Robert A. Perkins

Biodegradation of dispersed oil in Arctic seawater at -1°C.

As offshore oil and gas exploration expands in the Arctic, it is important to expand the scientific understanding of arctic ecology and environmental impact to mitigate operational risks. Understanding the fate of oil in arctic seawater is a key factor for consideration. Here we report the chemical loss due to the biodegradation of Alaska North Slope (ANS) crude oil that would occur in the water column following the successful dispersion of a surface oil slick. Primary biodegradation and mineralization were measured in mesocosms containing Arctic seawater collected from the Chukchi Sea, Alaska, incubated at −1°C. Indigenous microorganisms degraded both fresh and weathered oil, in both the presence and absence of Corexit 9500, with oil losses ranging from 46−61% and up to 11% mineralization over 60 days. When tested alone, 14% of 50 ppm Corexit 9500 was mineralized within 60 days. Our study reveals that microorganisms indigenous to Arctic seawater are capable of performing extensive biodegradation of chemically and physically dispersed oil at an environmentally relevant temperature (−1°C) without any additional nutrients.

The acute toxicity of chemically and physically dispersed crude oil to key Arctic species under Arctic conditions during the open water season.

The acute toxicity of physically and chemically dispersed crude oil and the dispersant Corexit 9500 were evaluated for key Arctic species. The copepod Calanus glacialis, juvenile Arctic cod (Boreogadus saida), and larval sculpin (Myoxocephalus sp.) were tested under conditions representative of the Beaufort and Chukchi Seas during the ice-free season. The toxicity of 3 water-accommodated fractions (WAF) of Alaska North Slope crude oil was examined with spiked, declining exposures. A dispersant-only test was conducted with the copepod C. glacialis. Each preparation with oil (WAF, breaking wave WAF [BWWAF], and chemically enhanced WAF [CEWAF]) produced distinct suites of hydrocarbon constituents; the total concentrations of oil were lowest in WAF and highest in CEWAF preparations. The relative sensitivity for the different species and age classes was similar within each WAF type. Median lethal concentration values based on total petroleum hydrocarbons ranged from 1.6 mg/L to 4.0 mg/L for WAF and BWWAF treatments and from 22 mg/L to 62 mg/L for CEWAF. For Corexit 9500 exposures, median lethal concentration values ranged from 17 mg/L to 50 mg/L. The differences in the relative toxicity among the accommodated fractions indicated that the majority of petroleum hydrocarbons in the CEWAF are in less acutely toxic forms than the components that dominate the WAF or BWWAF. Further evaluation showed that the parent polycyclic aromatic hydrocarbon compounds, specifically naphthalene, were highly correlated to acute toxicity. Environ Toxicol Chem 2013;32:2284–2300.

A COLD-WEATHER SPECIES' RESPONSE TO CHEMICALLY DISPERSED FRESH AND WEATHERED ALASKA NORTH SLOPE CRUDE OIL

ABSTRACT The University of Alaska Fairbanks (UAF) joined the Chemical Response to Oil Spills: Ecological Effects Research Forum (CROSERF) in 1997. In 1998 and 1999, UAF tested the toxicity of: (1) ...

Toxicity of dispersed and undispersed, fresh and weathered oil to larvae of a cold-water species, Tanner crab (C. bairdi), and standard warm-water test species

Abstract There are many methods in current use for testing the toxicity of discharges to marine waters. Standard tests and species established by the Environmental Protection Agency and other regulators are commonly used. None of these commonly used test procedures are conducted with cold seawater or species typical of northern latitudes. This paper reports on the toxicity testing of oil and dispersed oil, both fresh and weathered, to larvae of a cold-water species, the Tanner crab (Chionocetes bairdi), and compares these results to those observed with a standard warm-water test species, the saltwater mysid (Mysidopsis bahia). The method of reporting the exposure dose is based on: loading rate (LR), concentrations of volatile organic analytes (VOA, C6–C9), total petroleum hydrocarbon (TPH, C10–C36), or on total hydrocarbon content (THC, C6–C36). Different conclusions result, depending on the reporting method. These differences are chiefly due to the greater accommodation of VOA in the colder water and the paucity of TPH in undispersed cold-water solutions.

Evaluation of Public and Worker Exposure Due to Naturally Occurring Asbestos in Gravel Discovered During a Road Construction Project

During a repair and reconstruction project of an unpaved highway in a remote region of Alaska, workers discovered, after construction had commenced, that the materials used from a local material site contained asbestos (variously described as tremolite or actinolite). The regional geology indicated the presence of ultramafic rock, which often contains asbestos. Evaluation of asbestos exposure to workers, their equipment, and living quarters was required, as was the possible future exposure of workers and the general public to asbestos already used in the roadway construction. In addition, a decision was needed on whether to use materials from the contaminated site in the future. Of the almost 700 breathing zone air monitoring samples taken of the workers, 3% of the samples indicated exposures at or near 0.1 f/cc by the National Institute for Occupational Safety and Health (NIOSH) 7400 phase contrast microscopy (PCM) procedure. Thirty-six of the PCM samples underwent transmission electron microscopy (TEM) analysis by the NIOSH 7402 procedure, which indicated that about 40% of the fibers were asbestos. After classifying samples by tasks performed by workers, analysis indicated that workers, such as road grader operators who ground or spread materials, had the highest exposures. Also, monitoring results indicated motorist exposure to be much less than 0.1 f/cc. The design phase of any proposed construction project in regions that contain ultramafic rock must consider the possibility of amphibole contamination of roadway materials, and budget for exploration and asbestos analysis of likely materials sites.

Toxicity of Physically and Chemically Dispersed Oil to Selected Arctic Species

ABSTRACT A joint industry program was formed to investigate the toxicity of chemically and physically dispersed oil to valuable ecosystem components of the Beaufort and Chukchi Seas, Calanus glacialis (copepod) and Boreogadus saida (arctic cod). In 2009 and 2010 these species plus a sculpin (Myoxocephalus sp.) were collected from the Beaufort and Chukchi Seas near Barrow, Alaska. Toxicity tests were completed using procedures previously developed by the CROSERF project but conducted at temperatures representative of the Beaufort and Chukchi Seas. Tests were performed using fresh Alaska North Slope (ANS) crude oil. Three types of dispersed oil were tested: physically dispersed oil, chemically dispersed oil, and oil physically dispersed under increased mixing energy conditions. A physical dispersion treatment with increased mixing energy was developed because low energy mixing conditions did not produce realistic dispersion. Spiked exposure toxicity testing was used to simulate environmentally relevant expo...

Asbestos Release from Whole-Building Demolition of Buildings with Asbestos-Containing Material

The whole-building demolition method, which entails one-or two-story buildings pushed down by heavy equipment, loaded into trucks, and hauled away, is generally the most cost-effective means to remove small buildings. For taller buildings, a crane and wrecking ball may be used initially to reduce the height of the building. Demolitions might release asbestos fibers from friable asbestos-containing material (ACM). Fibers also might be released from nominally nonfriable ACM (Categories I and II nonfriable ACM) if it becomes friable after rough handling throughout the whole-building demolition process. This paper reports on asbestos air monitoring from two demolition projects involving ACM. In one building, Category II nonfriable ACM was present because it could not be removed safely prior to demolition. Both projects had large quantities of gypsum wallboard with ACM joint compound and ACM flooring. One building had large quantities of ACM spray-on ceiling material. During the demolitions personal air monitoring of the workers and area air monitoring downwind and around the sites were conducted. The monitoring found the concentrations of fibers detected by phase contrast microscopy were generally well below the permissible exposure limits (PEL) of workers. Electron microcopy analysis of samples at or near the PEL indicated most of the fibers were not asbestos, and the actual asbestos exposure was often below the detection limit of the procedure. The buildings were kept wet with fire hoses during the demolition and that required large quantities of water, 20,000–60,000 gal/day (75–225 m3/day). Earlier studies found little asbestos release from buildings containing only nonfriable ACM demolished by this method. This project found a negligible release of asbestos fibers, despite the presence of nonfriable materials that might become friable, such as ACM joint compound and spray-on ACM ceiling coating.

Biodegradation of Oil and Dispersed Oil by Arctic Marine Microorganisms

As oil exploration and shipping routes expand in Arctic regions, the potential for oil to enter these cold water environments increases. Therefore it becomes important to understand how the indigen...

Toxicity of Dispersants and Dispersed Oil To An Alaskan Marine Organism

ABSTRACT The University of Alaska Fairbanks (UAF) conducted toxicity assays on Alaskan tanner crab larvae (Chionoecetes bairdi) using the oil dispersant Corexit 9500, Alaska North Slope (ANS) crude...

From declared asset retirement obligations to a decommissioning cost estimate for onshore crude oil fields in Nigeria

As in most mature crude oil producing regions, asset divestment has commenced in Nigeria. Decommissioning and associated environmental liabilities are expected to become important problems requiring attention. Public and government engagement on decommissioning will be ineffective without information on cost of decommissioning liabilities, which are held confidential by oil companies. This study demonstrates a method to determine generic aggregate cost of decommissioning liabilities for Nigeria onshore fields, using non-proprietary data from annual financial reports of operating companies in Nigeria. The results can be used as basis for negotiation with operators and to help government in preparation for decommissioning risk.