Cal/OSHA has issued serious health and safety citations to Underground Construction Co., Inc. of Benicia after two of its employees contracted Valley Fever. The workers were exposed to the fungal disease while using hand tools to dig trenches in Kings, Fresno and Merced counties—areas where the soil is known to contain harmful spores that cause the infection.

“When soil is disturbed by activities such as digging, driving, or high winds, Valley Fever spores can become airborne and potentially be inhaled,” said Cal/OSHA Chief Juliann Sum. “Without the proper training, protection and mitigation procedures, workers are likely to be exposed and get sick.”

Symptoms, severity

Cal/OSHA was notified in September 2018 that the employees were hospitalized after being diagnosed with Valley Fever, also known as Coccidioidomycosis. Symptoms of the disease are similar to the flu and include fatigue, shortness of breath and fever. Severe cases can cause serious lung problems.

The workers were tasked with digging trenches up to 5½ feet deep to allow access to gas pipelines for maintenance. Dust was not controlled, and the workers did not wear any respiratory protection. Exposure to the disease could have occurred in any one of the three counties where the fungal spores are known to be endemic.

Cal/OSHA’s investigation found that Underground Construction Co., Inc. did not evaluate the hazard of performing digging work in areas known to contain the coccidioides fungal spores. The employer did not suppress or control harmful dusts and failed to provide employees with respiratory protection. Cal/OSHA issued three citations to the employer with $27,000 in proposed penalties.

Since 2017, Cal/OSHA has cited 12 businesses for work-related Valley Fever.

How spores go airborne

Valley Fever is caused by a microscopic fungus known as Coccidioides immitis, which lives in the top two to 12 inches of soil in many parts of the state. When soil is disturbed by digging, driving or high winds, fungal spores can become airborne and may be inhaled by workers who are not protected. While the fungal spores are most likely to be present in the soils of the Central Valley, they may also be present in other areas of California. Cal/OSHA’s Valley Fever informational page provides detailed information including resources for workers and employers.

Tips for reducing the risk of Valley Fever exposure include:

  • Determine if a worksite is in an area where fungal spores are likely to be present.
  • Adopt site plans and work practices that minimize the disturbance of soil and maximize ground cover.
  • Use water, appropriate soil stabilizers, and/or re-vegetation to reduce airborne dust.
  • Limit workers’ exposure to outdoor dust in disease-endemic areas by (1) providing air-conditioned cabs for vehicles that generate dust and making sure workers keep windows and vents closed, (2) suspending work during heavy winds, and (3) providing sleeping quarters, if applicable, away from sources of dust.
  • When exposure to dust is unavoidable, provide approved respiratory protection to filter particles.
  • Train supervisors and workers in how to recognize symptoms of Valley Fever and minimize exposure.