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Portland, OR, United States

Wickwire T.,Exponent, Inc. | Johnson M.S.,U.S. Army | Hope B.K.,11 SW Sixth Avenue | Greenberg M.S.,U.S. Environmental Protection Agency
Integrated Environmental Assessment and Management | Year: 2011

Spatially explicit wildlife exposure models have been developed to integrate chemical concentrations dispersed in space and time, heterogeneous habitats of varying qualities, and foraging behaviors of wildlife to give more realistic wildlife exposure estimates for ecological risk assessments. These models not only improve the realism of wildlife exposure estimates, but also increase the efficiency of remedial planning. However, despite being widely available, these models are rarely used in baseline (definitive) ecological risk assessments. A lack of precedent for their use, misperceptions about models in general and spatial models in particular, non-specific or no enabling regulations, poor communication, and uncertainties regarding inputs are all impediments to greater use of such models. An expert workshop was convened as part of an Environmental Security Technology Certification Program Project to evaluate current applications for spatially explicit models and consider ways such models could bring increased realism to ecological exposure assessments. Specific actions (e.g., greater accessibility and innovation in model design, increased communication with and training opportunities for decision makers and regulators, explicit consideration during assessment planning and problem formulation) were discussed as mechanisms to increase the use of these valuable and innovative modeling tools. The intent of this workshop synopsis is to highlight for the ecological risk assessment community both the value and availability of a wide range of spatial models and to recommend specific actions that may help to increase their acceptance and use by ecological risk assessment practitioners. © 2011 SETAC. Source

Stone D.,Oregon State University | Hope B.K.,11 SW Sixth Avenue
Integrated Environmental Assessment and Management | Year: 2010

Fish advisories are important tools in public health practice and are primarily used to translate fish contaminant levels into consumption recommendations for consumers. Even when a targeted advisory is issued, it may alter broad food consumption patterns among the public, including diminishing intake of fish-based protein and polyunsaturated fatty acids. Such alterations may have both positive (e.g., reduced exposure to contaminants) and negative (e.g., loss of health benefits or cultural traditions associated with consuming fish) consequences. Currently, a fish advisory may be based on the potential for either noncarcinogenic or carcinogenic endpoints. Consumption recommendations based on a cancer outcome are likely to be highly restrictive, potentially diminishing opportunities for the recognized health benefits associated with a fish-rich diet. This possibility causes us to raise 3 arguments against using cancer risk as the basis for fish consumption advisories. First, the benefits of fish consumption are widely recognized. Second, the standard methodology to predict cancer risk is likely to overestimate actual risk, often by orders of magnitude. Third, the public's real and perceived concerns about cancer may result in unintended consequences, such as avoidance of fish altogether. As an alternative to cancer-based advisories, we suggest that future advisories incorporate a multidisciplinary public health framework focused on avoiding noncarcinogenic health outcomes and encouraging the public to consume a balanced diet rich in fish. We also suggest that decision makers need to 1) understand which elements of the advisory process are science and which are implicit or default policy, 2) consciously consider whether these policy elements are appropriate for their particular situation, and 3) if not, be willing to make and defend alternative policy choices. © 2009 SETAC. Source

Hope B.K.,11 SW Sixth Avenue
Human and Ecological Risk Assessment | Year: 2011

In Oregon's Willamette River, methylmercury levels in fish triggered health advisories and the need for a mercury Total Maximum Daily Load (TMDL). A translator was used to relate surface water total mercury (C THg) to dissolved methylmercury concentrations (C DMeHg). The USEPA's Spreadsheet-based Ecological Risk Assessment for the Fate of Mercury (SERAFM) was used to elucidate the annual relationship between mercury loads, C THg, and C DMeHg, to investigate whether C THg is a reasonable predictor for C DMeHg, and to consider how load reductions may be affected by the differing annual trajectories of total and methylmercury concentrations. Modeling and observations suggest that C THg and C DMeHg are not directly proportional, that C THg is an inconsistent predictor of C DMeHg, that a single point estimate translator could easily misjudge their relationship, and that C DMeHg may be more responsive to environmental factors than to load alone. While a translator is convenient for relating C THg and C DMeHg for regulatory purposes, it may not, due to environmental factors unrelated to loading, be the most efficaciousmeans for this purpose. TMDLs relying on a translator are advised to conduct co-located total and methylmercury sampling with sufficient frequency to provide information on the watershed-specific annual relationship between total mercury and methylmercury. © Taylor & Francis Group, LLC. Source

Hope B.K.,11 SW Sixth Avenue | Pillsbury L.,3150 NW 229th Ave. | Boling B.,3150 NW 229th Ave.
Science of the Total Environment | Year: 2012

Oregon's Senate Bill 737, enacted in 2007, required the state's 52 largest municipal wastewater treatment plants (WWTP) and water pollution control facilities (WPCF) to collect effluent samples in 2010 and analyze them for persistent organic pollutants. These facilities are located state-wide and represent a variety of treatment types, service population sizes, geographic areas, and flow conditions. Of the 406 chemicals ultimately analyzed, 114 were detected above the level of quantification (LOQ) in at least one sample. Few persistent pollutants were found possibly because of their diversion from effluent via sorption to sludge (solids phase) or high LOQs for certain chemicals. Several pesticides, as well as benzene and phenol degradation products, all previously unreported in effluent, were detected. Ten polychlorinated biphenyls (PCB) congeners were present at low concentrations in ≤ 10 samples, while polychlorinated naphthalenes and dioxins/furans were not detected at all. Twenty-one polybrominated diphenyl ether (PBDE) congeners were found, nine of which have been reported in Osprey eggs in Oregon and Washington. Methylmercury was present in 65% of samples, with average and maximum concentrations of 0.18 and 1.36. ng/L, respectively. Although they are generally assumed to be innocuous by-products of sewage treatment, additional research is needed on potential impacts to aquatic ecosystems of high loadings of coprostanol and cholesterol. These results suggest that effluent, rather than just receiving waters, should itself be analyzed for a wide range of contaminants in order to understand how upstream sources, conveyed through WWTPs and WPCFs, could be impacting aquatic ecosystems. © 2011 Elsevier B.V. Source

Hope B.K.,11 SW Sixth Avenue
Integrated Environmental Assessment and Management | Year: 2012

In 2011, as part of an update to its state water quality standards (WQS) for protection of human health, the State of Oregon adopted a fish consumption rate of 175 g/day for freshwater and estuarine finfish and shellfish, including anadromous species. WQS for the protection of human health whose derivation is based in part on anadromous fish, create the expectation that implementation of theseWQSwill lead to lower contaminant levels in returning adult fish. Whether this expectation can be met is likely a function of where and when such fish are exposed. Various exposure scenarios have been advanced to explain acquisition of bioaccumulative contaminants by Pacific salmonids. This study examined 16 different scenarios with bioenergetics and toxicokinetic models to identify those where WQS might be effective in reducing polychlorinated biphenyls (PCBs)-a representative bioaccumulative contaminant-in returning adult Fall chinook salmon, a representative salmonid. Model estimates of tissue concentrations and body burdens in juveniles and adults were corroborated with observations reported in the literature. Model results suggest that WQS may effect limited (< approximately 2×) reductions in PCB levels in adults who were resident in a confined marine water body or who transited a highly contaminated estuary as out-migrating juveniles. In all other scenarios examined, WQS would have little effect on PCB levels in returning adults. Although the results of any modeling study must be interpreted with caution and are not necessarily applicable to all salmonid species, they do suggest that the ability of WQS to meet the expectation of reducing contaminant loadings in anadromous species is limited. Integr Environ Assess Manag 2012;8:553-562. © 2012 SETAC. Source

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