Steven Fryday - Academia.edu (original) (raw)

Papers by Steven Fryday

Research paper thumbnail of Summary of responses to DEMETRA survey

Quantitative Structure-Activity Relationships (QSAR) for Pesticide Regulatory Purposes, 2007

‘For NTP, usually ED50 for fresh/dry weight or plant height are used as end-points. I have no dat... more ‘For NTP, usually ED50 for fresh/dry weight or plant height are used as end-points. I have no data on hand regarding repeated assays under completely repeatable conditions (e.g. climatic chambers). Under glasshouse conditions ED50-values for plants may vary by up to the factor of 50, but is usually between 5 and 10. For endpoints regarding other organisms, I would have to look up EU monographs, which you probably would have done by now yourself. Colleagues told me however, that the variation is in the same order of magnitude as for NTP’.

Research paper thumbnail of Detection and drivers of exposure and effects of pharmaceuticals in higher vertebrates

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, Jan 19, 2014

Pharmaceuticals are highly bioactive compounds now known to be widespread environmental contamina... more Pharmaceuticals are highly bioactive compounds now known to be widespread environmental contaminants. However, research regarding exposure and possible effects in non-target higher vertebrate wildlife remains scarce. The fate and behaviour of most pharmaceuticals entering our environment via numerous pathways remain poorly characterized, and hence our conception and understanding of the risks posed to wild animals is equally constrained. The recent decimation of Asian vulture populations owing to a pharmaceutical (diclofenac) offers a notable example, because the exposure route (livestock carcasses) and the acute toxicity observed were completely unexpected. This case not only highlights the need for further research, but also the wider requirement for more considered and comprehensive 'ecopharmacovigilance'. We discuss known and potential high risk sources and pathways in terrestrial and freshwater ecosystems where pharmaceutical exposure in higher vertebrate wildlife, prin...

Research paper thumbnail of QSARs for regulatory purposes

Quantitative Structure-Activity Relationships (QSAR) for Pesticide Regulatory Purposes, 2007

The risk to the environment covers the fate and behavior of an active substance (AS), as well as ... more The risk to the environment covers the fate and behavior of an active substance (AS), as well as its possible effects to nontarget organisms. Currently, the initial first tier assessment uses standard toxicity studies. It can also be seen that if concern is raised—a regulatory trigger is breached—higher tier data are requested. These may either address the effects or exposure elements of the risk assessment. In an assessment, there is a consideration of the number of formulation studies conducted and hence submitted. It is not intended that quantitative structure–activity relationships (QSARs) should be able to predict the toxicity of a formulation. The information on formulations was included to indicate the number of studies that may be submitted to address a specific Annex point through the use of toxicity studies. If a QSAR is developed that predicts the toxicity of the AS, then it may be possible to use this information to determine the toxicity of simple formulations. It is not proposed that formulation studies are used in the development of a QSAR, unless it can be clearly demonstrated that the coformulants have not affected the toxicity of the AS. Studies on QSARs for toxicological end points are numerous and tend to give satisfactory results for industrial chemicals, although studies on pesticides give more variable results. A brief overview of how QSARs are used in various regulatory bodies is provided.

Research paper thumbnail of Potential impacts of synergism in honeybees (Apis mellifera) of exposure to neonicotinoids and sprayed fungicides in crops

Apidologie, 2014

Assessment of the toxicity of individual pesticides to honeybees is routinely assessed. However, ... more Assessment of the toxicity of individual pesticides to honeybees is routinely assessed. However, few data have been generated for realistic mixtures of neonicotinoid insecticides and fungicides particularly with regard to exposure levels used. Assessment of the effects of exposure of bees to predicted residues following sprayed applications of ergosterol biosynthesis inhibitor fungicides on the contact and oral toxicity of a range of neonicotinoid insecticides (thiamethoxam, clothianidin, imidacloprid and thiacloprid) showed only low levels of synergism (<3-fold maximum). Further studies showed that the scale of increase in toxicity was fungicide dose dependent with greater synergy of oral toxicity of thiamethoxam following contact dosing with propiconazole. This underlines the need for the use of realistic exposure levels and routes in studies. honeybees / synergism / EBI fungicides / neonicotinoids

Research paper thumbnail of The Effects of Social Learning On the Food Choice of the House Sparrow (Passer Domesticus)

Behaviour, 1994

The effects of social feeding on the selection of novel coloured food and food intake by house sp... more The effects of social feeding on the selection of novel coloured food and food intake by house sparrows (Passer domesticus) were studied in three experiments. In the first experiment, birds were given the choice of feeding on two novel types of coloured food after observations of an experienced bird feeding on them. These observers consumed more food of the colour that they had observed being eaten and also had an elevated total consumption compared to birds that had observed coloured food alone. In the second experiment, birds were given a choice between red and yellow food while adjacent to an experienced bird that was feeding on either red food or quinine-treated red food. The group observing consumption of treated red food consumed less red food than the other group. There was a significant correlation between consumption by the experienced bird and the consumption of red food by the observer which suggested that this effect was not due to a learned aversion. The third experiment was carried out to investigate the effect of previous experience on the behaviour of observers feeding in the presence of demonstrators eating red food or quinine-treated red food. The observers had either 'good' (untreated red food) or 'bad' (quinine-treated red food) experience before observation trials. It was found that only the previous good or bad experience of the observers affected consumption and there was no difference based on the feeding experiences of the demonstrators. These results are discussed in relation to the opportunities for, and types of, social learning of food preferences that may occur in house sparrow flocks.

Research paper thumbnail of Woodpigeon Columba palumbus movements in eastern England: Woodpigeons range over greater areas during winter than summer with winter dispersion greatest in the first two winters following fledging

Bird Study, 2003

Page 1. This article was downloaded by: [66.249.68.105] On: 12 July 2011, At: 01:46 Publisher: Ta... more Page 1. This article was downloaded by: [66.249.68.105] On: 12 July 2011, At: 01:46 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK ...

Research paper thumbnail of Summary of responses to DEMETRA survey

Quantitative Structure-Activity Relationships (QSAR) for Pesticide Regulatory Purposes, 2007

‘For NTP, usually ED50 for fresh/dry weight or plant height are used as end-points. I have no dat... more ‘For NTP, usually ED50 for fresh/dry weight or plant height are used as end-points. I have no data on hand regarding repeated assays under completely repeatable conditions (e.g. climatic chambers). Under glasshouse conditions ED50-values for plants may vary by up to the factor of 50, but is usually between 5 and 10. For endpoints regarding other organisms, I would have to look up EU monographs, which you probably would have done by now yourself. Colleagues told me however, that the variation is in the same order of magnitude as for NTP’.

Research paper thumbnail of Detection and drivers of exposure and effects of pharmaceuticals in higher vertebrates

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, Jan 19, 2014

Pharmaceuticals are highly bioactive compounds now known to be widespread environmental contamina... more Pharmaceuticals are highly bioactive compounds now known to be widespread environmental contaminants. However, research regarding exposure and possible effects in non-target higher vertebrate wildlife remains scarce. The fate and behaviour of most pharmaceuticals entering our environment via numerous pathways remain poorly characterized, and hence our conception and understanding of the risks posed to wild animals is equally constrained. The recent decimation of Asian vulture populations owing to a pharmaceutical (diclofenac) offers a notable example, because the exposure route (livestock carcasses) and the acute toxicity observed were completely unexpected. This case not only highlights the need for further research, but also the wider requirement for more considered and comprehensive 'ecopharmacovigilance'. We discuss known and potential high risk sources and pathways in terrestrial and freshwater ecosystems where pharmaceutical exposure in higher vertebrate wildlife, prin...

Research paper thumbnail of QSARs for regulatory purposes

Quantitative Structure-Activity Relationships (QSAR) for Pesticide Regulatory Purposes, 2007

The risk to the environment covers the fate and behavior of an active substance (AS), as well as ... more The risk to the environment covers the fate and behavior of an active substance (AS), as well as its possible effects to nontarget organisms. Currently, the initial first tier assessment uses standard toxicity studies. It can also be seen that if concern is raised—a regulatory trigger is breached—higher tier data are requested. These may either address the effects or exposure elements of the risk assessment. In an assessment, there is a consideration of the number of formulation studies conducted and hence submitted. It is not intended that quantitative structure–activity relationships (QSARs) should be able to predict the toxicity of a formulation. The information on formulations was included to indicate the number of studies that may be submitted to address a specific Annex point through the use of toxicity studies. If a QSAR is developed that predicts the toxicity of the AS, then it may be possible to use this information to determine the toxicity of simple formulations. It is not proposed that formulation studies are used in the development of a QSAR, unless it can be clearly demonstrated that the coformulants have not affected the toxicity of the AS. Studies on QSARs for toxicological end points are numerous and tend to give satisfactory results for industrial chemicals, although studies on pesticides give more variable results. A brief overview of how QSARs are used in various regulatory bodies is provided.

Research paper thumbnail of Potential impacts of synergism in honeybees (Apis mellifera) of exposure to neonicotinoids and sprayed fungicides in crops

Apidologie, 2014

Assessment of the toxicity of individual pesticides to honeybees is routinely assessed. However, ... more Assessment of the toxicity of individual pesticides to honeybees is routinely assessed. However, few data have been generated for realistic mixtures of neonicotinoid insecticides and fungicides particularly with regard to exposure levels used. Assessment of the effects of exposure of bees to predicted residues following sprayed applications of ergosterol biosynthesis inhibitor fungicides on the contact and oral toxicity of a range of neonicotinoid insecticides (thiamethoxam, clothianidin, imidacloprid and thiacloprid) showed only low levels of synergism (<3-fold maximum). Further studies showed that the scale of increase in toxicity was fungicide dose dependent with greater synergy of oral toxicity of thiamethoxam following contact dosing with propiconazole. This underlines the need for the use of realistic exposure levels and routes in studies. honeybees / synergism / EBI fungicides / neonicotinoids

Research paper thumbnail of The Effects of Social Learning On the Food Choice of the House Sparrow (Passer Domesticus)

Behaviour, 1994

The effects of social feeding on the selection of novel coloured food and food intake by house sp... more The effects of social feeding on the selection of novel coloured food and food intake by house sparrows (Passer domesticus) were studied in three experiments. In the first experiment, birds were given the choice of feeding on two novel types of coloured food after observations of an experienced bird feeding on them. These observers consumed more food of the colour that they had observed being eaten and also had an elevated total consumption compared to birds that had observed coloured food alone. In the second experiment, birds were given a choice between red and yellow food while adjacent to an experienced bird that was feeding on either red food or quinine-treated red food. The group observing consumption of treated red food consumed less red food than the other group. There was a significant correlation between consumption by the experienced bird and the consumption of red food by the observer which suggested that this effect was not due to a learned aversion. The third experiment was carried out to investigate the effect of previous experience on the behaviour of observers feeding in the presence of demonstrators eating red food or quinine-treated red food. The observers had either 'good' (untreated red food) or 'bad' (quinine-treated red food) experience before observation trials. It was found that only the previous good or bad experience of the observers affected consumption and there was no difference based on the feeding experiences of the demonstrators. These results are discussed in relation to the opportunities for, and types of, social learning of food preferences that may occur in house sparrow flocks.

Research paper thumbnail of Woodpigeon Columba palumbus movements in eastern England: Woodpigeons range over greater areas during winter than summer with winter dispersion greatest in the first two winters following fledging

Bird Study, 2003

Page 1. This article was downloaded by: [66.249.68.105] On: 12 July 2011, At: 01:46 Publisher: Ta... more Page 1. This article was downloaded by: [66.249.68.105] On: 12 July 2011, At: 01:46 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK ...