Geology topics

Kimani L. Kimbrough

Publications and source records attributed to Kimani L. Kimbrough.

4 recordsLinked to original sources

USGS2023

Assessing contaminants of emerging concern in the Great Lakes Ecosystem: A decade of method development and practical application

Assessing the ecological risk of contaminants in the field typically involves consideration of a complex mixture of compounds which may or may not be detected via instrumental analyses. Further, there are insufficient data to predict the potential biological effects of many detected compounds, leading to their being characterized as contaminants of emerging concern (CECs). Over the past several years, advances in chemistry, toxicology, and bioinformatics have resulted in a variety of concepts and tools that can enhance the pragmatic assessment of the ecological risk of CECs. The present Focus article describes a 10+- year multiagency effort supported through the U.S. Great Lakes Restoration Initiative to assess the occurrence and implications of CECs in the North American Great Lakes. State-of-the-science methods and models were used to evaluate more than 700 sites in about approximately 200 tributaries across lakes Ontario, Erie, Huron, Michigan, and Superior, sometimes on multiple occasions. Studies featured measurement of up to 500 different target analytes in different environmental matrices, coupled with evaluation of biological effects in resident species, animals from in situ and laboratory exposures, and in vitro systems. Experimental taxa included birds, fish, and a variety of invertebrates, and measured endpoints ranged from molecular to apical responses. Data were integrated and evaluated using a diversity of curated knowledgebases and models with the goal of producing actionable insights for risk assessors and managers charged with evaluating and mitigating the effects of CECs in the Great Lakes. This overview is based on research and data captured in approximately about 90 peer-reviewed journal articles and reports, including approximately about 30 appearing in a virtual issue comprised of highlighted papers published in Environmental Toxicology and Chemistry or Integrated Environmental Assessment and Management . Environ Toxicol Chem 2023;42:2506–2518. © 2023 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Environmental Toxicology and Chemistry↗

USGS2020

A synthesis of ten years of chemical contaminant monitoring data in National Park Service - Southeast and southwest Alaska networks

With the exception of PAHs and trace metals, which were detected at 100% of the sites, all of the other contaminants were detected at varying frequencies. PBBs, Mirex and Endosulfans were not detected in any of the samples and Chlorpyrifos was only detected in five samples across four sites. Chlordanes were present at 79% of the sites while Butyltins were only detected at 20% of the sites. Overall, the majority of the concentrations can be considered to be at background levels when compared to the long-term NOAA National Status and Trends (NS&T) monitoring data for blue mussels nationwide. The relatively high concentrations of cadmium, copper, and nickel in comparison to the NS&T national groups could be a combination of natural inputs and anthropogenic sources. The natural exposure and weathering of rocks in southern Alaska can contribute to elevated background concentrations of these metals. Sample concentrations, compositions and/or trends for Total DDT, Total Dieldrins and Total HCHs suggest that these contaminants are no longer bioaccumulating at detectable levels. Total Butyltin concentrations were low compared to the NS&T national concentrations, but the presence of tributyltin (TBT) in recent years at Sitka Visitor's Center (SITK) and Skagway Harbor (SKWY) indicates that fresh sources of Butyltin are still entering these environments, probably through vessel traffic at these sites. The PAH profiles and higher concentrations at SITK, SKWY and Nahku Bay East Side (NBES) suggest that these sites are receiving anthropogenic sources of PAH contamination. The results included in this report help to provide a greater understanding of general background contamination in NPS SWAN and SEAN parks, as well as other monitoring sites, including range, trends and variability. Future monitoring should aim to continue analyzing the temporal trends of these contaminants on a regional scale through periodic sampling as well as focusing on areas of interest that could shed further insight on range and variation (see supplemental material).

Alaska↗

USGS2014

The Mussel Watch California pilot study on contaminants of emerging concern (CECs): synthesis and next steps

A multiagency pilot study on mussels ( Mytilus spp.) collected at 68 stations in California revealed that 98% of targeted contaminants of emerging concern (CECs) were infrequently detectable at concentrations ⩽1 ng/g. Selected chemicals found in commercial and consumer products were more frequently detected at mean concentrations up to 470 ng/g dry wt. The number of CECs detected and their concentrations were greatest for stations categorized as urban or influenced by storm water discharge. Exposure to a broader suite of CECs was also characterized by passive sampling devices (PSDs), with estimated water concentrations of hydrophobic compounds correlated with Mytilus concentrations. The results underscore the need for focused CEC monitoring in coastal ecosystems and suggest that PSDs are complementary to bivalves in assessing water quality. Moreover, the partnership established among participating agencies led to increased spatial coverage, an expanded list of analytes and a more efficient use of available resources.

California↗

USGS2014

Refocusing Mussel Watch on contaminants of emerging concern (CECs): the California pilot study (2009-10)

To expand the utility of the Mussel Watch Program, local, regional and state agencies in California partnered with NOAA to design a pilot study that targeted contaminants of emerging concern (CECs). Native mussels ( Mytilus spp.) from 68 stations, stratified by land use and discharge scenario, were collected in 2009–10 and analyzed for 167 individual pharmaceuticals, industrial and commercial chemicals and current use pesticides. Passive sampling devices (PSDs) and caged Mytilus were co-deployed to expand the list of CECs, and to assess the ability of PSDs to mimic bioaccumulation by Mytilus . A performance-based quality assurance/quality control (QA/QC) approach was developed to ensure a high degree of data quality, consistency and comparability. Data management and analysis were streamlined and standardized using automated software tools. This pioneering study will help shape future monitoring efforts in California’s coastal ecosystems, while serving as a model for monitoring CECs within the region and across the nation.

California↗