82 research outputs found
Ecological traits interact with landscape context to determine bees' pesticide risk
Widespread contamination of ecosystems with pesticides threatens non-target organisms. However, the extent to which life-history traits affect pesticide exposure and resulting risk in different landscape contexts remains poorly understood. We address this for bees across an agricultural land-use gradient based on pesticide assays of pollen and nectar collected by Apis mellifera, Bombus terrestris and Osmia bicornis, representing extensive, intermediate and limited foraging traits. We found that extensive foragers (A. mellifera) experienced the highest pesticide risk-additive toxicity-weighted concentrations. However, only intermediate (B. terrestris) and limited foragers (O. bicornis) responded to landscape context-experiencing lower pesticide risk with less agricultural land. Pesticide risk correlated among bee species and between food sources and was greatest in A. mellifera-collected pollen-useful information for future postapproval pesticide monitoring. We provide foraging trait- and landscape-dependent information on the occurrence, concentration and identity of pesticides that bees encounter to estimate pesticide risk, which is necessary for more realistic risk assessment and essential information for tracking policy goals to reduce pesticide risk.Analysing pesticide residues in pollen and nectar collected by three bee species along a land-use gradient, the authors show that extensive foragers like Apis mellifera have higher pesticide risk than species that forage at intermediate or limited ranges, irrespective of landscape context
Diffraction and refraction calculations for waves incident on an island
An island of circular cylindrical shape, situated on a paraboloidal shoal (Fig. 1 and Table 1) in an infinite ocean of constant depth is attacked by small regular waves of long period and of plane incidence. The wave field around the island is calculated according to two different approaches, viz. a diffraction theory and a refraction theory (i.e. geometrical optics). The solutions are compared for those (tsunami) periods, where the Coriolis force can be neglected
Landscapes of risk: A comparative analysis of landscape metrics for the ecotoxicological assessment of pesticide risk to bees
Pesticide use in agricultural landscapes creates environmental contamination that is heterogenous in space and time. Mobile organisms, such as bees, are exposed to multiple contamination sources when visiting patches that vary in the amount, timing and toxicity of pesticides used. Yet, environmental risk assessments (ERA) typically fail to consider this heterogeneity, in part because of the complexities of estimating exposure to different pesticides, and subsequent risk at organism-relevant scales. We use pesticide assays of 269 bee-collected pollen samples to understand the spatiotemporal variability of risk across a network of 41 field sites in southern Sweden. Observed bee pesticide risk is calculated based on compound-specific residue quantifications in pollen and standardized toxicity data. We then compare the ability of three classes of landscape-scale variables to predict this risk: (1) landscape composition and configuration metrics, (2) landscape load based on national pesticide use data and (3) predictions from a newly developed bee pesticide exposure model. Based on use data, 10 crops account for 81% of the total risk. We detected 49 pesticide compounds in bee-collected pollen. Although herbicides and fungicides constitute the bulk of detected pesticides, both in frequency and amount quantified, unsurprisingly, insecticides contribute the most to risk. Landscape composition and configuration metrics did not predict observed pesticide risk, and interactions with bee species indicate taxa-dependency in predictions. Landscape load predicted observed risk consistently between taxa. Risk estimates from our exposure model were strongly predictive but only when considering realized risk (i.e., risk estimates based on prior pesticide use information). Synthesis and applications. Predicting pesticide risk based on landscape patterns could enable landscape-scale ERA. However, simple metrics of landscape pattern, such as proportion of agricultural land, are not sufficient. We found that risk observed in bee-collected pollen was best predicted when integrating spatialized pesticide use in the pesticide exposure model, underscoring the importance of such data for research, monitoring and mitigation. Further, we propose a guidance framework for future landscape ecotoxicological risk analyses that clarifies data needs relative to risk prediction goals.Predicting pesticide risk based on landscape patterns could enable landscape-scale ERA. However, simple metrics of landscape pattern, such as proportion of agricultural land, are not sufficient. We found that risk observed in bee-collected pollen was best predicted when integrating spatialized pesticide use in the pesticide exposure model, underscoring the importance of such data for research, monitoring and mitigation. Further, we propose a guidance framework for future landscape ecotoxicological risk analyses that clarifies data needs relative to risk prediction goals.imag
Studie av vÀxtskyddsmedels stabilitet i honungsbin samt av individvariation i fÀltexponering
Scientific note: Imidacloprid found in wild plants downstream permanent greenhouses in Sweden
Maturation of monocyte derived dendritic cells with OK432 boosts IL-12p70 secretion and conveys strong T-cell responses
Background: Design of tumour specific immunotherapies using the patientsâ own dendritic cells (DC) is a fast advancing scientific field. The functional qualities of the DC generated in vitro are critical, and todayâs gold standard for maturation is a cytokine cocktail consisting of IL-1b, IL-6, TNF-a and PGE2 generating cells lacking IL- 12p70 production. OK432 is an immunotherapeutic agent derived from killed Streptococcus pyogenes that has been used clinically to treat malignant and benign neoplasms for decades. Methods: In this study, we analysed the effects of OK432 on DC maturation, DC migration, cytokine and chemokine secretion as well as T-cell stimulatory capacity, and compared it to the cytokine cocktail alone and combinations of OK432 with the cytokine cocktail. Results: OK432 induced a marked up-regulation of CD40 on the cell surface as well as a strong inflammatory response from the DC with significantly more secretion of 19 different cytokines and chemokines compared to the cytokine cocktail. Interestingly, secretion of IL-15 and IL-12p70 was detected at high concentrations after maturation of DC with OK432. However, the OK432 treated DC did not migrate as well as DC treated with cytokine cocktail in a transwell migration assay. During allogeneic T-cell stimulation OK432 treated DC induced proliferation of over 50 percent of CD4 and 30 percent of CD8 T-cells for more than two cell divisions, whereas cytokine cocktail treated DC induced proliferation of 12 and 11 percent of CD4 and CD8 T-cells, respectively. Conclusions: The clinically approved compound OK432 has interesting properties that warrants its use in DC immunotherapy and should be considered as a potential immunomodulating agent in cancer immunotherapy
Greenhouse production contributes to pesticide occurrences in Swedish streams
Greenhouse and other covered cultivation systems have increased globally over the past several decades, leading to considerably improved product quality and productivity per land area unit. However, there is a paucity in information regarding the environmental impacts of covered production systems, especially regarding pesticides entering the surrounding environment. Aiming to address this knowledge gap, we collected grab samples downstream of greenhouses from seven Swedish streams every 14 days during a 12 month period. In three of the streams, samples were also taken upstream of the greenhouses and in four of the streams time-integrated samples were collected by TIMFIE samplers in the period between grab sampling occasions. The samples were analyzed for 28 substances (27 that were permitted for use in greenhouse production systems in Sweden and one degradation product to a permitted substance). Pesticide use journals were collected from the greenhouse producers for the 12 month period. The results were examined for indications of greenhouse contributions to detection frequencies, maximum and average concentrations, and potential ecotoxicicity in several ways: (1) comparing locations downstream of greenhouses with registered use of a substance with those without registered use, (2) comparing results from this study with those from the Swedish environmental monitoring program of pesticides in surface water from catchments with no greenhouses from the same period and region, (3) comparing concentration trends with registered pesticide application times in the greenhouses, and (4) comparing up-and downstream concentrations. The results strongly suggest that greenhouse applications do contribute to pesticide occurrences, maximum and median concentrations for most of the pesticides included in this study, and to potential toxicity to aquatic organisms for several of them, most notably imidacloprid, acetamiprid, carbendazim, and pirimicarb
Identifiering av metaboliter frÄn vÀxtskyddsmedel relevanta att analysera i svenska yt- och grundvatten
Vid analyser inom den nationella miljöövervakningen av vĂ€xtskyddsmedel (NMĂ) och annan miljöövervakning ingĂ„r vissa metaboliter frĂ„n vĂ€xtskyddsmedel. Kunskapen om vilka andra metaboliter som kan finnas i grund- och ytvatten i Sverige och som skulle kunna ha negativ effekt pĂ„ miljön eller mĂ€nniskors hĂ€lsa Ă€r bristfĂ€llig.Detta projekt syftar till att identifiera vilka metaboliter frĂ„n vĂ€xtskyddsmedel som kan vara relevanta att analysera i svenska yt- och grundvatten. En bedömning görs ocksĂ„ av vilka som Ă€r praktiskt möjliga att inkludera i analyspaket för den nationella miljöövervakningen.Totalt 33 prover frĂ„n Sverige analyserades för 67 metaboliter av laboratoriet DVGW Technology Centre for Water (TZW) i Karlsruhe, Tyskland. Totalt 22 metaboliter detekterades, 7 i grundvatten och 22 i ytvatten. Elva substanser förekom i halter över 0,1 ”g/l i ytvatten och fyra av dessa över 0,1 ”g/l Ă€ven i grundvatten.Ăvriga underlag som anvĂ€ndes för att identifiera relevanta metaboliter Ă€r: âą Resultat frĂ„n tidigare analyser av metaboliter i Sverige och Danmark âą Underlag om relevans baserat pĂ„ data frĂ„n registreringsprocessen âą GenomgĂ„ng av lagstiftning och diskussion med berörda myndigheterTotalt har 38 metaboliter frĂ„n vĂ€xtskyddsmedel identifierats som relevanta att analysera i svenska yt- och grundvatten. Fyra av metaboliterna ingĂ„r redan i analyserna inom NMĂ, fyra kan inkluderas i NMĂ-analyserna frĂ„n och med 2024 och en metabolit kan inkluderas i en ny metod för mycket polĂ€ra Ă€mnen som utvecklas med finansiering av NaturvĂ„rdsverket. De resterande kommer att testas efter prioritering i samrĂ„d med berörda myndigheter.Identifiering av relevanta metaboliter att inkludera i den nationella miljöövervakningen, och i analyser av yt- och grundvatten generellt, behöver vara en kontinuerlig process eftersom nya Ă€mnen tillkommer pĂ„ marknaden och kunskapen kring befintliga Ă€mnen utvecklas. Att CKB fĂ„r uppgifter frĂ„n Kemikalieinspektionen tvĂ„ gĂ„nger per Ă„r sĂ€kerstĂ€ller att detta fortsĂ€tter att uppmĂ€rksammas.Av ekonomiska skĂ€l kan bara ett begrĂ€nsat antal metaboliter inkluderas i den löpande nationella miljöövervakningen och en prioritering behöver dĂ€rför göras. Denna prioritering bör göras i samrĂ„d med NaturvĂ„rdsverket och Kemikalieinspektionen och eventuellt andra berörda myndigheter
Identification of Pesticide Transformation Products in Surface Water Using Suspect Screening Combined with National Monitoring Data
Pesticides are widespread anthropogenic chemicals and well-known environmental contaminants of concern. Much less is known about transformation products (TPs) of pesticides and their presence in the environment. We developed a novel suspect screening approach for not well-explored pesticides (n = 16) and pesticide TPs (n = 242) by integrating knowledge from national monitoring with high-resolution mass spectrometry data. Weekly time-integrated samples were collected in two Swedish agricultural streams using the novel Time-Integrating, MicroFlow, In-line Extraction (TIMFIE) sampler. The integration of national monitoring data in the screening approach increased the number of prioritized compounds approximately twofold (from 23 to 42). Ultimately, 11 pesticide TPs were confirmed by reference standards and 12 TPs were considered tentatively identified with varying levels of confidence. Semiquantification of the newly confirmed TPs indicated higher concentrations than their corresponding parent pesticides in some cases, which highlights concerns related to (unknown) pesticide TPs in the environment. Some TPs were present in the environment without co-occurrence of their corresponding parent compounds, indicating higher persistency or mobility of the identified TPs. This study showcased the benefits of integrating monitoring knowledge in this type of studies, with advantages for suspect screening performance and the possibility to increase relevance of future monitoring programs
Pollinators, pests and yield-Multiple trade-offs from insecticide use in a mass-flowering crop
Multiple trade-offs likely occur between pesticide use, pollinators and yield (via crop flowers) in pollinator-dependent, mass-flowering crops (MFCs), causing potential conflict between conservation and agronomic goals. To date, no studies have looked at both outcomes within the same system, meaning win-win solutions for pollinators and yield can only be inferred. Here, we outline a new framework to explore these trade-offs, using red clover (Trifolium pratense) grown for seed production as an example. Specifically, we address how the insecticide thiacloprid affects densities of seed-eating weevils (Protapion spp.), pollination rates, yield, floral resources and colony dynamics of the key pollinator, Bombus terrestris. Thiacloprid did not affect the amount of nectar provided by, or pollinator visitation to, red clover flowers but did reduce weevil density, correlating to increased yield and gross profit. In addition, colonies of B. terrestris significantly increased their weight and reproductive output in landscapes with (compared with without) red clover, regardless of insecticide use. Synthesis and applications. We propose a holistic conceptual framework to explore trade-offs between pollinators, pesticides and yield that we believe to be essential for achieving conservation and agronomic goals. This framework applies to all insecticide-treated mass-flowering crops (MFCs) and can be adapted to include other ecological processes. Trialling the framework in our study system, we found that our focal insecticide, thiacloprid, improved red clover seed yield with no detected effects on its key pollinator, B. terrestris, and that the presence of red clover in the landscape can benefit pollinator populations
- âŠ