal lung infections after breathing in spores from fungi in the soil. The spores become airborne when the ground is disturbed by farming, landscaping, construction, or even just by people walking around in fungi-rich environments such as caves. Most healthy adults and children