Papers by Francisco Sanchez-Bayo
Bioremediation of Agricultural Soils
Internal Medicine Review, 2016
Two dose response models have traditionally been used in risk assessment. Most regulatory agencie... more Two dose response models have traditionally been used in risk assessment. Most regulatory agencies assume that there is no safe level of exposure to carcinogens but that a threshold, or “safe” exposure level exists for non-carcinogens. However, recent discoveries have cast serious doubt on the validity of this concept. Dose – response relationships of several neurotoxic non-carcinogens were recently shown to be identical to that of an alkylating carcinogen, and were theoretically explained by irreversible receptor binding with an associated irreversible effect. It is also clear by now that the threshold model for non-carcinogens may seriously underestimate actual risk. Risk assessments can no longer assume thresholds for non-carcinogens as a matter of principle when there is mechanistic evidence of receptor-mediated toxicity. A dose response model for receptor-mediated toxicity needs to be developed, and if the shape of the dose-response curve conveys a linear relationship between receptor occupancy and biological response at lower concentrations, a threshold may not exist. For chemicals with a linear dose-response relationship in low dose regions, risk management should be based on the ALARA principle (“as low as reasonably achievable”).
Ecological Impacts of Toxic Chemicals (Open Access), 2011
Integrated Environmental Assessment and Management, Oct 1, 2011
A comparison of environmental risks of pesticides between tropical and nontropical regions has be... more A comparison of environmental risks of pesticides between tropical and nontropical regions has been performed, using data from the literature and modeling outputs based on the physicochemical properties of the compounds. With a few exceptions, the level of risk of exposure for most pesticides in tropical agriculture is similar to that in other climatic regions of the world. Generally, dissipation of pesticides increases under the warm and wet conditions of the tropics, with most of the dissipation occurring through hydrolysis in water and biological degradation in water and soil. High temperatures in the tropics also foster volatilization rates, whereas high precipitation and poor soils tend to increase losses into runoff and, for certain chemicals, affects their leaching behavior. The environmental risk is determined by a balance of soil types, soil organic carbon, pH, and the rates of degradation in the various environmental compartments.
Journal of Pesticide Science, 2004
Arctic, Antarctic, and Alpine Research, Feb 1, 2013
Francisco Sánchez-Bayo* and Average depth of snow in the mountains of southeastern Australia is d... more Francisco Sánchez-Bayo* and Average depth of snow in the mountains of southeastern Australia is decreasing at a rate Ken Green † of 0.48 cm a 1מ , while the duration of the snowpack has been shortened by 18.5 days *Corresponding author: Department of since 1954 3מ( days per decade). The major factors responsible for these declines are Environmental Sciences, University of an increasing temperature trend of 0.36 ЊC per decade, and a reduction in winter precipita-Technology Sydney, 480 Weeroona Road, tion at the rate of 10.1 mm a 1מ. While the depth of the snowpack is dependent upon Lidcombe, NSW 2141, Australia. [email protected] precipitation trends and minimum temperatures (multiple r 2 ס 0.43), the shortening in †Snowy Mountains Region, National Parks the length of the snow period is best predicted by increasing temperatures and reduced and Wildlife Service, P.O. Box 2228, humidity. The major forcing of the warming trend involves greenhouse gasses, in particular Jindabyne, NSW 2627, Australia atmospheric carbon dioxide and water vapor. However, the decline in winter precipitation seems to be unrelated to the forcing of greenhouse gasses, and is instead statistically associated with the Southern Oscillation Index (r ס 0.38). Inverse correlations were found between depth of snow and solar irradiance, which in turn is inversely correlated with the number of sunspots per cycle. The latter findings suggest that the declining precipitation and snow trends could additionally be associated with a reduction in solar activity during the past five decades.
日本応用動物昆虫学会大会講演要旨, Mar 1, 2005
HAL (Le Centre pour la Communication Scientifique Directe), 2017
In July 2009, a group of entomologists and ornithologists met at Notre-Dame-de-Londres, as a resu... more In July 2009, a group of entomologists and ornithologists met at Notre-Dame-de-Londres, as a result of an international enquiry amongst entomologists on the catastrophic decline of insects all over Europe. On the basis of numerous observations in the field as well as overwhelming circumstantial evidence, they came to the hypothesis that the new generation of pesticides, the persistent, systemic, and neurotoxic neonicotinoids and fipronil, introduced in the early 1990s, is likely to be responsible at least in part for these declines. In response to the Appeal of Notre-Dame-de-Londres, the Task Force on Systemic Pesticides (TFSP), which conducted the Worldwide Integrated Assessment (WIA) of systemic pesticides, was established. In undertaking the WIA over the course of five years, the TFSP has examined over 1,100 scientific peer-reviewed papers published over the last two decades. This book contains the main findings of the WIA, which includes translations into Filipino and Spanish.
Environmental Toxicology and Chemistry, 2009
The influence of various diets on the survival, fecundity, and the polyunsaturated fatty acid (PU... more The influence of various diets on the survival, fecundity, and the polyunsaturated fatty acid (PUFA) composition of the benthic estuarine amphipod Melita plumulosa (Zeidler) in laboratory cultures were determined. Apart from a natural silty sediment, six commercial food supplements were examined: an omega-6 PUFA enriched Spirulina-based dry powder, Sera micron; a shrimpbased pellet food; an omega-3 PUFA enriched algal paste, Rotiselco-ALG; an omega-6 PUFA enriched algal dry powder, AlgaMac-ARA (arachidonic acid); flaxseed meal; and an omega-3 PUFA enriched dry powder, Frippak. We have previously established that M. plumulosa cultures perform poorly and eventually decline if provided with silty sediment alone, but will thrive if supplemented with Sera micron. Conversely, if the amphipods are cultured on a nutrient-depleted sand substrate, Sera micron alone does not constitute an adequate feed. The major difference in the fatty acid composition of M. plumulosa cultured on silty sediment compared to amphipods cultured on a sand substrate and both fed Sera micron was an increase in the ratio of omega-3 to omega-6 PUFAs, indicating that the silty sediment provides additional food sources rich in omega-3 PUFAs. Furthermore, amphipods cultured in sand and fed any of the three algal-based foods or the Frippak powder as the sole food source had poor survival rates, although Sera micron maintained the best survival-this was attributed to it containing high amounts of -carotene and terpenoids. Melita plumulosa fed a mixture of Sera micron in conjunction with the omega-3 PUFA enriched Rotiselco-ALG and cultured on a silty substrate were found to have good fecundity with low variability.
Ecotoxicology and Environmental Safety, Jun 1, 2012
Agricultural landscapes, including paddies, play an important role in maintaining biodiversity, b... more Agricultural landscapes, including paddies, play an important role in maintaining biodiversity, but this biodiversity has been under the threat of toxic agro-chemicals. Our knowledge about how aquatic communities react to, and recover from, pesticides, particularly in relation to their residues, is deficient, despite the importance of such information for realistic environmental impact assessment of pesticides. The cumulative ecological impacts on aquatic paddy communities and their recovery processes after two successive annual applications of two systemic insecticides, imidacloprid and fipronil, were monitored between mid-May and mid-September each year. The abundance of benthic organisms during both years was significantly lower in both insecticide-treated fields than in the controls. Largeimpacts of fipronil on aquatic arthropods were found after the two years. Growth of medaka fish, both adults and their juveniles, was affected by the application of the two insecticides. A Principal Response Curve analysis (PRC) showed the escalation and prolongation of changes in aquatic community composition by the successive annual treatments of each insecticide over two years. Residues of fipronil in soil, which are more persistent than those of imidacloprid, had a high level of impact on aquatic communities over time. For some taxonomic groups, particularly for water surface-dwelling and water-borne arthropods, the second annual treatment had far greater impacts than the initial treatment, indicating that impacts of these insecticides under normal use patterns cannot be accurately assessed during short-term monitoring studies, i.e., lasting less than one year. It is concluded that realistic prediction and assessment of pesticide effects at the community level should also include the long-term ecological risks of their residues whenever these persist in paddies over a year.
Science, Nov 14, 2014
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Biological Conservation, Apr 1, 2019
Biodiversity of insects is threatened worldwide. Here, we present a comprehensive review of 73 hi... more Biodiversity of insects is threatened worldwide. Here, we present a comprehensive review of 73 historical reports of insect declines from across the globe, and systematically assess the underlying drivers. Our work reveals dramatic rates of decline that may lead to the extinction of 40% of the world's insect species over the next few decades. In terrestrial ecosystems, Lepidoptera, Hymenoptera and dung beetles (Coleoptera) appear to be the taxa most affected, whereas four major aquatic taxa (Odonata, Plecoptera, Trichoptera and Ephemeroptera) have already lost a considerable proportion of species. Affected insect groups not only include specialists that occupy particular ecological niches, but also many common and generalist species. Concurrently, the abundance of a small number of species is increasing; these are all adaptable, generalist species that are occupying the vacant niches left by the ones declining. Among aquatic insects, habitat and dietary generalists, and pollutant-tolerant species are replacing the large biodiversity losses experienced in waters within agricultural and urban settings. The main drivers of species declines appear to be in order of importance: i) habitat loss and conversion to intensive agriculture and urbanisation; ii) pollution, mainly that by synthetic pesticides and fertilisers; iii) biological factors, including pathogens and introduced species; and iv) climate change. The latter factor is particularly important in tropical regions, but only affects a minority of species in colder climes and mountain settings of temperate zones. A rethinking of current agricultural practices, in particular a serious reduction in pesticide usage and its substitution with more sustainable, ecologically-based practices, is urgently needed to slow or reverse current trends, allow the recovery of declining insect populations and safeguard the vital ecosystem services they provide. In addition, effective remediation technologies should be applied to clean polluted waters in both agricultural and urban environments.
Environmental Science and Pollution Research, Feb 23, 2021
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Papers by Francisco Sanchez-Bayo