Results of analyses of fur samples from the San Joaquin Kit Fox and associated soil and water samples from the Naval Petroleum Reserve No. 1, Tupman, California

Abstract

assisted in sample preparation, data preparation, and the framing of hypotheses. Tom O'Farrell provided advice and encouragement. vii ABS'TRACT The purpose of this study was to determine whether analysis of the elemental content of , fur from San Joaquin kit foxes (Vulpes macrotis mutica) and of water and soil from kit fox habitats could be used to make inferences concerning the cause of an observed decline in the kit fox population on Naval Petroleum Reserve No. 1 (NPR-1). Fur samples that had been collected previously from NPR-1, another oil field (NPR-2), and two sites with no oil development (Camp Roberts and Elkhorn Plain) were subjected to neutron activation analysis. In addition, soil samples were collected from the home ranges of individual foxes on NPR-1 and Camp Roberts and from undisturbed portions of major soil types on NPR-1 and subjected to neutron activation analysis. Finally, wastewater samples were collected from tanks and sumps on NPR-1 and analyzed. Statistical analyses revealed that most of the variance in elemental content of fur was attributable to differences among sites. Most elemental concentrations in fur were highest at Camp Roberts and lowest on the undeveloped portions of NPR-1. Fur concentrations were intermediate on the developed oil fields but were correlated with percent disturbance and with number of wells on NPR-1 and NPR-2. The fact that most elements covaried across the range of sites suggests that some pervasive source such as soil was responsible. However, fur ., concentrations were not correlated with soil concentrations. This suggests that differences in bioavailability or in soil intake were responsible for the variance in that set of elements. Some elements that are associated with oil development do not fit this pattern. Arsenic, which was used as a biocide, is found at higher concentrations on NPR-1 and NPR-2 than other sites and, in three fur samples from those sites, at concentrations equal to hair concentrations associated with toxic effects in humans. However, the highest concentration is from a fox that lived on the periphery of NPR-1 outside the developed areas. Barium, which is a major component of drilling fluids, was also higher in fur samples from the oil fields than from other sites and was significantly correlated with the number of wells in the foxes' home range. However, the differences among sites were small and, except for comparisons of undeveloped NPR-1 with other sites, were not statistically significant. Vanadium, which is associated with petroleum, occurred at higher average concentrations in fur from oil fields than any site except Elkhorn Plain, ali of the top ten concentrations were from NPR-1, and concentrations were correlated with the number of wells. Although the differences among sites in vanadium concentrations were relatively small, the range across individuals was relatively large, which is consistent with exposure of a few air ix jlkl, , holds. However, the relationships between exposure levels and fur concentrations are stronger for no...

Systematic Review and Weight of Evidence Are Integral to Ecological and Human Health Assessments: They Need an Integrated Framework

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An Independent Scientific Assessment of Well Stimulation in California Volume II: Potential Environmental Impacts of Hydraulic Fracturing and Acid Stimulations

“…In the limited studies available of ecological impacts of oil field activity in California, there are a few documented cases of giant kangaroo rats, blunt-nosed leopard lizards and San Joaquin kit foxes drowning in accidental spills of oil and oil-laden wastewater (Kato and O'Farrell, 1986;O'Farrell and Kato, 1987). Suter et al (1992) examined the elemental content of fur samples from San Joaquin Kit Foxes inhabiting two oil fields (one active, one inactive), and two control areas. They found that foxes on the developed sites had elevated levels of a number of elements which may be attributable to oil field materials.…”