Outdoor Worker Safety: Avoid Valley Fever Exposure


The California State Contractors License Board and California Department of Public Health warn that construction and other workers who disturb soil are at risk for contracting Valley Fever, and encourage employers to include protective measures in workplace health and safety plans. The Coccidioides immitis fungus lives in the soil in parts of California, particularly in the Central Valley, and in several southwestern U.S. states, and in Central and South America. Valley Fever is contracted by inhaling fungal spores that live in the dirt and that are stirred up by activity, including but not limited to construction, digging or driving, or working in dusty, wind-blown areas. Typically those who become infected experience pneumonia and flu-like symptoms.

Workers at higher risk for Valley Fever include wildland firefighters, construction workers, archaeologists, military personnel, and workers in mining, gas and oil extraction jobs. In 2007, 10 members of a 12-person construction crew excavating a trench developed Valley Fever (also known as coccidioidomycosis), an illness with pneumonia and flu-like symptoms. Seven of the 10 had abnormal chest x-rays, four had rashes, and one had an infection that spread beyond his lungs. Over 1000 Californians are hospitalized with Valley Fever every year. About 8 of every 100 people hospitalized die from the infection annually.

Although there is no vaccine against Valley Fever, the Department of Public Health suggests that employers and workers can take protective measures including but not limited to “incorporating the following elements into the company’s Injury and Illness Prevention Program and project-specific health and safety plans:
1. Determine if the worksite is in an area where Valley Fever is endemic (consistently present). Check with your local health department to determine whether cases have been known to occur in the proximity of your work area. See the map on page 2 to determine whether your company will be working in an endemic county.
2. Train workers and supervisors on the location of Valley Fever endemic areas, how to recognize symptoms of illness (see page 3), and ways to minimize exposure. Encourage workers to report respiratory symptoms that last more than a week to a crew leader, foreman, or supervisor.
3. Limit workers’ exposure to outdoor dust in disease-endemic areas. For example, suspend work during heavy wind or dust storms and minimize amount of soil disturbed.
4. When soil will be disturbed by heavy equipment or vehicles, wet the soil before disturbing it and continuously wet it while digging to keep dust levels down.
5. Heavy equipment, trucks, and other vehicles generate heavy dust. Provide vehicles with enclosed, air-conditioned cabs and make sure workers keep the windows closed. Heavy equipment cabs should be equipped with high efficiency particulate air (HEPA) filters. Two-way radios can be used for communication so that the windows can remain closed but allow communication with other workers.
6. Consult the local Air Pollution Control District regarding effective measures to control dust during construction. Measures may include seeding and using soil binders or paving and laying building pads as soon as possible after grading.
7. When digging a trench or fire line or performing other soil-disturbing tasks, position workers upwind when possible.
8. Place overnight camps, especially sleeping quarters and dining halls, away from sources of dust such as roadways.
9. When exposure to dust is unavoidable, provide NIOSH-approved respiratory protection with particulate filters rated as N95, N99, N100, P100, or HEPA. Household materials such as washcloths, bandanas, and handkerchiefs do not protect workers from breathing in dust and spores…”

They can also become vigilant about watching for warning symptoms, and seeking early medical attention if typical symptoms appear (between 7 and 21 days after breathing in spores) and include:
•Cough •Fever •Chest pain •Headache •Muscle aches •Rash on upper trunk or extremities •Joint pain in the knees or ankles •Fatigue
Additional Resources: California Department of Public Health; Centers for Disease Control and Prevention