GeoHEALTH—USGS Newsletter, March 2025
Statewide Assessment of Iowa Streams Links Landscape Characteristics to Antibiotic Resistance Signatures
U.S. Geological Survey (USGS) scientists conducted the first statewide assessment of antibiotics, antibiotic resistant bacteria (ARB), and antibiotic resistant genes (ARGs) in streams (water column and bed sediment samples) across Iowa. Results indicated that ARB and ARGs were prevalent, and a combination of watershed characteristics (such as land use, livestock population, and human population) were related to the antibiotic resistance signatures observed.
Preliminary Research Sheds Light on Proper Analysis and Sample Handling for the Tire-Derived Contaminants 6PPD and 6PPD-quinone
Tire and road wear particles have been shown to cause acute effects to sensitive aquatic animals and degrade their habitats. U.S. Geological Survey (USGS) scientists developed methods to accurately identify aquatic compounds, such as 6PPD and 6PPD-quinone, that can cause acute mortality events in coho salmon (Oncorhynchus kisutch).
A National Predictive Model for PFAS Occurrence in Groundwater
In October of 2024, USGS Scientist’s published a study where they created a model to predict PFAS occurrence in groundwater at the depths of drinking water supplies. This model can help guide our partners to sample areas where PFAS in drinking water could be an issue for the public.
The Environmental Health Program's Source-to-Receptor Strategic Approach
Is a framework used to understand the sources, occurrence, fate and transport of contaminants in the environment, and enables natural resource managers to understand when, where, and how humans and wildlife may be exposed to contaminants.
Increased Mercury, Reduced Insect Diversity, and Food Web impacts from Historical Mercury Mining
U.S. Geological Survey scientists are seeking to understand the impacts of mercury mining on headwater streams, organisms, and food webs, focused on potential effects from historical mining in central Idaho. Mercury associated with mine waste can leave a legacy of contamination that continues to impact stream health in culturally and ecologically important headwater streams after mining activities stop.
Wildfires Increase Mercury Concentrations in Headwater Streams
The U.S. Geological Survey is researching the effect of wildfires on the release of stored mercury from forest watersheds and subsequent transport, methylmercury formation, and bioaccumulation post-fire. Wildfires not only alter the re-release of mercury into the environment but also affect its reactivity and availability to the food web, complicating predictions of mercury exposure risks to wildlife and humans amid other co-occurring stressors.
Innovative Sensor Development for Detecting Low-Micrometer Plastics in Freshwater Systems
Plastic pollution is a significant global issue in aquatic ecosystems, with low-micrometer plastics (LMMPs) posing particular risks owing to their small size and prevalence in various environments. The U.S. Geological Survey and collaborators are developing an innovative sensor to detect and analyze LMMPs in freshwater systems, achieving rapid and accurate results without the need for additional processing.
Wings of Change: The Environment's Influence on Bird Flu
Low pathogenic avian influenza (LPAI) viruses naturally occur in wild birds and are rarely fatal. Highly pathogenic avian influenza (HPAI) viruses are highly contagious, spread rapidly, are often fatal to poultry, and have been responsible for worldwide outbreaks. Together, LPAI and HPAI are generally referred to as either avian influenza viruses (AIVs) or "the bird flu."
Nutrient Management for Harmful Algal Blooms: The Importance of Nitrogen and Micronutrients in the Great Lakes
Managing harmful algal blooms in the Great Lakes requires understanding the roles of nitrogen, phosphorus, and micronutrients, emphasizing a comprehensive approach beyond just phosphorus reduction.
