An Evaluation of Selenium Concentrations in Water, Sediment, Invertebrates, and Fish from the Republican River Basin: 1997–1999

The Republican River Basin of Colorado,Nebraska, and Kansas lies in a valley which contains PierreShale as part of its geological substrata. Selenium is anindigenous constituent in the shale and is readily leached intosurrounding groundwater. The Basin is heavily irrigated throughthe pumping of groundwater, some of which is selenium-contaminated, onto fields in agricultural production. Water,sediment, benthic invertebrates, and/or fish were collected from46 sites in the Basin and were analyzed for selenium to determinethe potential for food-chain bioaccumulation, dietary toxicity,and reproductive effects of selenium in biota. Resultingselenium concentrations were compared to published guidelines orbiological effects thresholds. Water from 38% of the sites (n = 18) contained selenium concentrations exceeding 5 g L^-1, which is reported to be a high hazard for selenium accumulation into the planktonic food chain. An additional 12 sites (26% of the sites) contained selenium in water between 3–5 g L^-1, constituting a moderate hazard. Selenium concentrations in sedimentindicated little to no hazard for selenium accumulation fromsediments into the benthic food chain. Ninety-five percent ofbenthic invertebrates collected exhibited selenium concentrationsexceeding 3 g g^-1, a level reported as potentially lethal to fish and birds that consume them. Seventy-five percent of fish collected in 1997, 90% in 1998, and 64% in 1999 exceeded 4 g g^-1selenium, indicating a high potential for toxicity andreproductive effects. However, examination of weight profilesof various species of collected individual fish suggestedsuccessful recruitment in spite of selenium concentrations thatexceeded published biological effects thresholds for health andreproductive success. This finding suggested that universalapplication of published guidelines for selenium may beinappropriate or at least may need refinement for systems similarto the Republican River Basin. Additional research is needed todetermine the true impact of selenium on fish and wildliferesources in the Basin.     

Global pilot study for persistent organic pollutants (POPs) using PUF disk passive air samplers

Polyurethane foam (PUF) disks were deployed at global background sites, to test logistical issues associated with a global monitoring network for persistent organic pollutants (POPs). alpha-HCH, exhibited relatively high and uniform concentrations (17-150 pg/m3) at temperate and arctic sites with elevated concentrations associated with trans-Pacific inflow. Concentrations were much lower (<5 pg/m3) in Bermuda, Chile and Cape Grim. Concentrations for gamma-HCH, the main component of lindane, were spatially similar to the alpha-HCH pattern but lower in magnitude (typically, <10 pg/m3). Chlordane concentrations (sum of cis-chlordane, trans-chlordane and trans-nonachlor) were also low (<10 pg/m3). Dieldrin concentrations were in the range 2-25 pg/m3 at most sites but elevated in Bermuda. Back trajectories suggest that advection from Africa and the US may contribute. Endosulfan, a popular current-use pesticide, exhibited highest concentrations ranging from tens to hundreds of pg/m3. There was good agreement between duplicate samplers at each site and PUF disk-derived air concentrations agreed with high volume data. Few logistical/analytical problems were encountered in this pilot study.     

Patterns of catch and trophic signatures illustrate diverse management requirements of coastal fisheries in Solomon Islands

Coastal fisheries are a critical component of Pacific island food systems; they power village economies and provide nutritious aquatic foods. Many coastal women and men actively fishing in this region rely on multi-species fisheries, which given their extraordinary diversity are notoriously difficult to both characterize, and to manage. Understanding patterns of fishing, diversity of target species and drivers of these patterns can help define requirements for sustainable management and enhanced livelihoods. Here we use a 12-month data set of 8535 fishing trips undertaken by fishers across Malaita province, Solomon Islands, to create fisheries signatures for 13 communities based on the combination of two metrics; catch per unit effort (CPUE) and catch trophic levels. These signatures are in turn used as a framework for guiding suitable management recommendations in the context of community-based resource management. While a key proximate driver of these patterns was fishing gear (e.g. angling, nets or spearguns), market surveys and qualitative environmental information suggest that community fishing characteristics are coupled to local environmental features more than the market value of specific species they target. Our results demonstrate that even within a single island not all small-scale fisheries are equal, and effective management solutions ultimately depend on catering to the specific environmental characteristics around individual communities.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01690-z.     

Analysis of uncertainty consideration in environmental assessment: an empirical study of Canadian EA practice

Identifying and communicating uncertainty is core to effective environmental assessment (EA). This study evaluates the extent to which uncertainties are considered and addressed in Canadian EA practice. We reviewed the environmental protection plans, follow-up programs, and panel reports (where applicable) of 12 EAs between 1995 and 2012. The types of uncertainties and levels of disclosure varied greatly. When uncertainties were acknowledged, practitioners adopted five different approaches to address them. However, uncertainties were never discussed or addressed in depth. We found a lack of suitable terminology and consistency in how uncertainties are disclosed, reflecting the need for explicit guidance, and we present recommendations for improvement. Canadian Environmental Impact Statements are not as transparent with respect to uncertainties as they should be, and uncertainties in EA need to be better considered and communicated.     

An assessment of indoor air quality in recent Mexican immigrant housing in Commerce City, Colorado

An indoor air quality assessment was conducted on 100 homes of recent Mexican immigrants in Commerce City, Colorado, an urban industrial community north of Denver. Head of households were administered a family health survey, filled out an activity diary, and participated in a home inspection. Carbon monoxide (CO) and carbon dioxide (CO₂) were measured for 24 h inside the main living area and outside of the homes. Harvard Impactors were used to collect 24-h samples of PM_2.5 at the same locations for gravimetric analysis. Dust samples were collected by vacuuming carpeting and flooring at four locations within the home and analyzed by ELISA for seven allergens. Mean indoor and outdoor PM_2.5 levels were 27.2 and 8.5 μg m⁻³, respectively. Indoor PM_2.5 and CO₂ were elevated in homes for which the number of hours with door/window open was zero compared to homes in which the number of hours was high (>15 h). Indoor PM_2.5 levels did not correlate with outdoor levels and tended to increase with number of inhabitants, and results indicate that the source of indoor particles were occupants and their activities, excluding smoking and cooking. Mean indoor CO₂ and CO levels were 1170 and 2.4 ppm, respectively. Carbon monoxide was higher than the 24-h National Ambient Air Quality Standard in 3 of the homes. The predominant allergens were cat (Fel d 1) and mouse (Mus m 1) allergens, found in 20 and 34 homes, respectively.     

Reproductive endocrine disruption in smallmouth bass (Micropterus dolomieu) in the Potomac River basin: spatial and temporal comparisons of biological effects

A high prevalence of intersex or testicular oocytes (TO) in male smallmouth bass within the Potomac River drainage has raised concerns as to the health of the river. Studies were conducted to document biomarker responses both temporally and spatially to better understand the influence of normal physiological cycles, as well as water quality and land-use influences. Smallmouth bass were collected over a 2-year period from three tributaries of the Potomac River: the Shenandoah River, the South Branch Potomac and Conococheague Creek, and an out-of-basin reference site on the Gauley River. The prevalence of TO varied seasonally with the lowest prevalence observed in July, post-spawn. Reproductive maturity and/or lack of spawning the previous spring, as well as land-use practices such as application of manure and pesticides, may influence the seasonal observations. Annual, seasonal, and site differences were also observed in the percentage of males with measurable concentrations of plasma vitellogenin, mean concentration of plasma vitellogenin in females, and plasma concentrations of 17β-estradiol and testosterone in both sexes. Bass collected in the South Branch Potomac (moderate to high prevalence of TO) had less sperm per testes mass with a lower percentage of those sperm being motile when compared to those from the Gauley River (low prevalence of TO). An inverse relationship was noted between TO severity and sperm motility. An association between TO severity and wastewater treatment plant flow, percent of agriculture, total number of animal feeding operations, the number of poultry houses, and animal density within the catchment was observed.     

The Use of Subbottom Profiling in Refining Dredge Cuts for a Large‐Scale Sediment Remediation Project

A number of different techniques were employed to locate the target dredge grade on a large‐scale Canadian sediment remediation project. These techniques included various coring events, Seabed Terminal Impact Newton Gradiometer (STING) testing, and geotechnical borings. Despite these techniques, the data set for interpolation of the dredge grade was widely spaced, and some of the investigations were not specifically intended to be used for defining the dredge grade. In order to reduce the risk of extra expenses from contractor claims resulting from differing sediment conditions, more precise planning was required. Due to the size of the area and the desired accuracy, subbottom profiling was identified as a potential tool to provide high‐density coverage across the site. As with any geophysical tool, ground truth data were required to verify and aid in interpretation. This article describes how subbottom profiling was used to refine the dredge grade for the target layer, the associated challenges related to signal loss in some areas, and how they were overcome. ©2017 Wiley Periodicals, Inc.     

Recommendations on the Use of Satellite Remote-Sensing Data for Urban Air Quality

Abstract

In the last 5 yr, the capabilities of earth-observing satellites and the technological tools to share and use satellite data have advanced sufficiently to consider using satellite imagery in conjunction with ground-based data for urban-scale air quality monitoring. Satellite data can add synoptic and geospatial information to ground-based air quality data and modeling. An assessment of the integrated use of ground-based and satellite data for air quality monitoring, including several short case studies, was conducted. Findings identified current U.S. satellites with potential for air quality applications, with others available internationally and several more to be launched within the next 5 yr; several of these sensors are described in this paper as illustrations. However, use of these data for air quality applications has been hindered by historical lack of collaboration between air quality and satellite scientists, difficulty accessing and understanding new data, limited resources and agency priorities to develop new techniques, ill-defined needs, and poor understanding of the potential and limitations of the data. Specialization in organizations and funding sources has limited the resources for cross-disciplinary projects. To successfully use these new data sets requires increased collaboration between organizations, streamlined access to data, and resources for project implementation.     

Combustion-derived substances in deep basins of Puget Sound: historical inputs from fossil fuel and biomass combustion

Reconstructions of 250 years historical inputs of two distinct types of black carbon (soot/graphitic black carbon (GBC) and char-BC) were conducted on sediment cores from two basins of the Puget Sound, WA. Signatures of polycyclic aromatic hydrocarbons (PAHs) were also used to support the historical reconstructions of BC to this system. Down-core maxima in GBC and combustion-derived PAHs occurred in the 1940s in the cores from the Puget Sound Main Basin, whereas in Hood Canal such peak was observed in the 1970s, showing basin-specific differences in inputs of combustion byproducts. This system showed relatively higher inputs from softwood combustion than the northeastern U.S. The historical variations in char-BC concentrations were consistent with shifts in climate indices, suggesting an influence of climate oscillations on wildfire events. Environmental loading of combustion byproducts thus appears as a complex function of urbanization, fuel usage, combustion technology, environmental policies, and climate conditions.