Keith R Solomon

..For other responses, such as immune function, stress endocrinology, parasitism, or population-level effects, there are no indications of effects or there is such a paucity of good data that definitive conclusions cannot be made...

..Concentrations measured after ground application presented a greater risk, but the data were sparse and the assessment is more uncertain...

..This paper offers guidance that can be used to identify candidate POPs that have the potential to cause significant adverse effects in the ecosystem...

..17 and 0.21, respectively). However, inclusion of the type of spray nozzle used and the use of gloves while spraying in the model explained increased predictability and explained 68% of the variation...

..gibba) and submerged (M. sibiricum) species of macrophytes. A hazard quotient assessment of the lowest EC10 value indicated significant risk, exceeding the critical HQ value, but not the lowest EC25 value...

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..were consistently > or = 23.9 mg/L PFOA. A risk assessment for these plant species estimated a negligible probability of toxicity being observed from PFOA exposure at current environmental concentrations...

..Data available: http://www.uoguelph.ca/~hsander/...

..The results indicate that using plasma and liver PFC concentrations as surrogate to whole body burden in a top marine predator overestimates the BMFs and TMFs...

..spicatum or L. gibba. A hazard quotient assessment indicated that tylosin poses little risk to either species of macrophyte, with an HQ value calculated to be nearly three orders of magnitude below 1 (0.002)...

..The EC(10) was a more conservative estimate of toxicity than the statistically derived no observed effect concentration. Current concentrations of MCA are not likely to pose a risk to these aquatic plants in surface waters...

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..The appropriateness of a 28-d exposure for measuring steady-state concentrations in tissue of the invertebrates was confirmed, but further study is required for fish...

..Results from this study show that OH-PCB are important environmental contaminants in dolphins and suggest that PCBs, decades after their ban, may still constitute a threat to wildlife...

..No significant correlations were found between concentrations of PFCAs in liver tissue and previously reported polychlorinated biphenyl (PCB) congeners analyzed in fat samples from the same bears...

..The results of this study provide the first in vivo evidence that rainbow trout are responsive to CYP2B-like induction by PCBs and that this enzyme system can influence PCB concentrations and OH-PCB formation in fish...

..The effects observed occurred at considerably greater concentrations than are currently measured in the environment, indicating minimal risk to aquatic organisms...

..The results of this study demonstrate that laboratory held rainbow trout can biotransform a number of PCB congeners and that bioformation is likely an important source of OH-PCBs in wild salmonids of the Great Lakes...

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..Collectively, these studies show that the NAs in OSPW have the potential to negatively affect reproduction in fathead minnows and that HCO₃⁻ reduces the acute and chronic toxicity of NAs...

..Continuous monitoring with key sentinel species and standardization of analytical methods are recommended...

..These chemicals also were detected in urine (mean sigma PFCs, 26.6 +/- 79 ng/g wet wt), indicating that the urinary system is an important pathway of PFC depuration in dolphins...

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..sibiricum exposed to similar mixtures of pharmaceutical compounds. For M. sibiricum and L. gibba, respective minimum differences of 5 and 1%, were detectable, however, these effect sizes are not considered ecologically significant...

..The results of the present study suggest that consumption of invertebrate food items could provide an additional source of exposure to estrogenic substances in vertebrate predators...

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..The assessment found HAAs to be of low risk to aquatic macrophytes and the results are described in the second manuscript of this series...

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..51 nM) yielded HQs at least two orders of magnitude below 1. Therefore, mixtures of SSRIs do not appear to present a hazard to zooplankton communities at environmentally relevant concentrations...

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..gibba (8PM data). Hazard quotients calculated from the 1% and 5% distribution thresholds indicated potential risk only in certain cases...

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..magna and D. pulicaria were not the most sensitive species and that laboratory tests are not always conservative relative to microcosm experiments. Food scarcity due to phytotoxicity was not the reason for the difference...

..Further research is required to elucidate the toxicokinetics and distribution of OH-PCBs in this cetacean...

..A simple deposition model indicated that dry deposition of TFA and TCA should not be neglected in temperate mid-latitude environments and that precipitation concentrations can be successfully predicted by the Henry's law constant...

..5 +/- 1.1 to 64.3 +/- 0.8. Results indicate that TMFs and food chain length (FCL) are key factors in explaining interlake variability in biomagnification of [Hg] among different lakes...

..SFS is proposed to be a simple and fast method to monitor the release of OSPW into ground and surface waters in the oil sands region...

..Partitioning into other environmental compartments such as this may act as a reservoir from which SSRIs may be re-released into surface waters and indicates the potential susceptibility of benthos...

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..DT50 for products were less than 1.2 days. Formation of 4-epi-anh-tetracyclines, occurred at neutral to weak alkaline conditions...

..However, the modification of EFs from bowhead liver to blubber suggests that this species has the ability to enantioselectively biotransform and accumulate several chiral OC compounds...

..Data for the individual compounds are accessible via...

..TCA in some environments poses a slight risk to phytoplankton and future concentrations of TFA and CDFA are likely to increase due to their recalcitrant nature, warranting continued environmental surveillance of HAAs...

..01%. The use of effect measure distributions holds promise as a new risk assessment technique for aquatic plants. Currently, environmental levels of DCA do not pose a risk to these plants...

..azteca and C. tentans, indicating that adverse effects are not expected, and that environmental exposure to EE2 likely poses a low risk to benthic invertebrates...

..Presently, there appears to be little hazard to these freshwater organisms at reported environmental concentrations...

..These data suggest that TCA/TFA mixtures at environmentally relevant concentrations do not pose a significant risk to these aquatic macrophytes...

..In contrast, our data also indicate that considering the low concentrations currently detected in the environment, ATO and EE(2) pose negligible risks to benthic invertebrates...

..Nonetheless, PHCs are also found in marine mammal tissues from the Southern Hemisphere and in remote regions such as the Arctic, reflecting the global distribution and contamination of PHCs in the marine ecosystem...

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..Perfluorooctanoic acid appears to be relatively nontoxic at environmentally relevant concentrations but may impact biochemical and reproductive endpoints under conditions associated with environmental spills...

..9+/-7.4 mg l(-1)). Although these results support field observations of microbial degradation of low molecular weight NAs decreasing OSPW toxicity, it is not clear why larger NAs, given their greater hydrophobicity, would be less toxic...

..Because t1/2s in this experiment were slower than t1/2s reported in other work, water temperature also may be an important factor in determining the t1/2s of all PCB congeners in fish...

..However, the toxicity values are approximately 1000-fold above those detected in the environment indicating negligible risk to aquatic invertebrates...

..Our data provide the first evidence that PFCA precursors are more toxic than the PFCAs themselves...

..The results confirm the need to consider trophic position and fish size when monitoring temporal trends of Hg, particularly for species with different morphotypes...

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..Wet mass was consistently the most sensitive endpoint above 100 microg/L; conversely, frond number was the most sensitive below 100 microg/L. Pigment endpoints were significantly less sensitive than growth endpoints...

..Monensin concentrations measured in surface waters were 40 times lower than the determined no-observable effect concentration (NOEC) of 50 microg/L and do not likely present a risk to zooplankton...

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..In addition to proper evaluation of the various exposure techniques and conditions, a need exists for more consistent inclusion of quality control procedures during testing...

..These data suggest that TCA does not pose a significant risk to these macrophytes up to 10 mg/l, which typically exceeds environmentally relevant concentrations by several orders of magnitude...

..Using this new risk assessment method, we conclude that MCA does not appear to pose a risk to aquatic macrophytes under field conditions at current environmental concentrations...

..Root-organ cultures provide an effective means to evaluate chemical stressors on arbuscular mycorrhizal fungi and can be used to screen for root-based phytotoxicity...

..It is concluded that plant and animal health are vital to maintaining human health, and that pesticides used in food production are, as with pharmaceuticals, a vital tool used to maintain human health...

..These techniques have not been widely applied for risk assessment of dredged materials, however, with appropriate consideration of bioavailability and spatial and nature of the data these techniques can be applied to soils and sediments...

..The DEAE-cellulose treatment had only a minor effect on the NA concentration, no noticeable effect on the NA fingerprint, and no significant effect on the mixture toxicity towards Vibrio fischeri...

..are still uncertain. (Q)SAR's can be important prioritization tools for subsequent experimental risk assessment of pharmaceuticals in surface waters, due to the prevalent lack of ecotoxicological data...

..25+/-0.13 ng/g ww, 1.7+/-0.89 ng/g lw). In all lake trout samples, 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), a major constituent of the flame-retardant FireMaster BP-6, was the predominant PBB congener...

..Also, changes in the aerosol content of the atmosphere resulting from global climate change may affect ozone photolysis rate coefficients and hence reduce or increase tropospheric ozone concentrations...

..Mass spectral interpretation indicated hydroxylated diterpenoids, sesquiterpenoids, and a lignin-derived stilbene as classes of chemicals associated with steroid depressions...

..Dietary exposure will not result in biomagnification of PFAs in juvenile trout, but extrapolation of these bioaccumulation parameters to larger fish and homeothermic organisms should not be performed...

..Results suggest that enantioselective accumulation of PCB-91, 95, and 149 is influenced by PCB concentrations, age, and/or the modification of an uncharacterized stereoselective process (or processes) during sexual maturity...

..Although the present data do not suggest that ibuprofen, fluoxetine, and ciprofloxacin are individually causing adverse effects in surface-water environments, questions remain about additive responses from mixtures...

..Observed photoproducts of several of the pharmaceuticals remained photoreactive, which led to further degradation in irradiated surface waters...

..Although exposure to agricultural inputs did not affect aromatase activities, effects of atrazine or coapplied pesticides on sex steroid homeostasis cannot be excluded at this point...

..We suggest that some of the approaches developed for pesticide risk assessment can be used for VMPs and offer suggestions for the development of a framework for ecological risk assessment of VMPs...

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..The rank order of susceptibility for the test community was Copepoda > Cladocera > Rotifera, assuming all adverse direct effects...

..gibba. This protocol is based on a modified version of a widely accepted static method...

..05). Additional chronic toxicity testing should also be addressed since these compounds are so persistent and recalcitrant...

..Based on statistical sensitivity, ecological relevance, and toxicological sensitivity, we recommend using plant length and root endpoints as indicators of toxicity under field conditions...

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..Our data do not support the hypothesis that atrazine significantly affects reproductive fitness and development of frogs...