499 research outputs found
Optimiranje priprave karbamatne ionoselektivne elektrode s kemijsko obdelavo srebrne žice : diplomsko delo visokošolskega študija
No full textCase studies on the Development and Application of in silico Techniques for Environmental hazard and Risk assessment (CADASTER)
No full textOkoljski standardi kakovosti za kovine v okviru Vodne direktive z upoštevanjem njihove biorazpoložljivosti
No full textMetals are naturally present in surface waters. By considering the bioavailability of a metal in an aquatic environment, we can more precisely predict the effect of a selected metal on aquatic organisms. This enables us to make a more reliable assessment of the compliance of the metal\u27s concentration in inland surface waters with the environmental quality standard for that metal. In addition to complex-forming inorganic and organic ligands, the bioavailability of metals in water is also influenced by physicochemical conditions in the water. Metals occur in different concentrations and in different forms in aquatic environments. This is referred to as metal speciation. The bioavailability of a metal in water depends mainly on its speciation. Normally, a dissolved free metal ion is more bioavailable than a metal ion bound in a complex. The risks posed by given metals to aquatic environments are addressed under EU legislation in the Water Framework Directive (Council of the European Union, 2000) (WFD). The WFD’s purpose is to direct Member States to protect and improve the status of all water bodies throughout the European Union. Directive 2013/39/EC (Council of the European Union, 2013), which refers to priority substances as regards water policy, supplements the WFD and the Directive on environmental quality standards (Council of the European Union, 2008). For nickel and lead, Directive 2013/39/EC sets the annual average environmental quality standards (AA-EQS) for inland surface waters, which refer to biologically available concentrations of metals (AA-EQSbioavailable). In this way, uniform environmental quality standards for the entire European Union are determined for metals, allowing for a compliance assessment of metals for surface waters. In the article, we have presented an analysis of inland surface water monitoring data for nickel and lead, examining how the introduction of AA-EQSbioavailable affects the consistency of monitoring data for these metals. We used monitoring data from 2018 to 2021. To calculate bioavailable concentrations for nickel and lead, we used the bioavailability assessment model bio-met bioavailability tool v.2.3 (Bio-met, 2017). Additionally, for lead, we used equations (1), (2), and (3) to calculate the bioavailable concentration (European Commission, 2019). Based on the analysis conducted, we recommend the utilization of the bio-met model instead of the equations for calculating the concentration of bioavailable lead in the context of the annual compliance assessment of inland surface water monitoring data carried out by ARSO. Using the mentioned bioavailability assessment model, we have provided an upgrade in the methods used to assess metal’s concentration compliance with the EQS for that metal for surface waters. As a result, the requirements of Directive 2013/39/EC relating to biologically available concentrations of metals could be transferred to the Slovenian legal system.Kovine so naravno prisotne v površinskih vodah. Z upoštevanjem biorazpoložljivosti izbrane kovine v vodnem okolju lahko bolj natančno predvidimo, kakšen učinek ima kovina na organizem. To nam omogoča, da izvedemo bolj zanesljivo oceno skladnosti koncentracije kovine v notranjih površinskih vodah z okoljskim standardom kakovosti za to kovino. Na biorazpoložljivost kovine v vodi poleg anorganskih in organskih ligandov, ki tvorijo komplekse, vplivajo tudi fizikalno-kemijski pogoji v vodi. Kovine se v vodnem okolju pojavljajo v različnih koncentracijah in oblikah. To se imenuje speciacija kovin. Biorazpoložljivost kovine v vodi je odvisna predvsem od speciacije. Običajno je raztopljeni prosti ion kovine bolj biorazpoložljiv kot ion kovine, vezan v kompleks. Tveganja, ki jih kovine predstavljajo za vodno okolje, so v okviru zakonodaje EU obravnavana tudi v Vodni direktivi (Council of the European Union, 2000), katere naloga je usmerjanje držav članic pri izboljšanju oziroma ohranjanju stanja vseh vodnih teles znotraj EU. Direktiva 2013/39/ES (Council of the European Union, 2013) v zvezi s prednostnimi snovmi na področju vodne politike dopolnjuje Vodno direktivo in Direktivo o okoljskih standardih kakovosti (Council of the European Union, 2008). Direktiva 2013/39/ES za nikelj in svinec okoljski standard kakovosti za letno povprečje (LP-OSK) v celinskih površinskih vodah zamenjuje z OSK za biološko razpoložljive koncentracije (LP-OSKbiorazpoložljiv). Na ta način je za celotno Evropsko unijo predpisan enotni okoljski standard kakovosti. To omogoča enotno ocenjevanje skladnosti za kovine za vodno okolje. V članku smo prikazali analizo podatkov monitoringa celinskih površinskih voda za nikelj in svinec ter preverili, kako uvedba LP-OSKbiorazpoložljiv vpliva na skladnost podatkov monitoringa za ti kovini. Pri tem smo izhajali iz podatkov monitoringa med letoma 2018 in 2021. Za izračun biorazpoložljivih koncentracij za nikelj in svinec smo uporabili model za oceno biorazpoložljivosti bio-met bioavailability tool v.2.3 (Bio-met, 2017). Za svinec smo za izračun biorazpoložljive koncentracije uporabili tudi enačbe (1), (2) in (3) (European Commission, 2019). Na osnovi izvedene analize priporočamo, da se za letno oceno skladnosti spremljanja celinskih površinskih voda, ki jo izvaja ARSO, namesto enačb za izračun koncentracije biološko razpoložljivega svinca uporabi model bio-met. Z uporabo omenjenega modela za oceno biorazpoložljivosti smo na področju vrednotenja okoljskih standardov kakovosti za kovine in njihove spojine zagotovili nadgradnjo ocene skladnosti kovin za površinske vode. To je omogočilo prenos zahtev Direktive 2013/39/ES, ki se nanašajo na biološko razpoložljive koncentracije kovin, v slovenski pravni red
Safety and efficacy of a feed additive consisting of Limosilactobacillus reuteri (formerly Lactobacillus reuteri) DSM 32264 as a feed additive for cats (NBF Lanes s.r.l.)
No full textFollowing a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of a product consisting of Limosilactobacillus reuteri (formerly Lactobacillus reuteri) DSM 32264 as a zootechnical additive for cats. The additive is a preparation of viable cells of L. reuteri DSM 32264 and it has not been previously authorised as a feed additive in the European Union. The additive is intended for use in complete feed for cats at a minimum inclusion level of 6 × 10(9) colony forming units (CFU) per animal and day. In a previous opinion, the FEEDAP Panel could not conclude on the efficacy of L. reuteri DSM 32264 for cats. The applicant has provided supplementary information to support the efficacy of the additive for cats. Based on the data provided, the FEEDAP Panel concluded that L. reuteri DSM 32264 has the potential to improve faecal consistency by reducing the moisture content of stools from cats receiving the additive at 1 × 10(10) CFU/kg feed. However, the Panel had some reservations on the effects in the moisture content, which if maintained overtime, might cast doubts on the benefits on the long‐term use of the additive since it could lead to constipation
Assessment of the efficacy of a feed additive consisting of Limosilactobacillus reuteri (formerly Lactobacillus reuteri) DSM 32203 for dogs (NBF LANES)
No full textFollowing a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of Limosilactobacillus reuteri (formerly Lactobacillus reuteri) DSM 32203 as a zootechnical additive for dogs. The additive is a preparation of viable cells of L. reuteri DSM 32203 and it has not been previously authorised as a feed additive in the European Union. The additive is intended for use in complete feed for dogs at a minimum use level of 6 × 10(9) colony forming units (CFU) per animal and day. In a previous opinion, the FEEDAP Panel could not conclude on the efficacy of L. reuteri DSM 32203 for dogs. The applicant has provided supplementary information to support the efficacy of the additive to dogs. Based on the data provided, the FEEDAP Panel concludes that L. reuteri DSM 32203 has the potential to improve faecal consistency by reducing the moisture content of stools from dogs receiving the additive at 1 × 10(10) CFU/kg feed. However, the Panel has some reservations on the effects in the moisture content of stools, which if maintained over time might cast doubts on the benefits on the long‐term use of the additive since it could lead to constipation
Safety and efficacy of Levucell® SB (Saccharomyces cerevisiae CNCM I‐1079) as a feed additive for all pigs
No full textFollowing a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Levucell® SB when used in feed for suckling piglets, pigs for fattening and minor porcine species. Levucell® SB is the trade name for a feed additive based on viable cells of a strain Saccharomyces cerevisiae currently authorised as a zootechnical additive for weaned piglets, sows, chickens for fattening and minor poultry species for fattening. The applicant is now seeking authorisation as a zootechnical additive for use with all pigs. In the context of a previous opinion, the identity of the strain was confirmed, and according to the Qualified Presumption of Safety (QPS) approach to safety assessment, it was presumed safe for the target species, consumers of products from animals fed the additive and the environment. Since no concerns are expected from other components of the additive, Levucell® SB is also considered safe for the target species, including all pigs, consumers and the environment. Levucell® is not a skin or eye irritant or a skin sensitiser. Inhalation exposure is unlikely. Encapsulation used in the existing coated forms is not expected to introduce hazards for users. In previous opinions, Levucell® SB was found to have the potential to be efficacious in sows and weaned piglets at the dose of 1 9 109 colony forming units (CFU)/kg complete feedingstuffs. Since the dose proposed for use with all pigs is the same as that demonstrated to be effective in weaned piglets and sows, and it can be reasonably assumed that the mode of action is the same, the conclusion on efficacy for weaned piglets and sows can be extrapolated to all pigs. Therefore, the FEEDAP Panel concludes that Levucell® SB has the potential to be efficacious in all pigs at 1 9 109 CFU/kg feedingstuffs
Experimental Assessment of the Environmental Fate and Effects of Triazoles and Benzotriazole
No full textThe environmental fate and effects of triazoles and benzotriazoles are of concern within the context of chemical regulation. As part of an intelligent testing strategy, experimental tests were performed on endpoints that are relevant for risk assessment. The experimental tests included the assessment of eco-toxicity to an alga, a daphnid and zebrafish embryos, and the assessment of ready biodegradability. Triazole and benzotriazole compounds were selected for testing, based on existing toxicity data for vertebrate and invertebrate species, as well as on the principal component analysis of molecular descriptors aimed at selecting the minimum number of test compounds in order to maximise the chemical domain spanned for both compound classes. The experimental results show that variation in the toxicities of triazoles and benzotriazole across species was relatively minor; in general, the largest factor was approximately 20. The study conducted indicated that triazoles are not readily biodegradable.</p
Solid Phase Dosing and Sampling Technique To Determine Partition Coefficients of Hydrophobic Chemicals in Complex Matrixes
No full textDetermination of polymer−water and dissolved organic
carbon (DOC)−water distribution coefficients of very
hydrophobic chemicals (log KOW > 6) is not straightforward.
Poor water solubility of the test compounds complicates
the spiking and analysis of actual freely dissolved
concentrations. By dosing a system via a PDMS−fiber
and monitoring the depletion in the polymer, spiking and
analysis of concentrations in the aqueous phase are avoided,
and sorption to the polymer and other hydrophobic
phases can be determined easily and accurate. In this
publication we report the determination of poly(dimethylsiloxane) (PDMS)−water, and Aldrich humic acid−water distribution coefficients for six PAHs with log KOW
values varying from 4.56 to 6.85. The distribution coefficients
to a PDMS fiber (log Kf) and the DOC (log KDOC) range
from 3.86 to 5.39 and 4.78 to 7.43, respectively. Even for
the most hydrophobic compounds, the distribution coefficients
show small standard errors (≤0.05 log units). Therefore,
this method might be applied to determine sorption coefficients
of numerous, even more hydrophobic compounds, to
humic acids as well as other dissolved hydrophobic matrixes
Assessing bioaccumulation of polybrominated diphenyl ethers for aquatic species by QSAR modeling
No full textPolybrominated diphenyl ethers (PBDEs) are used as flame retardants in textiles, foams and plastics. Highly bioaccumulative with toxic effects including developmental neurotoxicity estrogen and thyroid hormones disruption, they are considered as persistent organic pollutants (POPs) and have been found in human tissues, wildlife and biota worldwide. But only some of them are banned from EU market.For the environmental fate studies of these compounds the bioconcentration factor (BCF) is one of the most important endpoints to start with. We applied quantitative structure–activity relationships techniques to overcome the limited experimental data and avoid more animal testing.The aim of this work was to assess the bioaccumulation of PBDEs by means of QSAR. First, a BCF dataset of specifically conducted experiments was modeled. Then the study was extended by predicting the bioaccumulation and biomagnification factors using some experimental values from the literature. Molecular descriptors were calculated using DRAGON 6. The most relevant ones were selected and resulting models were compared paying attention to the applicability domain.</p
Safety and efficacy of a feed additive consisting of endo‐1,4‐beta‐xylanase EC 3.2.1.8 produced by Bacillus subtilis LMG S‐15136 (Belfeed B MP/ML) for gestating sows (Puratos NV)
No full textAbstract Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of Belfeed B MP/ML as a feed additive for gestating sows when used at 10 IU/kg feed. The additive contains endo‐1,4‐b‐xylanase produced by a genetically modified strain of Bacillus subtilis (LMG S‐15136). The FEEDAP Panel concluded that the additive is safe for the target species at the proposed use level and that there are no concerns regarding the use of Belfeed B MP/ML for the consumers and for the environment. The two formulations of the additive were considered skin and eye irritants and respiratory sensitisers. The Panel concluded that the additive has the potential to be efficacious as a zootechnical additive in sows during the gestation period at 10 IU/kg feed
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