GeoHEALTH–USGS Newsletter, August 2020
The GeoHEALTH–USGS Newsletter—published since 2004—provides information on USGS science activities pertinent to safeguarding the health of fish, wildlife, domesticated animals, livestock, and people from environmental exposures to contaminants and pathogens, featuring research from the Toxic Substances Hydrology and Contaminant Biology Programs.
Mixtures of Algal Toxins Present Prior to and After Formation of Visible Algal Blooms—Science to Inform the Timing of Algal Toxin Exposure
Cyanobacteria with toxin-producing potential, genes indicating an ability for toxin synthesis, or cyanotoxins were present before and after formation of a visible algal bloom in Kabetogama Lake, a popular recreation area in Voyageurs National Park that lies along the border of Minnesota and Canada. The temporal patterns observed in this study indicate that sampling only when there is a visible algal bloom and sampling only for microcystin may miss some low-level toxin occurrence of which effects are not well understood.
Framework for Examining Stream Ecosystem Health in Areas of Shale Gas Development—A Multi-Parameter Watershed-Based Case Study in Pennsylvania
In a case study of 25 headwater streams in Pennsylvania, no statistically significant associations were determined between shale gas development and geochemical tracers of produced waters or measures of microbial and macroinvertebrate community composition. Although the results are specific to the region studied, the integrated biological and geochemical framework provides a tool for examining effects of energy development in other watersheds with differing size, land cover, or best management practices.
Satellite Data Used to Estimate and Rank Cyanobacterial Bloom Magnitude in Florida and Ohio Lakes—Developing Tools to Protect Human and Wildlife Health from Cyanotoxin Exposure
Cyanobacterial bloom magnitude during 2003–11 was quantified and ranked in Florida and Ohio lakes with a newly developed modelling tool that allows for the use of multiple satellite data sources and user-defined thresholds. This tool was designed to identify the magnitude of algal blooms, but one metric alone cannot adequately represent the severity of a bloom of interest in terms of toxicity. The combination of this tool with other measures such as bloom frequency, bloom area, and in-lake toxin concentrations, along with advances in satellite data availability, represents an incremental step toward the development of decision tools used to protect health of wildlife and the public from algal toxin exposures.
Small Mammal Bioaccumulation of Contaminants and Radioactivity near a Mixed Low-level Radioactive and Hazardous Chemical Waste Site—Science to Understand Wildlife Exposure to Environmental Contaminants
Pilot-study results document the presence, concentrations, and distribution of polyfluoroalkyl substances (PFASs), polychlorinated biphenyls (PCBs), and tritium in small mammals, insects, plants, and soils adjacent to a mixed low-level radioactive and hazardous chemical waste site near Beatty, Nevada, and provide a better understanding of potential exposure pathways.
Food Web Changes Dampen Expected Reductions in Lake Trout Mercury Levels in Lake Michigan—Invasive Species Play Major Role
Combined analyses of mercury, nitrogen, and carbon isotopes in archived lake trout (Salvelinus namaycush) tissues and sediment cores in Lake Michigan from 1978 to 2012 indicated that lake trout mercury concentrations mirrored declines in mercury sources prior to the arrival of invasive species that changed mercury transfer through the food and dampened the expected decreases in mercury concentration in fish.
Science to Help Understand Exposure and Toxicological Effects of Environmental Mercury to Representative Birds
Exposure and toxicity of environmental mercury to birds can be enhanced or lessened due to the available sources and forms of mercury and other species dependent factors such as life stage, migratory patterns, foraging and nesting behaviors, transfer of mercury from mothers to eggs, and sex. For example, mercury exposure can lead to sublethal toxicological effects that can influence parental nesting behaviors involved in egg incubation. However, the effects are species-specific and can be non-existent for some birds. These findings show how extensive the range of effects can be for a variety of different species and help to differentiate the actual vs the perceived effects of contaminants on individuals, populations, and entire ecosystems.
Refined Model Provides a Screening Tool to Understand Exposure to Contaminants from Incidental Wastewater Reuse
Refinement of the existing national-scale “de facto reuse incidence in our nation’s consumable supply” (DRINCS) model, complemented by field measurements, provides a screening tool to understand human and wildlife exposure to toxicants and pathogens associated with the incidental reuse of treated wastewater in the Shenandoah River watershed. The model results can be accessed in a companion web-based mapping application.
U.S. Geological Survey Microbiologist Selected as an American Society for Microbiology Distinguished Lecturer
Dale Warren Griffin, a U.S. Geological Survey (USGS) environmental public-health microbiologist, was selected as a Waksman Foundation Distinguished Lecturer for the 2020–22 American Society for Microbiology (ASM) Lecture Series.
Mixtures of Organic and Inorganic Chemicals Characterized in Water from the Taps of Residences in the Greater Chicago Area— Science to Understand Contaminant Exposures in Drinking Water
As a component of ongoing research with a coalition of partners, including the U.S. Geological Survey U.S. Environmental Protection Agency, National Institute of Environmental Health Sciences, Colorado School of Mines, University of Illinois Chicago, and University of South Carolina, water was collected from the taps of 45 Chicago-area residences and analyzed for 540 organic and 35 inorganic chemicals contaminants. In addition, the untreated drinking water source in Lake Michigan and treated water before entry to conveyance infrastructure for the Greater Chicago Area were analyzed for comparison. This pilot study in the Chicago area complements a 2016 reconnaissance study of 12 business and 13 residential tapwaters in 11 States throughout the United States.
Ongoing Research to Characterize the Complexity of Chemical Mixtures in Water Resources—Urban Stormwater
A multiagency reconnaissance study of chemicals in urban stormwater, sampled from pipes or ditches during 50 runoff events at 21 sites in 17 states across the United States, demonstrated that stormwater runoff contains complex mixtures of chemicals including polycyclic aromatic hydrocarbons, pesticides, and pharmaceuticals that are indicative of multiple sources in the watershed.
How are Mercury Sources Determined?
USGS scientists use innovative isotopic identification methods to determine mercury sources in air, water, sediments, and wildlife.
GeoHEALTH–USGS Newsletter Issues Prior to 2020
The GeoHEALTH–USGS Newsletter—published since 2004—provides information on new USGS science activities pertinent to safeguarding the health of fish, wildlife, domesticated animals, livestock, and people from environmental exposures to contaminants and pathogens.