bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cholinesterase inhibition in tree swallows (Tachycineta bicolor) and eastern bluebirds (Sialia sialis) exposed to organophosphorus insecticides in apple orchards in Ontario, Canada
Authors: Burgess Neil M , Hunt Katherine A , Bishop Christine , Weseloh D V (Chip) 
Published: March 2010

Abstract
Apple orchards occupy approximately 12,565 ha of land in Ontario, Canada, and are treated with the greatest number and applications of pesticides among all agricultural crops within the province. The potential for exposure to wildlife from frequent organophosphorus (OP) spray applications is therefore considerable. This study investigated the impact of agricultural spray applications of azinphos-methyl, diazinon, phosalone, and phosmet in apple orchards on the cholinesterase (ChE) activity of wild birds nesting in orchards. These four OP pesticides ranked among the most widely used insecticides used on all fruit crops in Ontario in 1988. Tree swallows (Tachycineta bicolor) and eastern bluebirds (Sialia sialis) were chosen as monitor species because they commonly breed and forage within apple orchards, utilize different feeding strategies, and are readily attracted to nest boxes. Brain and plasma ChE activities were determined for nestling bluebirds and swallows, and plasma ChE was measured in adult swallows for comparison with nestling data. In adult tree swallows, mean plasma ChE levels were significantly inhibited 41% compared to controls 12 h after a second application of azinphos-methyl. Mean plasma ChE activity in another group of adult tree swallows dropped by 21 and 19% following a multiple phosmet application. In nestlings, brain ChE activities obtained postspray often fell below predicted activities calculated from control siblings. This trend was especially apparent in the younger nestlings, less than 6 d old. However, for bluebirds the rates of increase of brain ChE with age in nestlings from treated sites was significantly lower than in nestlings from control sites. Brain ChE activity of two nestlings found dead following a phosalone application gave no indication that insecticide exposure was responsible. No other dead or moribund birds were discovered during the course of the study. Sequential plasma sampling of siblings, before and after OP application, was beneficial in reducing the required number of nests sampled by one half, but plasma ChE was less reliable overall than brain ChE in indicating exposure. Results of depressed ChE levels in tree swallows and eastern bluebirds inhabiting apple orchards are consistent with avian species in other orchard monitoring studies. No indication was found that OP exposure due to agricultural spraying in apple orchards adversely affected the survival of the birds we monitored.
Biomarkers of exposure of brown bullheads (Ameiurus nebulosus) to contaminants in the lower Great Lakes, North America
Authors: Arcand-Hoy Lisa D , Metcalfe Chris D 
Published: March 2010

AbstractBrown bullheads (Ameiurus nebulosus) from three contaminated sites (Detroit River, Hamilton Harbour, and Black River) and two relatively clean reference sites (Old Woman Creek and Bay of Quinte) in the lower Great Lakes were monitored for several biomarkers of exposure to chemical contaminants. Bullheads from the contaminated sites had elevated hepatosomatic indices, increased ethoxyresorufin-O-deethylase (EROD) activity, decreased hepatic retinoid stores, and a greater incidence of hepatic neoplasms. Fluorescent aromatic compounds (FACs) in the bile were also elevated in bullheads from the Black River and Hamilton Harbour in comparison to fish from reference sites. A correlation was found between reduction of hepatic retinoid stores and induction of hepatic EROD activity in bullheads. Principal component analysis of biomarker data demonstrated that biomarker patterns in Detroit River bullheads were different from those of Black River and Hamilton Harbour bullheads. Biomarkers in fish are useful monitoring tools for detecting contamination of the aquatic environment, but interpretation of results is limited by within-and between-site variability in the responses, some of which may be explained by mobility of the fish. In contaminated areas, bile fluorescent aromatic compounds appear to be the best indicator of recent exposure to polynuclear aromatic hydrocarbons, whereas responses to other biochemical biomarkers (e.g., EROD and retinoids) appear to be over a longer time period.
Fluorescent aromatic hydrocarbons in bile as a biomarker of exposure of brown bullheads (Ameiurus nebulosus) to contaminated sediments
Authors: Leadly Todd A , Arcand-Hoy Lisa D , Haffner G Doug , Metcalfe Chris D 
Published: March 2010

AbstractAnalysis of fluorescent aromatic compounds (FACs) in the bile of fish has been widely used as a biomarker of exposure to polynuclear aromatic hydrocarbon (PAH) contamination. However, bile FAC data for feral fish populations are typically highly variable, and in a few cases, elevation of FACs has not been observed in fish from contaminated areas. In this study, the bile FACs and hepatic ethoxyresorufin-O-deethylase activity in brown bullheads (Ameiurus nebulosus) exposed in the laboratory to contaminated sediments from Hamilton Harbour, Ontario, Canada, increased by 173-fold within 72 h of initial exposure and rapidly declined thereafter. In bullheads caged in the contaminated Trenton Channel area of the Detroit River, bile FACs also increased rapidly within 4 d of initial exposure to mean levels &gt;3,000 ng of benzo[a]pyrene equivalents per milliliter of bile. Surprisingly, there was no difference in the mean-levels of bile FACs in fish caged above the sediment versus fish caged in direct contact with the sediment, indicating that water may be the major vector for uptake of PAHs. The lower bile FACs in bullheads caged in other regions of the Detroit River were consistent with the lower concentrations of PAHs in the sediments from these areas. These data indicate that bile FAC levels are a biomarker of recent exposure to aromatic hydrocarbons in sediments. However, FAC data were highly variable even in these studies, in which fish were relatively homogeneous in size, feeding status, and exposure history. Therefore, even higher variability in bile FAC data are expected in biomarker studies as a result of differences in reproductive status, size, diet, and mobility of the fish.
Effect of sediment type, feeding level, and larval density on growth and development of a midge (Chironomus riparius)
Authors: Ristola Tiina , Pellinen Jukka , Ruokolainen Minna , Kostamo Auli , Kukkonen Jussi V K 
Published: March 2010

Abstract
A 10-d growth test and an emergence test were performed with Chironomus riparius Meigen in four unpolluted lake sediments (organic carbon content 0.5–57%) using different feeding levels (Tetramin® at 0.03, 0.06, 0.12, or 0.33 mg/larva/d in the growth test and 0, 0.15, or 0.30 mg/larva/d in the emergence test) to study how sediment type and feeding level affect larval growth. To examine effects of larval density on growth, another growth test was performed using densities of one larva per 24, 12, 4.8, or 2.4 cm2 and a feeding level of Tetramin at 0.12 mg/larva/d. Regardless of sediment type, feeding was necessary in the experiments started with first-instar larvae. The effects of sediment physicochemical characteristics on larval growth and development could not be totally compensated for by food addition. When fed, larvae grew best in sandy sediment with low organic carbon content (0.5%). Acceptable survival was achieved with a very low food dose (0.03 mg/larva/d), but a somewhat higher dose (0.12 mg/larva/d) is recommended. Increment of feeding accelerated larval growth and development. Larval growth was correlated to the food dose per individual and to the density of food particles on the sediment surface.
Priority setting for existing chemicals: European Union risk ranking method
Authors: Hansen Bjorn G , van Haelst Anniek G , van Leeuwen Kees , van der Zandt Peter 
Published: March 2010

Abstract
In order to provide a legal framework within the European Union (EU) for the evaluation of existing chemicals (i.e., substances listed in the European Inventory of Existing Commercial Substances), Council Regulation (EEC) 793/93 was adopted, in which the evaluation of the existing chemicals is carried out by four steps, namely data collection, priority setting, risk assessment, and, if necessary, risk reduction. To fulfill the priority-setting step the EU Risk Ranking Method (EURAM) was developed to produce rankings that are the basis for drawing up lists of substances, used for priority setting, among the so-called high production volume chemicals appearing in the International Uniform Chemical Information database. The EURAM ranks substances on the basis of their potential risk to humans and the environment by using a simple exposure-effect model, containing both human health and environmental effect endpoints as well as exposure parameters. The EURAM fulfills criteria for a good chemical ranking scheme and has been applied and used as a basis for selecting substances for the second and the third list of priority substances as foreseen under Council Regulation (EEC) 793/93.
Consensus sediment quality guidelines for polycyclic aromatic hydrocarbon mixtures
Authors: Swartz Richard C 
Published: March 2010

Abstract
Sediment quality guidelines (SQGs) for polycyclic aromatic hydrocarbons (PAHs) have been derived from a variety of laboratory, field, and theoretical foundations. They include the screening level concentration, effects ranges—low and—median, equilibrium partitioning concentrations, apparent effects threshold, ΣPAH model, and threshold and probable effects levels. The resolution of controversial differences among the PAH SQGs lies in an understanding of the effects of mixtures. Polycyclic aromatic hydrocarbons virtually always occur in field-collected sediment as a complex mixture of covarying compounds. When expressed as a mixture concentration, that is, total PAH (TPAH), the guidelines form three clusters that were intended in their original derivations to represent threshold (TEC = 290 μg/g organic carbon [OC]), median (MEC = 1,800 μg/g OC), and extreme (EEC = 10,000 μg/g OC) effects concentrations. The TEC/MEC/EEC consensus guidelines provide a unifying synthesis of other SQGs, reflect causal rather than correlative effects, account for mixtures, and predict sediment toxicity and benthic community perturbations at sites of PAH contamination. The TEC offers the most useful SQG because PAH mixtures are unlikely to cause adverse effects on benthic ecosystems below the TEC.
Life-cycle framework for assessment of site remediation options: Method and generic survey
Authors: Diamond Mriam L , Page Cynthia A , Campbell Monica , McKenna Stephen , Lall Ronald 
Published: March 2010

Abstract
To address burdens associated with contaminated sites and issuing from remediation activities, a life-cycle framework (LCF) was developed, including an approach based on life-cycle management (LCM) and an adaptation of life-cycle assessment (LCA). Intended for application to a wide range of remediation options, the objective of the LCF is to broaden consideration of potential impacts beyond the contaminated site and over a prolonged time frame. The LCM approach is a qualitative method for investigating remediation activities from a life-cycle perspective. This adaptation of the more rigorous, quantitative LCA method has involved specifying appropriate life-cycle stages, a long-term time horizon, a spatial boundary encompassing the contaminated site and other affected locations, a process boundary containing the contaminated soil, and an impact assessment method that considers site- and process-related metrics. To assess the suitability of LCM as a decision-making tool, six generic site remediation options were investigated: no action, encapsulation, excavation and disposal, vapor extraction, in situ bioremediation, and soil washing. The analysis exemplified tradeoffs between the streamlined LCM, and comprehensive, quantitative LCA approaches, and highlighted potential environmental and human health impacts arising from the six technologies investigated.
Silicone-based polymers as oil spill treatment agents
Authors: Pelletier Éamilien , Siron Robert 
Published: March 2010

Abstract
A new family of oil-treatment agents was prepared by reacting polyoxyethylenic surfactants, alkyl alcohols, or carboxylic acids with alkylchlorosilanes in light hydrocarbon solvents. The treating solutions undergo rapid hydrolysis upon contact with the water surface and the reaction products can encapsulate and solidify oil slicks and other floating hydrocarbons. The removal of the resulting silicone—oil residues from the water surface can be performed by simple netting. Residues can be treated by washing with dichloromethane, leaving inert silicone polymers to be discarded and chemically unaltered hydrocarbons to be recycled. The noteworthy advantages in favor of these new oil-treating agents are the ease of synthesis using readily available chemicals, the very low environmental toxicity of silicones, the efficiency of the agents to solidify oil at a high oil to agent ratio, and the ease of recycling of the oil—silicone residues. Silicone treating agents could find their place in the toolbox of oil spill fighters in response to small accidental and intentional spills occurring frequently in marinas, harbors, along recreational beaches, navigation canals, industrial sites, or along highways. The practical problems to be addressed before any attempt at commercialization of these compounds are the use of highly flammable light hydrocarbons as carrier solvents, the production of corrosive HCl during the hydrolysis process, and the relatively high water content of silicone—oil residues to be recycled.
Fate of a new silicone-based oil-treating agent and its effects on marine microbial communities
Authors: Padrós Jaime , Pelletier Émilien , Siron Robert , Delille Daniel 
Published: March 2010

Abstract
A new silicone-based agent was developed to treat and recover oil slicks and various floating oily residues that are often observed in marinas and harbors. As part of its ecotoxicologic assessment, the fate of the treating agent alone or combined with crude oil, and the effects on natural microbial communities were studied in estuarine mesocosms (3.5 m3) over a 9-week period. The ability of the in situ formed silicone layer to trap an oil slick at the water surface was highlighted by a significative reduction in the volatilization, natural dispersion, and sedimentation of the treated oil. The treatment favored the dissolution of light aromatic hydrocarbons such as methyl-naphthalenes but these compounds were rapidly biodegraded in the water column. The agent alone, as well as the treated or untreated oil, had no effect on the biomass and photosynthetic ability of the phytoplankton community entrapped in the mesocosms. A significant stimulation of oil-degrading bacteria was noted in mesocosms containing treated and untreated oil slicks. On the basis of these results, we conclude that the use of a silicone-based treating agent could be an effective countermeasure to an oil spill, with neither deleterious effects to natural microbial communities nor to long-term biodegradation of the unrecovered oil residues.
Effect of kinetics of complexation by humic acid on toxicity of copper to Ceriodaphnia dubia
Authors: Ma Huizhong , Kim Sang Don , Cha Daniel K , Allen Herbert E 
Published: March 2010

Abstract
The rate of reaction of trace metal ions is an important consideration when studying the chemistry of trace metals in natural waters. The application of speciation models to natural water systems requires knowledge of kinetics if reactions are slow. Most bioassay and toxicity tests conducted in static and flow-through systems have not taken reaction kinetics into account. Therefore, results from these studies may overestimate the toxicity in the receiving waters. In the present study, the kinetics of the interaction of Cu(II) with humic acid (HA) and its influence on the toxicity of copper to Ceriodaphnia dubia were investigated by both chemical kinetic studies using a copper ion selective electrode and bioassay tests using a continuous flow-through bioassay system. A two-ligand site with first-order rate constants model gave a very good description of experimental kinetic data of the change of free Cu2+ concentration. Average k1 was 1.85/h and average k2 was 0.094/h. Bioassay tests indicated that different reaction times of copper with HA solution produced different toxic effects to organisms. We determined the hydrodynamic characteristics of the bioassay chambers to better describe the exposure of the organisms to free Cu2+. The bioassays supported the free ion activity model that the bioavailability and therefore toxicity of copper was directly correlated to the free Cu2+ concentration rather than to the total copper concentration. It was further shown that conventional chemical kinetics can be used to predict the toxicity of copper in these bioassays. This study supports the importance of considering reaction kinetics when studying the chemistry of trace metals in natural waters.
Short-term effects of tri-n-butyl-tin on marine sediment samples using nutrient fluxes as effect indicators
Authors: Dahllöf Ingela , Blanck Hans , Hall Per 
Published: March 2010

Abstract
Tri-n-b utyl-tin (TBT) was shown to affect fluxes of inorganic nutrients from incubated marine sediment samples at extremely low additions of TBTCl, 0.25 femtomol/g (fmol/g) dry sediment (∼80 fg/g). The sediment was incubated under both oxic and anoxic conditions in order to decouple processes in the nitrogen cycle. The fluxes of nitrate and ammonium were affected at an addition of 0.25 fmol TBT/g dry sediment in the oxic incubation. The nitrate flux was stimulated, probably due to stimulation of the autotrophic nitrifiers, causing the negative effect on the ammonium flux. This stimulation is consistent with one suggested mode of action of TBT, i.e., uncoupling of the proton gradient causing free electron flow without ATP production. All fluxes in the anoxic incubations were negatively affected, suggesting a reduced capability for mineralization of organic matter. Nitrate and ammonium fluxes in the anoxic incubations were affected at 2.5 and 8 fmol TBT/g dry sediment, respectively. The fluxes of phosphate and silicate in the anoxic incubation were affected at an addition of 0.25 fmol TBT/g dry sediment. The mode of action of TBT for the heterotrophic microorganisms in the anoxic case is likely to be direct inhibition of ATPase.
Bioaccumulation of 2,4,6-trinitrotoluene and polychlorinated biphenyls through two routes of exposure in a terrestrial amphibian: Is the dermal route significant?
Authors: Johnson Mark S , Franke Laura S , Lee Robyn B , Holladay Steven D 
Published: March 2010

AbstractTiger salamanders (Ambystoma tigrinum) were exposed via soil and/or food (earthworms) to 2,4,6-trinitrotoluene (TNT) and a PCB mixture (Aroclor 1260) at environmentally relevant concentrations. Four exposures were considered: (1) uncontaminated food + uncontaminated soil (control group); (2) contaminated soil + uncontaminated food (dermal group); (3) contaminated food + uncontaminated soil (oral group); and, (4) contaminated soil + contaminated food (dual-exposure group). The chemical exposure was estimated for each group by analysis of both soil and earthworms. Body burdens of TNT and its primary metabolites were highest in the dermal groups while PCB burdens were highest in the oral groups. Concentrations of the primary TNT metabolites evaluated, 2-amino-dinitrotoluene (DNT) and 4-amino-DNT, exceeded that of unmetabolized TNT and accumulated to 116 and 670 ng/g, respectively. These results provide evidence that dermal exposures to nitroaromatics in terrestrial salamanders may make an important contribution to total body burden and thus may be important when considering the health consequences of such exposures. Further, the demonstration of the accumulation of TNT and TNT metabolites in a primitive vertebrate may have food web modeling implications.
Higher fluctuating asymmetry as a measure of susceptibility to pesticides in fishes
Authors: Allenbach Dawn M , Sullivan Karen Brown , Lydy Michael J 
Published: March 2010

Abstract
Two species of fishes common to the Great Plains of North America (the western mosquitofish [Gambusia affinis] and the sand shiner [Notropis ludibundus]) were used to examine the relationship between individual time-to-death (TTD) in 96–h toxicity tests and average fluctuating asymmetry (FA). Previous studies have indicated that FA, the random deviation from bilateral symmetry in metric traits, is increased in organisms that develop in stressful and/or marginal environments. This association has led to the prediction that FA may be useful as a bioindicator. For example, if an individual's FA is negatively related to stress resistance, a population that has comparatively high values of FA may be more susceptible to further stressors. Adult fish used in these experiments were captured from natural populations in Kansas and acclimated to laboratory conditions for 1 month before use in toxicity tests. Each species was separately exposed to two insecticides: parathion, an organophosphate, and lindane, an organochlorine. For each TTD test, 200 individuals were exposed over a 96–h period to an LC70 concentration. Dead individuals were removed every 3 h. Individuals that survived the test were sacrificed for comparison to those that died. Measurements for seven external morphologic characters were obtained for each individual and used to estimate average FA. Three of four statistical tests showed a significant negative regression between TTD and average FA, indicating that individuals with smaller FA survived longer in the test conditions. These results support the use of FA as an indicator of susceptibility to pesticides.
Joint action of pollutant combinations (pesticides and metals) on survival (LC50 values) and acetylcholinesterase activity of Tigriopus brevicornis (Copepoda, Harpacticoida)
Authors: Forget Joëlle , Pavillon Jean-François , Beliaeff Benoǐt , Bocquené Gilles 
Published: March 2010

Abstract
The joint toxicity of nine binary mixtures of a metal (arsenic, copper, or cadmium) and a pesticide (carbofuran, dichlorvos, or malathion) was determined in the marine microcrustacean Tigriopus brevicornis (Müller) (Copepoda) by 96-h LC50 tests and measurement of acetylcholinesterase (AChE) inhibition. Acetylcholinesterase is used in the marine coastal environment as a biomarker to evaluate exposure to neurotoxic pollutants, including organophosphorous (OP) and carbamate (C) insecticides and most metals. A toxic unit (TU) approach was used to test the response addition model for mixtures of chemicals with different action modes. Studies of mixtures showed synergistic lethal effects in all cases (the strongest acute effects being observed in coppermalathion, cadmium-malathion, dichlorvos-malathion, and cadmium-dichlorvos combinations). At the sublethal level, the presence of the three metals tested seemed to enhance the inhibitory effects of certain OP and C insecticides.