William H. Benson

Integrating omic technologies into aquatic ecological risk assessment and environmental monitoring: hurdles, achievements, and future outlook.

Background In this commentary we present the findings from an international consortium on fish toxicogenomics sponsored by the U.K. Natural Environment Research Council (Fish Toxicogenomics—Moving into Regulation and Monitoring, held 21–23 April 2008 at the Pacific Environmental Science Centre, Vancouver, BC, Canada). Objectives The consortium from government agencies, academia, and industry addressed three topics: progress in ecotoxicogenomics, regulatory perspectives on roadblocks for practical implementation of toxicogenomics into risk assessment, and dealing with variability in data sets. Discussion Participants noted that examples of successful application of omic technologies have been identified, but critical studies are needed to relate molecular changes to ecological adverse outcome. Participants made recommendations for the management of technical and biological variation. They also stressed the need for enhanced interdisciplinary training and communication as well as considerable investment into the generation and curation of appropriate reference omic data. Conclusions The participants concluded that, although there are hurdles to pass on the road to regulatory acceptance, omics technologies are already useful for elucidating modes of action of toxicants and can contribute to the risk assessment process as part of a weight-of-evidence approach.

Evaluation of estrogenic activity from a municipal wastewater treatment plant with predominantly domestic input

The purpose of this study was to survey estrogenic releases from two primarily domestic wastewater treatment plants over three seasons (1996-1999). Mature male channel catfish were maintained at two sites within each WWTP and a reference site for 21 days. Estrogenic activity of effluent was assessed by the Yeast Estrogen Screen (YES) assay (in 1999) and the expression of the female egg yolk precursor protein, vitellogenin (Vtg) in caged male channel catfish (1996-1998). Serum Vtg of animals exposed at WWTP-A was induced 220% above reference values in the Fall of 1996 and 480% in Spring of 1997. In animals exposed to effluent of WWTP-B, serum Vtg was elevated 370% in Spring of 1997 and 480% in Fall of 1997 relative to fish held in a reference location. Serum 17-beta-estradiol (E2) levels were also significantly elevated 13 and 16-fold in the Fall 1997 and Summer 1998 in the fish exposed to WWTP-A effluent. A 13.5-fold increase in serum E2 was observed in fish exposed to WWTP-B during Fall 1997. Utilizing an E2 concentration-Vtg response curve generated in the laboratory, effluent from both plants (in 1997 and 1998) had estrogen equivalent values ranging from 23 to 123 ng/l E2 equivalents. These values were comparable with YES values obtained from 1999, which indicated the presence of 21 to 147 ng/l E2 equivalents. E2 was responsible for 3 (fall) to 100% (summer) of the YES activity. Glucuronides of E2 were also observed in the treated effluent. These studies indicate that variable estrogenic activity is present in municipal wastewater resulting from domestic activities and that this activity may be significantly altered by environmental factors.

Accounting for Natural Resources and Environmental Sustainability: Linking Ecosystem Services to Human Well-Being

One of societys greatest challenges is to sustain natural resources while promoting economic growth and quality of life. In the face of this challenge, society must measure the effectiveness of programs established to safeguard the environment. The impetus for demonstrating positive results from government-sponsored research and regulation in the United States comes from Congress (General Accountability Office; GAO) and the Executive Branch (Office of Management and Budget; OMB). The message is: regulatory and research programs must demonstrate outcomes that justify their costs. Although the concept is simple, it is a complex problem to demonstrate that environmental research, policies, and regulations cause measurable changes in environmental quality. Even where changes in environmental quality can be tracked reliably, the connections between government actions and environmental outcomes seldom are direct or straightforward. In this article, we describe emerging efforts (with emphasis on the role of the U.S. Environmental Protection Agency; EPA) to frame and measure environmental outcomes in terms of ecosystem services and values-societally and ecologically meaningful metrics for gauging how well we manage environmental resources. As examples of accounting for outcomes and values, we present a novel, low-cost method for determining relative values of multiple ecosystem services, and describe emerging research on indicators of human well-being.

Relationship between ethinylestradiol‐mediated changes in endocrine function and reproductive impairment in Japanese medaka (Oryzias latipes)

Many biochemical endpoints currently are used to describe endocrine function in fish; however, the sensitivity of these parameters as biomarkers of impaired reproduction or sexual development is not well understood. In the present study, adult Japanese medaka (Oryzias latipes) were assessed for reproductive output and endocrine function, including circulating steroid concentrations, ex vivo steroidogenesis from the gonads, aromatase activity, hepatic estrogen receptor (ER), and plasma vitellogenin (VTG) after exposure to 0, 0.2, 5, 500, and 2,000 ng/L of 17alpha-ethinylestradiol (EE) for 14 d. The EE altered these biochemical responses at various sites along the hypothalamus-pituitary-gonadal axis at concentrations as low as 0.2 ng/L, but it only depressed reproductive function at concentrations of 500 ng/L or greater. Offspring also had reduced ability to hatch at 500 ng/L of EE, but this concentration did not produce any other observed changes in development or sexual phenotype. The reproductive parameters correlated well with VTG, ER, and gonadosomatic index (GSI) in both sexes of adult medaka, which could be indicative of the ER-mediated mode of action for EE. Vitellogenin and ER were elevated at higher concentrations of EE in both sexes, whereas GSI was decreased. Overall, most biochemical endpoints were more sensitive than reproduction or development to exposure, indicating that reproductive function may be relatively protected.

A framework for the use of genomics data at the EPA

The US Environmental Protection Agency is developing a new guidance that outlines best practice in the submission, quality assurance, analysis and management of genomics data for environmental applications.

Influence of parental and developmental cadmium exposure on endocrine and reproductive function in Japanese medaka (Oryzias latipes)

Cadmium (Cd) is a ubiquitous element and an important anthropogenic metal contaminant. A series of assays were modified or developed for Japanese medaka (Oryzias latipes), and used to compare the effects of Cd exposure on indicators of endocrine function in adult animals previously exposed in ovo or as hatchlings. Adults were raised either from eggs produced during a 2 week exposure to 0-10 microg/l Cd or from fry exposed for 2 weeks beginning 2 days after hatching. The reproductive capacity of the resulting adults was determined during a 2 week period during which half of the animals were re-exposed to Cd. Two week Cd exposure did not result in reproductive impairment despite producing some changes in circulating steroid concentration. In addition, 1 microg/l cadmium exposure in ovo elevated male hepatic vitellogenin (VTG) relative to controls. Hence, steroid parameters were a better biomarker of cadmium exposure than changes in VTG. However, reproductive impairment was not correlated to change in VTG or plasma steroids.

Broader perspective on ecosystem sustainability: Consequences for decision making

Although the concept of ecosystem sustainability has a long-term focus, it is often viewed from a static system perspective. Because most ecosystems are dynamic, we explore sustainability assessments from three additional perspectives: resilient systems; systems where tipping points occur; and systems subject to episodic resetting. Whereas foundations of ecosystem resilience originated in ecology, recent discussions have focused on geophysical attributes, and it is recognized that dynamic system components may not return to their former state following perturbations. Tipping points emerge when chronic changes (typically anthropogenic, but sometimes natural) push ecosystems to thresholds that cause collapse of process and function and may become permanent. Ecosystem resetting occurs when episodic natural disasters breach thresholds with little or no warning, resulting in long-term changes to environmental attributes or ecosystem function. An example of sustainability assessment of ecosystem goods and services along the Gulf Coast (USA) demonstrates the need to include both the resilient and dynamic nature of biogeomorphic components. Mountain road development in northwest Yunnan, China, makes rivers and related habitat vulnerable to tipping points. Ecosystems reset by natural disasters are also presented, emphasizing the need to understand the magnitude frequency and interrelationships among major disturbances, as shown by (i) the 2011 Great East Japan Earthquake and resulting tsunami, including how unsustainable urban development exacerbates geodisaster propagation, and (ii) repeated major earthquakes and associated geomorphic and vegetation disturbances in Papua New Guinea. Although all of these ecosystem perturbations and shifts are individually recognized, they are not embraced in contemporary sustainable decision making.

Sustainable Watersheds: Integrating Ecosystem Services and Public Health

Sustainable management of aquatic ecosystems is a worldwide priority; the integrity of these systems depends, in turn, on the integrity of the watersheds (catchments) in which they are embedded. In this article, we present the concepts, background, and scientific foundations for assessing, both nationally and at finer scales, the relationships between ecosystem services, human health, and socioeconomic values in the context of water quality, water quantity, landscapes, the condition of watersheds, and the connectivity of waters, from headwaters to estuaries and the coastal ocean. These assessments will be a foundation for what we have termed “watershed epidemiology,” through which the connections between ecosystems and human health can be explored over broad spatial and temporal scales. Understanding and communicating these relationships should lead to greater awareness of the roles watersheds play in human well-being, and hence to better management and stewardship of water resources. The U.S. Environmental Protection Agency is developing the research, models, and planning tools to support operational national assessments of watershed sustainability, building upon ongoing assessments of aquatic resources in streams, rivers, lakes, wetlands and estuaries.

Genomics: Applications, Challenges, and Opportunities for the U.S. Environmental Protection Agency

ABSTRACT Genomics information has great potential to enhance assessment of risks to human health and the environment. Although understanding genomic responses with respect to adverse ecological and human health outcomes is not, as yet, established, it is important to consider the likely future impacts of genomics technologies on risk assessment and decision-making. Four areas are identified as those likely to be influenced by the generation of genomics information within, and the submission of such information to, the U.S. Environmental Protection Agency (USEPA): risk assessment, prioritization of contaminants and contaminated sites, monitoring, and reporting provisions. For each of these risk assessment and regulatory applications, representative activities are presented to illustrate the application. Three major challenges for the USEPA associated with genomics are also identified in the areas of research, technical development, and capacity. The USEPAs initial activities to address these challenges are discussed. The Agency recognizes it must be prepared to use genomics information, and that many scientific, policy, ethical, and legal concerns will need to be addressed. The USEPA also recognizes it is essential to continue to collaborate with other federal agencies, academia, the regulated community, and other stakeholders in order to benefit from ongoing advances in genomics in the wider scientific and regulatory communities.

Sediment quality in near coastal waters of the Gulf of Mexico: Influence of Hurricane Katrina

The results of the present study represent a synoptic analysis of sediment quality in coastal waters of Lake Pontchartrain and Mississippi Sound two months after the landfall of Hurricane Katrina. Posthurricane conditions were compared to prehurricane (2000-2004) conditions, for sediment quality data. There were no exceedances of effects range median (ERM) sediment quality guideline values for chemical contaminants in any of the sediment samples collected from the Lake Pontchartrain or the Mississippi Sound study areas following the hurricane. Lower threshold effects range low (ERL) values were exceeded for As, Cd, and Ni at several stations in both survey areas, similar to levels of contamination observed prior to the hurricane. The comparison of sediment quality indicators before and after the hurricane suggests considerable stability of these systems with respect to short-term ecological impacts. Although other studies have shown storm-related changes could be detected (e.g., effects on benthic communities associated with shifts in salinity), there were no indications of widespread sediment contamination.