Uh Oh: Valley Fever Outbreak Linked to Solar Development

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Fungal growth in lung tissue from valley fever | Photo: Centers for Disease Control/Flickr/Creative Commons License

Valley fever, a respiratory infection spread by fungal spores that live in soil, has been diagnosed in 28 workers at two San Luis Obispo solar project construction sites. According to a report in the Los Angeles Times, the stricken workers were employed at the California Valley Solar Ranch and Topaz Solar Farm, which occupy the arid Carrizo Plain in the eastern part of the county.

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According to the Times' Julie Cart, epidemiological investigators from SLO County, the state's Department of Public Health, and the California Division of Occupational Safety and Health (CalOSHA) visited the sites earlier this year to investigate the outbreak. Though Cart says officials were unwilling to release details about individual victims, citing health privacy rights, no life-threatening cases were reported.

Valley fever, aka coccidioidomycosis, is rampant in the San Joaquin Valley and only slightly less so in the deserts of California. The state accounts for a plurality of the cases of valley fever, and half of the nation's fatalities.

The disease, which can be mistaken for a mild flu but which is fatal in about one percent of cases, is spread when aridland soils are disturbed, releasing the spores of fungi in the genus Coccidioides. Dormant when the soil is dry, Coccidioides fungi grow networks of spore-generating tissue throughout the soil when it rains. Ordinarily, the spores pose little threat to human health. When soil is disturbed by plowing or construction activity, though, and the spores are released into the air, they pose a health hazard to anyone breathing them in.

The 550-megawatt Topaz Solar Farm is owned by MidAmerican Solar, which just launched construction on Antelope Valley Solar I and II in the high desert west of Rosamond. The 250-megawatt California Valley project is being built by First Solar, whose Antelope Valley Solar Ranch near Lancaster was just ordered to stop construction due to fugitive dust coming off that construction site and blowing into downtown Lancaster.

Valley fever is more prevalent in the Central Valley because the soils there are regularly disturbed by plowing, but as the pace of development increases in California's deserts we can likely expect an increase in the incidence of valley fever. People without access to health care are far more susceptible to its dangers, as are people with depressed immune systems. Some populations seem to possess greater genetic susceptibility to the disease. As those populations happen to include African Americans, Mexican Americans, and some Asian-Pacific Islanders, a potential increase in valley fever constitutes a serious environmental justice issue.

Environmental groups such as Basin and Range Watch do regularly bring up the topic of valley fever and its potential health and social impacts when discussing utility-scale energy development in the arid southwest, but the green movement that has supported projects like Topaz and California Valley has been largely silent on the projects' potential public health impacts. It may be that disadvantaged "downwinders" exposed to valley fever will turn out to be another, potent constituency that advocates of big renewables will have to address.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

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