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Hall A.T.,Bayer CropScience | McGaughey B.D.,Compliance Services International | Gagne J.A.,Compliance Services International
ACS Symposium Series | Year: 2012

Risk assessment procedures used by the U.S. Environmental Protection Agency (EPA) for pesticides have been worked out over a period of years and are now well-established and well-known by the regulated community. Similarly, the nature of the database needed to support a standard EPA risk assessment for a pesticide is well-established and well-known. These procedures and data are used to make assessments for endpoints that are deemed relevant to the questions at hand for a particular pesticide. In contrast, no instructional guidelines for evaluating data reliability or relevance for the purpose of endangered species assessments for pesticides are in place. This circumstance has resulted in considerable confusion and uncertainty in the overall consultation process. In this paper, we begin with an overview of some methods used to ensure that high quality data are selected for a risk assessment and we then examine what criteria might be applied to whether data are in fact relevant for a given assessment. Finally, we provide examples of how improperly selected data can strongly influence the conclusions of an assessment, if such data are not of high quality or solid relevance. But we also provide guidance on how to decide which studies beyond guideline studies may (and should) be incorporated into the risk assessment. This paper concludes that no instructional guidelines for evaluating relevancy and reliability are in place, and shows that peer review does not always serve that purpose. Consequently, the risk assessor must use due diligence to consider risk assessment and protection goals in light of data reliability and relevance. Suggestions provided here on how a risk assessor might weigh data for use in a given risk assessment hopefully enhance the assessor's ability to utilize or question data and give it the proper role in the given risk assessment exercise. © 2012 American Chemical Society. Source

McGaughey B.D.,Compliance Services International | Hall A.T.,Bayer CropScience | Racke K.D.,Dow AgroSciences
ACS Symposium Series | Year: 2012

It is clear, from the wealth of information and diverse methods discussed by the contributors of chapters in this book, that good science abounds with respect to endangered species assessment. However, definition of whose scientific approach is the "right one" and how a regulatory process should incorporate that science is only now emerging after more than 30 years of uneven and incomplete policy development. This final chapter explores ways in which the "nexus that perplexes" - the complicated intersection of the Federal Insecticide, Fungicide and Rodenticide Act and the Endangered Species Act - might be best improved within the processes that define the current framework of consultation under the Endangered Species Act. Ideas presented by the chapter authors for this volume relate to many lessons learned and this collective wisdom can be applied to clarify a common vision for what successful consultation may look like in the future. A first step toward practical improvement may be for all parties to step back from differences in perspectives, favored methods, and intensity of scientific scrutiny and ask the simple question, "Just what is it we really need to do to cooperatively develop and successfully advance this vision?" This chapter looks back on the contributions made by all authors and distills that wealth of thought to a platform of recommendations for process improvement. Recommendations are made for three main initiatives: (1) establish trust and a cooperative process between agencies; (2) provide resources, or leverage existing resources, to establish priorities for accomplishing the task at hand; and (3) improve communication with and early involvement of stakeholders. © 2012 American Chemical Society. Source

Maund S.J.,Syngenta | Campbell P.J.,Hill International | Giddings J.M.,Compliance Services International | Hamer M.J.,Hill International | And 4 more authors.
Topics in Current Chemistry | Year: 2012

In this chapter we review the ecotoxicology of the synthetic pyrethroids (SPs). SPs are potent, broad-spectrum insecticides. Their effects on a wide range of nontarget species have been broadly studied, and there is an extensive database available to evaluate their effects. SPs are highly toxic to fish and aquatic invertebrates in the laboratory, but effects in the field are mitigated by rapid dissipation and degradation. Due to their highly lipophilic nature, SPs partition extensively into sediments. Recent studies have shown that toxicity in sediment can be predicted on the basis of equilibrium partitioning, and whilst other factors can influence this, organic carbon content is a key determining variable. At present for SPs, there is no clear evidence for adverse population-relevant effects with an underlying endocrine mode of action. SPs have been studied intensively in aquatic field studies, and their effects under field conditions are mitigated from those measured in the laboratory by their rapid dissipation and degradation. Studies with a range of test systems have shown consistent aquatic field endpoints across a variety of geographies and trophic states. SPs are also highly toxic to bees and other nontarget arthropods in the laboratory. These effects are mitigated in the field through repellency and dissipation of residues, and recovery from any adverse effects tends to be rapid. © 2011 Springer-Verlag Berlin Heidelberg. Source

Hall L.W.,University of Maryland College Park | Mitchell G.,FMC Agricultural Products | Giddings J.,Compliance Services International | Mccoole M.,DuPont Company | And 3 more authors.
Environmental Toxicology and Chemistry | Year: 2015

Hyalella azteca are epibenthic invertebrates that are widely used for toxicity studies. They are reported to be more sensitive to pyrethroid insecticides than most other test species, which has prompted considerable use of this species in toxicity testing of ambient surface waters where the presence of pyrethroids is suspected. However, resident H. azteca have been found in some ambient water bodies reported to contain surface water and/or sediment pyrethroid concentrations that are toxic to laboratory reared H. azteca. This observation suggests differences in the sensitivities of laboratory reared and field populations of H. azteca to pyrethroids. The goal of the present study was to determine the sensitivities of laboratory reared and field populations of H. azteca to the pyrethroids bifenthrin and cypermethrin. Specimens of H. azteca were collected from resident populations at field sites that are subject to varied land-use activities as well as from laboratory populations. These organisms were exposed to bifenthrin- or cypermethrin-spiked water in 96-h water-only toxicity tests. The resulting data demonstrated that: 1) field-collected populations in urban and agricultural settings can be >2 orders of magnitude less sensitive to the pyrethroids than laboratory reared organisms; 2) field-collected organisms varied in their sensitivity (possibly based on land-use activities), with organisms collected from undeveloped sites exhibiting sensitivities similar to laboratory reared organisms; and 3) the sensitivity of field-collected "tolerant" organisms increased in subsequent generations reared under laboratory conditions. Potential mechanisms for these differences are discussed. © 2015 SETAC. Source

Poletika N.N.,Dow AgroSciences | Teply M.,Cramer Fish science | Dominguez L.G.,Cramer Fish science | Cramer S.P.,Cramer Fish science | And 6 more authors.
Integrated Environmental Assessment and Management | Year: 2012

This risk assessment applied a framework for determining probable co-occurrence of juvenile spring Chinook salmon (Oncorhynchus tshawytscha) with agricultural pesticides in the Willamette Basin, Oregon (Teply et al. this issue) to characterize risk to the threatened population. The assessment accounted for spatial and temporal distribution of 6 acetylcholinesteraseinhibiting insecticides in salmonid habitat within the basin and their relative contributions to mixture toxicity estimated from chemical monitoring data. The 6 insecticides were chlorpyrifos, diazinon, malathion, carbaryl, carbofuran, and methomyl. Seasonal distributions of the juvenile salmon prey base across the basin were determined and compared to co-occurrence with the insecticide mixture to determine the probability of prey reduction and reduced production of juvenile fish. Probability of effect on freshwater aquatic invertebrates was based on acute toxicity species sensitivity distributions (normalized to the most potent compound, chlorpyrifos) using a novel approach to apply the toxicological concept of concentration addition to species sensitivity distributions with differing slopes. The chlorpyrifos distribution was then used to determine relative sensitivity among various species tested within the important taxa making up the prey base. A prey base index was devised, incorporating diet composition and prey availability, to evaluate the indirect effects of the insecticide mixture on juvenile salmon production occurring as a result of a reduction in the prey base. Our analysis targeted fish use of backwater and off-channel habitat units, because they generally coincide with agricultural lands in lowlands and represent shallow habitat with limited water exchange. The percentage of agricultural land use within 300mof critical habitat stream reaches was used to scale chemical measurement data from a site with high agricultural land use across the full extent of the basin to provide estimates of chemical exposure in each reach. Seasonal impacts were evaluated from mean monthly concentrations. Stressor impact on 5 key taxa was evaluated at each time step and for each reach, and the outcome was compared to a conservation threshold assigned to the prey base index. Only 13% of juveniles reared in backwater, off-channel habitat within 300m of agricultural land. Percent reduction of carrying capacity as a consequence of reduced prey was estimated to be 5% over the entire brood year. This can be considered lost capacity that is probably compensated elsewhere via increased occupancy (emigration to other habitat units within the reach), which is not accounted for in the model. © 2011 SETAC. Source

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