Overview of state approaches to vapor intrusion

A large number of states have issued guidance addressing the vapor intrusion pathway making it difficult to keep up with various policies and requirements. We have compiled and reviewed guidance from 35 states, half of which have issued documents within the last three years. A comparison of policies among states shows reasonable consistency in some areas—for example, 20 of 23 states that provide an exclusion distance for subsurface sources of chlorinated volatile organic compounds (VOCs) use a distance of 100 feet. However, more commonly, the policy decisions vary widely. Among states, indoor air screening concentrations for the same VOC vary by more than 2,000 times and subsurface screening concentrations vary by more than 2,000,000 times. These wide discrepancies suggest a need for communication and consensus building in order to increase consistency in the management of the vapor intrusion pathway. © 2012 Wiley Periodicals, Inc.     

Long-Term Biological Monitoring of an Impaired Stream: Synthesis and Environmental Management Implications

The long-term ecological recovery of an impaired stream in response to an industrial facility’s pollution abatement actions and the implications of the biological monitoring effort to environmental management is the subject of this special issue of Environmental Management. This final article focuses on the synthesis of the biological monitoring program’s components and methods, the efficacy of various biological monitoring techniques to environmental management, and the lessons learned from the program that might be applicable to the design and application of other programs. The focus of the 25-year program has been on East Fork Poplar Creek, an ecologically impaired stream in Oak Ridge, Tennessee with varied and complex stressors from a Department of Energy facility in its headwaters. Major components of the long-term program included testing and monitoring of invertebrate and fish toxicity, bioindicators of fish health, fish contaminant accumulation, and instream communities (including periphyton, benthic macroinvertebrate, and fish). Key parallel components of the program include water chemistry sampling and data management. Multiple lines of evidence suggested positive ecological responses during three major pollution abatement periods. Based on this case study and the related literature, effective environmental management of impaired streams starts with program design that is consistent across space and time, but also adaptable to changing conditions. The biological monitoring approaches used for the program provided a strong basis for assessments of recovery from remedial actions, and the likely causes of impairment. This case study provides a unique application of multidisciplinary and quantitative techniques to address multiple and complex regulatory and programmatic goals, environmental stressors, and remedial actions.     

Ecological Benefits of Riparian Reforestation in Urban Watersheds: Study Design and Preliminary Results

Riparian forest restoration has become a major focus of watershed initiatives to improve degraded stream ecosystems. In urban watersheds, however, the ability of riparian forests to improve stream ecosystems may be diminished due to widespread, upland disturbance. This paper presents the methodology and some preliminary results from the first year of fieldwork on a 3-year project designed to assess the ecological benefits of riparian reforestation in urban watersheds. The study is based on an integrated, multidisciplinary sampling of physical, chemical, and biological attributes at forested and non-forested sections of 12 streams with different amounts of urban developement within their watersheds. Restored sections of three streams are also being monitored over the 3-year duration of the project. Sampling and analysis will continue through December 2000.     

Flipper beat frequency and amplitude changes in diving green turtles, <Emphasis Type="Italic">Chelonia mydas</Emphasis>

Using a turtle-borne camera system, changing flipper beat frequency and amplitude were measured in five diving green turtles (Chelonia mydas Linnaeus 1758) in the Bahía de los Angeles, Mexico (28°58′N, 113°33′W). These observations were made between June and August 2002. Turtles worked hardest (i.e., had the highest flipper beat frequency and amplitude) at the start of descents when positive buoyancy is predicted to oppose their forward motion. During the later part of descents, turtles worked less hard in line with opposing buoyancy forces being reduced. For example, flipper beat frequency declined from about 60–80 beats min⁻¹ at the start of descent to around 25–40 beats min⁻¹ after 30 s of the descent. At the start of ascents the flipper beat frequency was around 30 beats min⁻¹, lower than on descent, and declined as the ascent progressed with often passive gliding for the final few meters to the surface. This pattern of effort during diving appears to apply across a range of marine reptiles, birds and mammals suggesting that graded effort during descent and ascent is an optimum solution to minimising the cost of transport during diving.     

Correcting common misconceptions to inspire conservation action in urban environments

Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the tendency to overlook the conservation value of urban environments stems from misconceptions about the ability of native species to persist within cities and towns and that this, in turn, hinders effective conservation action. However, recent scientific evidence shows that these assumptions do not always hold. Although it is generally true that increasing the size, quality, and connectivity of habitat patches will improve the probability that a species can persist, the inverse is not that small, degraded, or fragmented habitats found in urban environments are worthless. In light of these findings we propose updated messages that guide and inspire researchers, practitioners, and decision makers to undertake conservation action in urban environments: consider small spaces, recognize unconventional habitats, test creative solutions, and use science to minimize the impacts of future urban development.