A PBS cameraman records footage of a discussion between environmental engineer Vic Etyemezian of the Desert Research Institute and NASA Dryden occupational health scientist Miriam Rodon-Naveira for a feature story on their Valley Fever research study to be aired on the PBS News Hour in June. (NASA / Beth Hagenauer) › View Larger Image
NASA's Dryden Flight Research Center is known for aircraft and science research, but a recent center-funded study is examining an air-borne disease found in California's Mojave Desert.
Microscopic spores found in the soil of the arid regions of California and Arizona can lead to a serious fungal infection called Valley Fever, also known as coccidioidomycosis.
Reported Valley Fever cases in the high desert portions of Los Angeles County known as the Antelope Valley increased 545 percent when comparing 2000 - 2003 (49 cases) to 2008 - 2011 (316 cases), according to Ramon E. Guevara, Ph.D., epidemiologist with the County of Los Angeles Department of Public Health.
The disease is contracted after tiny spores are inhaled into the lungs from disturbed soil. There is no vaccine for this non-transmittable disease. Although it can be debilitating, it is rarely fatal.
A large number of those who live in the arid Southwest may become infected when exposed to the spores, but do not notice symptoms. Others develop symptoms similar to the flu that can last for months. In extreme cases, the infection can spread from the lungs to other parts of the body.
Especially vulnerable are visitors or new residents of an area where Valley Fever is prevalent, such as the Antelope Valley area of the Mojave Desert about 100 miles northeast of Los Angeles. NASA Dryden, located on Edwards Air Force Base in that region, hosts hundreds of temporary contract employees or guest scientists who come to the center to conduct research using Dryden's aircraft.
"What makes the Antelope Valley significant is that it has the largest potential for population growth in Los Angeles County. In the Antelope Valley from 1996 to 2005, the correlation between the number of Valley Fever cases and the number of newly constructed privately owned buildings is 0.95, which is very strong as the perfect correlation is 1.00," Guevara added.
All NASA centers have identified strategies for dealing with potential negative effects of climate change and formed the Climate Adaptation Science Investigator (CASI) working group. This group is tasked with identifying climate-change risks – such as drought, flooding, hurricanes, wildfires – at each center and developing strategies intended to minimize the impact to NASA missions. Dryden's representatives are meteorologist Ed Teets and occupational health scientist Miriam Rodon-Naveira, who holds a doctorate in microbiology.
Teets and Rodon-Naveira continue research this year into the spread of Valley Fever by funding a scientist to gather soil samples in the region. Thomas Mace, retired NASA scientist and CASI member, procured original funding in 2012.
"NASA is enabling this research, hoping to provide the scientific community with data to better understand how climate increases or decreases outbreaks of Valley Fever," said Rodon-Naveira. "That information can then be translated and provided to public health communities so they can use the data to make more informed decisions concerning Valley Fever."
Antje Lauer, an assistant professor at California State University in Bakersfield, gathers soil samples at Edwards Air Force Base as part of the research to characterize the soil where the Valley Fever spores grow. (DRI / George Nikolich) › View Larger Image Antje Lauer, who has a Ph.D. in biology and is an assistant professor at California State University in Bakersfield, recently gathered soil samples from a variety of locations at Edwards Air Force Base with the goal of learning if one area held more Valley Fever spores than another. For example, is there an increase in the number of spores at the edge of a dry lake where moisture may have at times been greater than on the sloping hillside? A looming question is whether the current drought is increasing the number of Valley Fever cases when the dry soil is disturbed and releases the spores that are carried by desert winds.
"Antje Lauer's work is very important to public health as she and her team lead the research in characterizing the soil where the Coccidioides immitis fungus grows," commented Guevara. "Such information can contribute to strategies such as construction worker protection and population education."
The Dryden CASI working group members brought together Lauer, Vic Etyemezian, who approaches his work with a doctorate in civil and environmental engineering, and George Nikolich of the Desert Research Institute (DRI) in Las Vegas, as the type of research the groups were conducting was complimentary.
As part of a NASA Research Opportunities in Space and Earth Sciences (ROSES) grant studying climate change at Dryden, Etyemezian is researching how soil behaves at different wind speeds. The pair collected dust samples using a small portable wind tunnel creating a situation similar to what occurs in the desert when the dust blows. They also studied the plants in the area of dust sampling because soil in that area may react differently from that sampled away from vegetation.
Additional DRI research funded under NASA's Impacts of Climate Variability and Change on NASA Centers and Facilities Program grant includes development of regional climate projections for the Antelope Valley and characterization of the hydrology of the local watershed for the possibility of extreme storm events and flooding at Dryden. The latter included deploying meteorological sensors on and around Rogers Dry Lake.
Valley Fever also caught the attention of Public Broadcasting Services' News Hour producers who interviewed the researchers while they collected soil samples on the edge of Rosamond Dry Lake at Edwards in mid-May.
NASA Dryden is enabling the California State University – Bakersfield and the Desert Research Institute studies to gain more information about where this particular organism lives. The ability to determine the type of soil, wind levels and moisture content required to reproduce and spread Valley Fever spores may lead to a healthier population in the arid Southwest.