bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review of the validation of models used in Federal Insecticide, Fungicide, and Rodenticide Act Environmental exposure assessments
Authors: Jmones Russell L. , Mangels Gary 
Published: March 2010

Abstract
The first activity of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Environmental Model Validation Task Force, established to increase confidence in the use of environmental models used in regulatory assessments, was to review the literature information on validation of the pesticide root zone model (PRZM) and the groundwater loading effects of agricultural management systems (GLEAMS). This literature information indicates that these models generally predict the same or greater leaching than observed in actual field measurements, suggesting that these models are suitable for use in regulatory assessments. However, additional validation research conducted using the newest versions of the models would help improve confidence in runoff and leaching predictions because significant revisions have been made in models over the years, few of the literature studies focused on runoff losses, the number of studies having quantitative validation results is minimal, and modelers were aware of the field results in most of the literature studies. Areas for special consideration in conducting model validation research include improving the process for selecting input parameters, developing recommendations for performing calibration simulations, devising appropriate procedures for keeping results of field studies from modelers performing simulations to validate model predictions while providing access for calibration simulations, and developing quantitative statistical procedures for comparing model predictions with experimental results.
Distribution of chlorinated hydrocarbons in overlying water, sediment, polychaete, and hornyhead turbot (Pleuronichthys verticalis) in the Coastal ocean, Southern California, USA
Authors: Zeng Eddy Y. , Tran Kim 
Published: March 2010

Abstract
1, 1, 1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its primary metabolites (DDTs) and polychlorinated biphenyls (PCBs) are a major source of concern in the Southern California Bight (SCB), USA. The fate of DDTs and PCBs is a key element in assessing the effects imposed by these potential carcinogens on the marine ecosystem. We found that DDTs and PCBs remained widely distributed in the overlying water, sediment, polychaetes, and liver and muscle tissues of the hornyhead turbot (Pleuronichthys verticalis) collected from three nearshore locations of the SCB with different levels of contamination. Student's t tests indicated that the measured partition coefficients between the nonaqueous phases (sediment, polychaete, and fish) and overlying water at a heavily contaminated location were significantly greater than those predicted by the equilibrium partitioning theory (EPT). Measured partition coefficients between the nonaqueous phases and overlying water for a few DDT components at two other stations (moderate and low contamination) were also generally greater than the EPT predictions. On the other hand, DDTs and PCBs in polychaetes and fish tissues may be taken up from sediments via equilibrium partitioning or from food sources. These findings are suggestive of the possibility that contaminated sediments may have become an important source of contamination.
Responses of songbirds to aerial spraying of the microbial insecticide Bacillus thuringiensis var. kurstaki (Foray 48B®) on Vancouver Island, British Columbia, Canada
Authors: Sopuck Lennart , Ovaska Kristiina , Whittington Bruce 
Published: March 2010

Abstract
Use of bacterial insecticides containing Bacillus thuringiensis var. kurstaki (Btk) is gaining popularity as an environmentally safe control measure against lepidopteran pests, but indirect effects on nontarget organisms through reduced prey base have received little attention. Aerial spraying of Btk (Foray 48B®) over a 12,803-ha area on southeastern Vancouver Island (BC, Canada) in May to June 1999 as part of a gypsy moth (Lymantria dispar) control program provided us with an opportunity to examine the responses of songbirds to spray application. To obtain an estimate of species richness and relative abundance, we conducted standard songbird point-count surveys in Garry oak (Quercus garryana)-dominated habitats in Btk-sprayed and unsprayed areas in April to June 1999 and, one year after spraying, in 2000. These surveys revealed no patterns consistent with adverse effects of spraying on the relative abundance of adult birds or singing males for any of the species, whether examined individually or when combined into foraging guilds. An exception was the spotted towhee (Pipilo maculatus), which in 1999, but not in 2000, occurred at significantly lower numbers in sprayed plots after Btk treatment. Intensive searches of plots in sprayed and unsprayed areas revealed no differences in the numbers of songbird broods between the two areas for any of the species examined.
Asia-Pacific mussel watch: Monitoring of butyltin contamination in coastal waters of Asian developing countries
Authors: Sudaryanto Agus , Takahashi Shin , Monirith In , Ismail Ahmad , Muchtar Muswerry , Zheng Jinshu , Richardson Bruce J. , Subramanian Annamalai , Prudente Maricar , Hue Nguyen Duc , Tanabe Shinsuke 
Published: March 2010

Abstract
Butyltin compounds (BTs) including mono-, di-, and tributyltin and total tin (ΣSn), were determined in green mussels (Perna viridis) from various Asian developing countries, such as Cambodia, China (Hong Kong and southern China), Malaysia, India, Indonesia, the Philippines, and Vietnam, to elucidate the contamination status, distribution, and possible sources and to assess the risks on aquatic organisms and humans. Butyltin compounds were detected in green mussels collected from all the sampling location investigated, suggesting widespread contamination of BTs along the coastal waters of Asian developing countries. Among butyltin derivatives, tributyltin (TBT) was the predominant compound, indicating its ongoing usage and recent exposures in Asian coastal waters. Higher concentrations of BTs were found in mussels collected at locations with intensive maritime activities, implying that the usage of TBT as a biocide in antifouling paints was a major source of BTs. In addition, relatively high concentrations of BTs were observed in mussels from aquaculture areas in Hong Kong and Malaysia, as it has been reported in Thailand. With the recent improvement in economic status in Asia, it is probable that an increase in TBT usage will occur in aquaculture. Although contamination levels were generally low in mussel samples from most of the Asian developing countries, some of those from polluted areas in Hong Kong, India, Malaysia, the Philippines, and Thailand revealed levels comparable to those in developed nations. Furthermore, the concentrations of TBT in some mussels from polluted areas exceeded the threshold for toxic effects on organisms and estimated tolerable average residue levels as seafoods for human consumption. A significant correlation was observed between the concentrations of ΣBTs and ΣSn in mussels, and ΣBTs were made up mostly 100% of ΣSn in mussels taken from locations having intensive maritime/human activities. This suggests that anthropogenic BTs represent the major source of tin accumulation in mussels. To our knowledge, this is a first comprehensive report on butyltin pollution monitoring in developing countries in the Asia-Pacific region.
Endocrine disruptors in sewage treatment plants, receiving river waters, and sediments: Integration of chemical analysis and biological effects on feral carp
Authors: Petrovic Mira , Solé Montserrat , López De Alda María J. , Barceló Damià 
Published: March 2010

Abstract
Occurrence of alkylphenol ethoxylates or their metabolites (alkylphenols and carboxylated derivatives), as well as natural and synthetic steroids in sewage treatment plant (STP) effluents and in their receiving waters, has been related to biological effects, measured as alterations of plasma vitellogenin (VTG) concentration in natural fish populations. Water composites of STP influents, effluents, sludge, river water, sediment, and feral carps (Cyprinus carpio) were analyzed over a seven-month period in two tributaries of the Llobregat River (NE Spain). Solid-phase extraction/liquid chromatography/mass spectrometry (SPE-LC-MS) analysis revealed concentrations of up to 31 μg/L for nonylphenol ethoxylates (NPEOs), 15 μg/L for nonylphenol (NP), and 35 μg/L for nonylphenoxy carboxylate (NPE1C) in river water downstream of STPs. These compounds were also found to accumulate in river sediment with concentrations ranging from 10 to 820 μg/kg of NPEOs and from 22 to 645 μg/kg for NP. Natural and synthetic estrogens and progestogens also occurred in the water and sediments analyzed but in the ng/L and μg/kg range, respectively. Vitellogenin fluctuated among sites and sampling periods, but it was found to be increased in male carp collected downstream of the main STP. A correlation between endocrine-disrupting compounds (EDCs) in water and sediment and plasma VTG concentration in male carp was observed, especially for alkylphenolic compounds in water and sediment samples (r = 0.83–0.84 for n = 24) and for estriol and estrone in water (r =0.78 and 0.94 for n = 9 and 8, respectively).
Genetic and demographic responses of mercury-exposed mosquitofish (Gambusia holbrooki) populations: Temporal stability and reproductive components of fitness
Authors: Tatara Christopher Paul , Mulvey Margaret , Newman Michael C. 
Published: March 2010

AbstractTwo previous mesocosm studies showed changes in glucosephosphate isomerase-2 (Gpi-2) allele frequencies in mosquitofish populations exposed to mercury for 111 d or two years. A previous selection component analysis of single-generation populations exposed for 111 d to 18 μ/L Hg suggested that female sexual selection and fecundity selection could contribute to changes in Gpi-2 allele frequencies. The present multigeneration study was conducted to determine the stability of Gpi-2 allele frequencies over four years of mercury exposure, measure the reproductive fitness of Gpi-2 genotypes inhabiting control and mercury-contaminated mesocosms to determine a mechanism explaining changes in Gpi-2 allele frequencies, investigate differences in the demographic characteristics of mercury-exposed and control populations, and investigate the water quality of the mesocosms to determine if variables other than mercury show concordant patterns among mesocosms. Differences in Gpi-2 allele frequencies between control and mercury-exposed populations were stable over four years (˜ eight generations) of mercury exposure. Mercury-exposed female mosquitofish had a lower probability of being gravid than control females (p = 0.001). Mercury-exposed females also had lower fecundity (total number of eggs and embryos) than control females (p = 0.036). Unlike the results of the more intense mercury exposures in the single generation study, no strong evidence was found that Gpi-2 genotype influenced fecundity or the probability of being gravid in both control and mercury-exposed females. The quantification of fitness components is difficult but has the potential to enhance our understanding of how toxicants alter allele frequencies in exposed populations.
An evaluation of the success of dredging as remediation at a DDT-contaminated site in San Francisco Bay, California, USA
Authors: Weston Donald P. , Jarman Walter M. , Cabana Gilbert , Bacon Corinne E. , Jacobson Lisa A. 
Published: March 2010

Abstract
Lauritzen Canal, a portion of San Francisco Bay near Richmond, California, USA, was heavily contaminated with dichlorodiphenyltrichloroethane (DDT) and dieldrin as a result of releases from a pesticide-formulating firm. In 1996 and 1997, 82,000 m3 of contaminated sediment was removed from the canal by dredging. This study evaluated the success of the dredging based largely on body burdens of DDT and its metabolites (ΣDDT) in resident biota, with some data on sediment- and water-contaminant levels and sediment toxicity testing. Sediment disturbance during dredging introduced a pulse of ΣDDT into the Lauritzen Canal ecosystem, and body burdens of fish and invertebrates increased 2- to 76-fold, depending on the species. Approximately 11/2 years after remediation, 11 of 14 indicators showed contamination comparable with or worse than the contamination that existed prior to dredging. Monitoring of mussels up to four years postdredging suggests some modest improvement, although the ΣDDT body burden of canal mussels remained far above the norm for San Francisco Bay. The elevated ΣDDT body burdens in biota that persisted for years after remediation reflect recent exposure and are not merely a result of slow metabolic elimination of the ΣDDT pulse associated with dredging. Sediment ΣDDT concentrations were low immediately after dredging, but within months, the canal bottom became covered with a veneer of fine sediment as contaminated as that that had been removed. The source of this material has not been conclusively established, but we suspect it came from slumping and erosion from the flanks of the canal beneath docks and around pilings where dredging was not done. In retrospect, either capping in place or more thorough dredging may have been more successful in reducing pesticide exposure of the biota, although there were difficulties associated with both alternatives.
Influence of sorbate planarity on the magnitude of rapidly desorbing fractions of organic compounds in sediment
Authors: van Noort Paul C. M. , Cornelissen Gerard , ten Hulscher Theodora E. M. , Belfoid Angelique 
Published: March 2010

Abstract
Organic compounds in sediments are known to distribute between rapid, slowly, and very slowly desorbing sites. This distribution is relevant to bioavailability and risk assessment of organic compounds in sediment. In this study, the fraction desorbing to Tenaxr̀ in 6 h was measured for a range of organic compounds in sediment differing in their extent of planarity. The aim was to determine the influence of the extent of planarity on the distribution over the rapidly desorbing sites on the one hand and the slowly and very slowly desorbing sites on the other. The magnitude of rapidly desorbing fractions, calculated from the fractions desorbed to Tenax in 6 h, decreased with increasing extent of planarity, expressed as sorbate thickness. For a thickness of less than 5.5 to 6 AÅ, rapidly desorbing fractions are approximately equal to those for fully planar compounds, such as polycyclic aromatic hydrocarbons, which have a thickness of about 3 Å. This is in agreement with previously reported differences in sediment-water distribution coefficients between planar polycyclic aromatic hydrocarbons (PAHs) and nonplanar PCBs. The present findings suggest that simple molecular modeling of the thickness of nonplanar organic compounds enables the estimation of the affinity for rapidly desorbing sites relative to planar compounds.
Pacific steelhead (Oncorhynchus mykiss) exposed to chlorpyrifos: Benchmark concentration estimates for acetylcholinesterase inhibition
Authors: Sandahl Jason F. , Jenkins Jeffrey J. 
Published: March 2010

Abstract
Steelhead trout (Oncorhynchus mykiss) were exposed for 96 h to the organophosphate chlorpyrifos to establish benchmark concentration (BMC) values in the low-effect range of brain acetylcholinesterase (AChE) inhibition. The U.S. Environmental Protection Agency (U.S. EPA) benchmark dose software was used to model the data. Benchmark concentrations were determined for a range of inhibition levels at 5, 10, and 20%, at 1 and 2 control standard deviations (SD), and at an experimental limit-of-detection level of 2.5%. One contributing difficulty in establishing precise inhibition BMCs in the lower effect region is the variability associated with the AChE analytical method. To minimize this variability, the Ellman method was modified specifically for analysis of O. mykiss brain tissue. Laboratory-established BMCs for chlorpyrifos were then compared with the U.S. EPA 96-h water quality criteria and with the concentration levels detected in Northwest surface waters that are home to threatened steelhead trout. The U.S. EPA 96-h water quality criteria of 0.083 μg/L is below the BMC02.5, the limit-of-detection value for this study. The average chlorpyrifos concentration detected during a two-week period in one monitored stream was 0.127 μg/L, which approaches the BMC02.5. The peak chlorpyrifos concentration detected at 0.482 μg/L is near the BMC1SD estimate.
Differential sensitivity of four Lobaria lichens to copper in vitro
Authors: Cabral João Paulo 
Published: March 2010

Abstract
Treatment of Lobaria amplissima, Lobaria pulmonaria, Lobaria scrobiculata, and Lobaria virens with 0 to 500 μM CuSO4 for 0 to 120 min at 25.0°C resulted in a time- and copper-concentration-dependent decrease in the thallus total potassium content and a release of K+ from the thallus, indicating that copper damaged the cytoplasmic membrane of the fungal hyphae. Lobaria pulmonaria was the most sensitive species, L. virens the most resistant to copper treatment. Lobaria amplissima and L. scrobiculata displayed intermediate sensitivity. Treatment with copper also resulted in a time-dependent increase in the thallus copper content. For all four Lobaria species, the thallus potassium content decreased linearly with increasing thallus copper content, suggesting that, as cupric ions bound to the thallus, they reach target sites in the membrane. Acetone extracts contained low concentrations of chlorophyll a, amino acids, polyols, and sugars, but detectable or considerable amounts of lichen substances, i.e., constictic, norstictic, stictic, and usnic acids and scrobiculin. Titration of the extracts with copper and assay of free Cu2+ revealed the presence of copper-binding ligands, most probably corresponding to the lichen substances detected in the extracts. Acetone extracts of L. amplissima and L. virens bound small or very small amounts of Cu2+; binding was monophasic and probably involved scrobiculin. Acetone extracts of L. pulmonaria and L. scrobiculata bound high or intermediate amounts of copper; binding was polyphasic and probably involved the lichen acids detected in the extracts. It was concluded that, in the studied Lobaria species, acetone extracts containing lichen substances could bind, in vitro, considerable amounts of Cu2+, but this binding did not prevent membrane damage in the thallus. Several hypotheses are presented to explain these results.
Prediction of soil sorption coefficients with a conductor-like screening model for real solvents
Authors: Klamt Andreas , Eckert Frank , Diedenhofen Michael 
Published: March 2010

Abstract
Using a general theory for partition coefficients based on a quantum chemically derived conductor-like screening model for real solvents σ-moment descriptors, the logarithmic soil sorption coefficients log KOC of a database of 440 compounds has been successfully correlated, achieving a standard deviation (root-means-squared [RMS]) of 0.62 log-units on the training set and a predictive RMS of 0.72 log-units on a more demanding test set. The quality of this generally applicable predictive approach is almost the same as that of a regression of log KOC with experimental log KOW values, which are the best correlations currently available. The error of this new predictive method is only approximately 43% of the error of a recently published model using a different quantum chemically based approach.
Interclonal variation of heavy metal interactions in Salix viminalis
Authors: Landberg Tommy , Greger Maria 
Published: March 2010

Abstract
In the complex chemistry of soil, interactions between metals can be expected and these affect the uptake of the metals by the plants. The role of the metal–metal interaction may vary between different plants. This study was performed to investigate if variations exist in the interactions between Cd, Cu, and Zn on toxicity and accumulation of these metals in different clones of Salix viminalis. Two studies were performed. First, to study interaction at uptake, 10 clones with high or low accumulation capacity of Cd, Cu, and Zn, respectively, were treated with 0.3 μM Cd, 0.1 μM Cu, and 3 μM Zn (all three metals at the same time or separately). Second, to study the effect of one of the metals on the sensitivity of the plant to the other metals, three clones with high or low sensitivity to each of the three metals were used in a modified Weibull analysis. Examination of the results shows that interclonal variation exists in effects of metal interaction on metal accumulation and sensitivity exists. The uptake experiment showed that accumulation of Cu was decreased by the other metals, but only in clones with high Cu-accumulating properties because of decreased net uptake of Cu. The accumulation of Zn in roots was increased two- to threefold in all clones in the presence of the other metals because of a decreased translocation of Zn to the shoot. The accumulation of Cd was not changed by the presence of the other metals in any of the clones. The second experiment showed that the effect of interactions between the different metals on metal toxicity was present in all clones but appeared most frequently in the clone with high Zn resistance. Synergistic effects between Cu and Zn in the Zn-resistant clone suggested that this clone had evolved an additional site of toxic action that was absent in the other clones.
Reduction of estrogenic activity of municipal wastewater by aerated lagoon treatment facilities
Authors: Bringolf Robert B. , Summerfelt Robert C. 
Published: March 2010

AbstractThe estrogenic activity of municipal wastewater in aerated lagoon treatment facilities was evaluated using plasma concentrations of vitellogenin (Vtg) in male fathead minnows (Pimephales promelas). Caged fathead minnows were exposed for 10 to 12 d in three lagoons that are connected in series at each of 10 municipal wastewater treatment facilities in central Iowa. USA, during October and November 2000. Fathead minnows held in the laboratory served as unexposed controls. Pooled (n = 4–10 fish) plasma Vtg, quantified by enzyme-linked immunosorbent assay (ELISA), was 1,702 ± 670 (mean ± standard error [SE]) μg/ml in the first lagoons (n = 9), 0.94 ± 0.36 μg/ml in the second lagoons (n = 10), and 0.04 ± 0.02 μg/ml in the third lagoons (n = 8). Differences in mean fish plasma Vtg concentration among lagoons were highly significant (p &lt; 0.001). The mean concentration of plasma Vtg in fish in the third lagoons was not significantly different (p = 0.990) from that of the control fish (0.04 ± 0.02 μg/ml). Plasma Vtg concentrations of fish in the first lagoons were inversely correlated with wastewater retention time in the lagoons (p = 0.002, r = −0.877). Water temperatures of the final effluents during the study ranged from 9 to 12°C General treatment efficiency of lagoons has been shown to be dependent on temperature, so the potential exists for decreased removal of estrogenic activity when water temperatures are lower (e.g., winter months) than the present study. In conclusion, wastewater entering aerated lagoon systems was estrogenic to fish, but with serial passage through the lagoons, the estrogenic activity decreased to a level that was not sufficient to induce vitellogenesis in male fathead minnows in a 10- to 12-d exposure.