Gregory W. Patton

Atmospheric monitoring of organic pollutants in the Arctic under the Arctic Monitoring and Assessment Programme (AMAP): 1993-2006.

Continuous and comparable atmospheric monitoring programs to study the transport and occurrence of persistent organic pollutants (POPs) in the atmosphere of remote regions is essential to better understand the global movement of these chemicals and to evaluate the effectiveness of international control measures. Key results from four main Arctic research stations, Alert (Canada), Pallas (Finland), Storhofdi (Iceland) and Zeppelin (Svalbard/Norway), where long-term monitoring have been carried out since the early 1990s, are summarized. We have also included a discussion of main results from various Arctic satellite stations in Canada, Russia, US (Alaska) and Greenland which have been operational for shorter time periods. Using the Digital Filtration temporal trend development technique, it was found that while some POPs showed more or less consistent declines during the 1990s, this reduction is less apparent in recent years at some sites. In contrast, polybrominated diphenyl ethers (PBDEs) were still found to be increasing by 2005 at Alert with doubling times of 3.5 years in the case of deca-BDE. Levels and patterns of most POPs in Arctic air are also showing spatial variability, which is typically explained by differences in proximity to suspected key source regions and long-range atmospheric transport potentials. Furthermore, increase in worldwide usage of certain pesticides, e.g. chlorothalonil and quintozene, which are contaminated with hexachlorobenzene (HCB), may result in an increase in Arctic air concentration of HCB. The results combined also indicate that both temporal and spatial patterns of POPs in Arctic air may be affected by various processes driven by climate change, such as reduced ice cover, increasing seawater temperatures and an increase in biomass burning in boreal regions as exemplified by the data from the Zeppelin and Alert stations. Further research and continued air monitoring are needed to better understand these processes and its future impact on the Arctic environment.

Polycyclic aromatic and organochlorine compounds in the atmosphere of northern Ellesmere Island, Canada

In February–April 1988 we collected air samples at Alert in the Canadian Arctic (82.5°N, 62.3°W) to determine the types, concentrations, and vapor-particle relationships for polycyclic aromatic hydrocarbons (PAH) and oxygenated compounds, Organochlorine (OC) pesticides, and polychlorinated biphenyls (PCB). Samples were taken using a glass fiber filter-polyurethane foam train and were analyzed by capillary gas chromatography using mass selective and electron capture detection. PAH and oxygenated compounds included dibenzofuran, biphenyl, fluorene, phenanthrene, 9-fluorenone, fluoranthene, benzofluoranthenes, pyrene, chrysene, benzopyrenes, indeno[cd]pyrene, benzo[ghi]perylene, 2-methyl phenanthrene, benz[a]anthracene, and anthracene (given in order of relative abundance, highest to lowest). OC compounds included hexachlorocyclohexanes (HCH), hexachlorobenzene, pentachlorobenzene, PCB, polychlorocamphenes, chlordanes, and the dichlorodiphenyl-trichloroethane (DDT) group (given as above). The concentration ratios of α-HCH/γ-HCH (5.2–9.8) and trans- to cis-chlordane (0.78–1.29) are reported. Compounds having estimated liquid-phase saturation vapor pressure (pL0) ≥ 10-3 Pa at the average sampling temperature (245 K) were almost entirely gaseous. Those from 10-6 ≤ pL0 ≤ 10-3 Pa were distributed between the particle and gas phases, whereas little or no gaseous component was evident for compounds having pL0 ≤ 10-6 Pa. The particle-vapor distribution of PAH and OC compared favorably to the Junge-Pankow model.

Survey of Radiological and Chemical Contaminants in the Near-Shore Environment at the Hanford Site 300 Area

This updates the original report by correcting some errors and adding new information. This assessment of the 300 Area was completed to identify any contamination present and determine if it could present a risk to humans and plant and animal life. The assessment characterized the radiological and chemical conditions existing in the near-shore environment of the Columbia River at the 300 Area by collecting water, biota, and sediment samples and measuring radiation levels during a time when the effects of riverbank spring discharges and groundwater upwelling into the river was likely to be present.

Measurement of Tritium in Gas Phase Soil Moisture and Helium-3 in Soil Gas at the Hanford Townsite and 100 K Area

In 1999, soil gas samples for helium-3 measurements were collected at two locations on the Hanford Site. Eight soil gas sampling points ranging in depth from 1.5 to 9.8 m (4.9 to 32 ft) below ground surface (bgs) in two clusters were installed adjacent to well 699-41-1, south of the Hanford Townsite. Fifteen soil gas sampling points, ranging in depth from 2.1 to 3.2 m (7 to 10.4 ft) bgs, were installed to the north and east of the 100 KE Reactor. Gas phase soil moisture samples were collected using silica gel traps from all eight sampling locations adjacent to well 699-41-1 and eight locations at the 100 K Area. No detectable tritium (<240 pCi/L) was found in the soil moisture samples from either the Hanford Townsite or 100 K Area sampling points. This suggests that tritiated moisture from groundwater is not migrating upward to the sampling points and there are no large vadose zone sources of tritium at either location. Helium-3 analyses of the soil gas samples showed significant enrichments relative to ambient air helium-3 concentrations with a depth dependence consistent with a groundwater source from decay of tritium. Helium-3/helium-4 ratios (normalized to the abundances in ambient air) at the Hanford Townsite ranged from 1.012 at 1.5 m (5 ft) bgs to 2.157 at 9.8 m (32 ft) bgs. Helium-3/helium-4 ratios at the 100 K Area ranged from 0.972 to 1.131. Based on results from the 100 K Area, the authors believe that a major tritium plume does not lie within that study area. The data also suggest there may be a tritium groundwater plume or a source of helium-3 to the southeast of the study area. They recommend that the study be continued by placing additional soil gas sampling points along the perimeter road to the west and to the south of the initial study area.

Isotopic tracking of Hanford 300 area derived uranium in the Columbia River.

Our objectives in this study are to quantify the discharge rate of uranium (U) to the Columbia River from the Hanford Sites 300 Area and to follow that U downriver to constrain its fate. Uranium from the Hanford Site has variable isotopic composition due to nuclear industrial processes carried out at the site. This characteristic makes it possible to use high-precision isotopic measurements of U in environmental samples to identify even trace levels of contaminant U, determine its sources, and estimate discharge rates. Our data on river water samples indicate that as much as 3.2 kg/day can enter the Columbia River from the 300 Area, which is only a small fraction of the total load of dissolved natural background U carried by the Columbia River. This very low level of Hanford-derived U can be discerned, despite dilution to <1% of natural background U, 400 km downstream from the Hanford Site. These results indicate that isotopic methods can allow the amounts of U from the 300 Area of the Hanford Site entering the Columbia River to be measured accurately to ascertain whether they are an environmental concern or insignificant relative to natural uranium background in the Columbia River.

Chromium Toxicity Test for Fall Chinook Salmon (Oncorhynchus tshawytscha) Using Hanford Site Groundwater: Onsite Early Life-Stage Toxicity Evaluation

The objective of this study was to evaluate site-specific effects for early life-stage (eyed eggs to free swimming juveniles) fall chinook salmon that might be exposed to hexavalent chromium from Hanford groundwater sources. Our exposure conditions included hexavalent chromium obtained from Hanford groundwater wells near the Columbia River, Columbia River water as the diluent, and locally adapted populations of fall chinook salmon. This report describes both a 96-hr pretest using rainbow trout eggs and an early life-stage test beginning with chinook salmon eggs.

Survey of radiological contaminants in the near-shore environment at the Hanford Site 100-N Area reactor

Past operations at the Hanford Site 100-N Area reactor resulted in the release of radiological contaminants to the soil column, local groundwater, and ultimately to the near-shore environment of the Columbia River. In September 1997, the Washington State Department of Health (WDOH) and the Hanford Site Surface Environmental Surveillance Project (SESP) initiated a special study of the near-shore vicinity at the Hanford Site`s retired 100-N Area reactor. Environmental samples were collected and analyzed for radiological contaminants ({sup 3}H, {sup 90}Sr, and gamma/ emitters), with both the WDOH and SESP analyzing a portion of the samples. Samples of river water, sediment, riverbank springs, periphyton, milfoil, flying insects, clam shells, and reed canary grass were collected. External exposure rates were also measured for the near-shore environment in the vicinity of the 100-N Area. In addition, samples were collected at background locations above Vernita Bridge.

Monitoring Tissue Concentrations of Chromium and Fish Condition in Juvenile Fall Chinook Salmon from the Hanford Reach of the Columbia River

This study involved the collection of juvenile fall Chinook salmon and Columbia River water samples to assess whether fall Chinook salmon population are exposed to chromium that upwells into the river from contaminated groundwater.