8 research outputs found
Ecological Risks from Agricultural Land Treated with Biosolids
Author Institution (Arvai and Basta): School of Environment and Natural Resources, The Ohio State University; Author Institution (Lanno): Department of Entomology, The Ohio State Universit
Effects of 17β-Estradiol Exposure on Gamete Development and Viability in Freshwater Unionids
Evidence of a functional role for vertebrate steroids has been demonstrated in a number of invertebrate species, including molluscs. This knowledge has generated interest into the possibility of invertebrate endocrine disruption due to exposure to both exogenous steroid hormones and xenobiotics which can mimic the action of these compounds. Exposure to the natural vertebrate estrogen, 17β-estradiol (E2), for example, has been shown to induce accelerated gamete development in multiple mollusc species. Little information exists, however, for freshwater mussels, a group of exceptional conservation interest.
Here, Daniel Sovic, Raoman Lanno, Dr. Kody Kuehnl, and G. Thomas Watters report the findings of two field studies on gametogenesis (Elliptio complanata, Pleurobema clava) as they relate to seasonal estrogenicity of extracts from Polar Organic Compound Integrative Samplers (POCIS) as determined using the Yeast Estrogen Screen (YES) assay. In order to investigate effects of E2 exposure on gamete maturation and viability in freshwater mussels, Elliptio insulsa were dosed at one of three exposure levels. Effects on ova and sperm development were determined on biopsies collected 10 days and 6 months post-exposure and biopsy-generated data were compared with histological sections of vicera collected immediately following final biopsy collection. Comparisons of data collected via biopsy and traditional histological techniques provided data to evaluate the potential for utilizing non-lethal biopsy sampling to assess Unionid gametogenesis.https://fuse.franklin.edu/forum-2013/1022/thumbnail.jp
Toxicity in lead salt spiked soils to plants, invertebrates and microbial processes: Unraveling effects of acidification, salt stress and ageing reactions
The fate and effects of toxic trace metals in soil freshly spiked soluble metal salts do not mimic those of metals in the field. This study was set up to test the magnitude of effects of salinity, acidification, and ageing on toxicity of lead (Pb) to plants, invertebrates and soil microbial processes. Three soils were spiked with Pb2+ salts up to a concentration of 8000 mg Pb/kg and were tested either after spiking, after soil leaching followed by pH correction, or after a 5-year outdoor ageing period with free drainage followed by pH correction. Soil solution ionic strength exceeded 150 mmol/L in soils tested directly after spiking and this decreased partially after leaching and returned back to background values after 5-year outdoor equilibration. Chronic toxicity to two plants, two invertebrates, and three microbial endpoints was consistently found in all spiked soils that were not leached. This toxicity significantly decreased or became absent after 5 years of ageing in 19 of the 20 toxicity tests by a factor 8 (median factor; range: 1.4->50), measured by the factor increase of total soil Pb dose required to induce 10% inhibition. The toxicity of Pb in leached soils was intermediate between the other two treatments. The lowest detectable chronic thresholds (EC10) in aged soils ranged 350-5300 mg Pb/kg. Correlation analysis, including data of Pb2+ speciation in soil solution, suggests that reduced ionic strength rather than acidification or true ageing is the main factor explaining the soil treatment effects after spiking. It is suggested that future toxicity studies should test fine PbO powder as a relevant source for Pb in soils to exclude the confounding salt effects.publisher: Elsevier
articletitle: Toxicity in lead salt spiked soils to plants, invertebrates and microbial processes: Unraveling effects of acidification, salt stress and ageing reactions
journaltitle: Science of The Total Environment
articlelink: http://dx.doi.org/10.1016/j.scitotenv.2015.07.067
content_type: article
copyright: Copyright © 2015 Elsevier B.V. All rights reserved.status: publishe
Biological significance of metals partitioned to subcellular fractions within earthworms (Aporrectodea caliginosa).
Metal ions in excess of metabolic requirements are potentially toxic and must be removed from the vicinity of important biological molecules to protect organisms from adverse effects. Correspondingly, metals are sequestrated in various forms, defining the accumulation pattern and the magnitude of steady-state levels reached. To investigate the subcellular fractions over which Ca, Mg, Fe, Cu, Zn, Cd, Pb, Ni, and As are distributed, earthworms (Aporrectodea caliginosa) collected from the field were analyzed by isolating metal-rich granules and tissue fragments from intracellular microsomal and cytosolic fractions (i.e., heat-stable proteins and heat-denatured proteins). The fractions showed metal-specific binding capacity. Cadmium was mainly retrieved from the protein fractions. Copper was equally distributed over the protein fraction and the fraction comprising tissue fragments, cell membranes, and intact cells. Zinc, Ca, Mg, and As were mainly found in this fraction as well. Lead, Fe, and Ni were mainly isolated from the granular fraction. To study accumulation kinetics in the different fractions, three experiments were conducted in which earthworms were exposed to metal-spiked soil and a soil contaminated by anthropogenic inputs and, indigenous earthworms were exposed to field soils. Although kinetics showed variation, linear uptake and steady-state types of accumulation patterns could be understood according to subcellular compartmentalization. For risk assessment purposes, subcellular distribution of metals might allow for a more precise estimate of effects than total body burden. Identification of subcellular partitioning appears useful in determining the biological significance of steady-state levels reached in animals
Toward Sustainable Environmental Quality: Priority Research Questions for North America.
Anticipating, identifying, and prioritizing strategic needs represent essential activities by research organizations. Decided benefits emerge when these pursuits engage globally important environment and health goals, including the United Nations Sustainable Development Goals. To this end, horizon scanning efforts can facilitate identification of specific research needs to address grand challenges. We report and discuss 40 priority research questions following engagement of scientists and engineers in North America. These timely questions identify the importance of stimulating innovation and developing new methods, tools, and concepts in environmental chemistry and toxicology to improve assessment and management of chemical contaminants and other diverse environmental stressors. Grand challenges to achieving sustainable management of the environment are becoming increasingly complex and structured by global megatrends, which collectively challenge existing sustainable environmental quality efforts. Transdisciplinary, systems-based approaches will be required to define and avoid adverse biological effects across temporal and spatial gradients. Similarly, coordinated research activities among organizations within and among countries are necessary to address the priority research needs reported here. Acquiring answers to these 40 research questions will not be trivial, but doing so promises to advance sustainable environmental quality in the 21st century. Environ Toxicol Chem 2019;38:1606-1624. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC