Bioaccumulation of polycyclic aromatic hydrocarbons and survival of earthworms (Eisenia andrei) exposed to biochar amended soils

Biochar has a charcoal polycyclic aromatic structure which allows its long half-life in soil, making it an ideal tool for C sequestration and for adsorption of organic pollutants, but at the same time raises concerns about possible adverse impacts on soil biota. Two biochars were tested under laboratory-controlled conditions on Eisenia andrei earthworms: a biochar produced at low temperature from wine tree cuttings (WTB) and a commercial low tar hardwood lump charcoal (HLB). The avoidance test (48-h exposure) showed that earthworms avoid biochar-treated soil with rates higher than 16 t ha 121 for HLB and 64 t ha 121 for WTB. After 42 days, toxic effects on earthworms were observed even at application rates (100 t ha 121) that are generally considered beneficial for most crops. The concentration of HLB and WTB required to kill half of earthworms\u2019 population (LC50; 95 % confidence limits) in the synthetic OECD soil was 338 and 580 t ha 121, respectively. Accumulation of polycyclic aromatic hydrocarbons (PAH) in earthworms exposed to the two biochar types at 100 t ha 121 was tested in two soils of different texture. In biochar-treated soils, the average earthworm survival rates were about 64 % in the sandy and 78 % clay-loam soils. PAH accumulation was larger in the sandy soil and largest in soils amended with HLB. PAH with less than four rings were preferentially scavenged from the soil by biochars, and this behaviour may mask that of the more dangerous components (i.e. four to five rings), which are preferentially accumulated. Earthworms can accumulate PAH as a consequence of exposure to biochar-treated soils and transfer them along the food chain. Soil type and biochar quality are both relevant in determining PAH transfer

New personal protective equipment for cutting and shearing: Finger-safe

The personal protective equipment used in agriculture does not include specific devices and due to this fact they are not able to provide a suitable degree of protection of the operator. In particular, the hand is the part of the body that is more prone to serious injury (e.g. amputation). The aim of this study was to test new safety principals for reducing the risk of cutting. We performed 10 types of different tests that led us to the identification of gloves resistant to mechanical action as well as to cutting. The prototype has demonstrated a high protective efficiency against tools such as pneumatic or manual scissors. In conclusion, the study recommends the use of gloves with elements which absorb and dissipate energy and not just simple cut resistant gloves. \ua9 2015 Sirio R. S. Cividino et al

Risk analysis of agricultural, forestry and green maintenance working sites

This work is focused on serious and fatal accidents which occur at forestry, agricultural and green maintenance working sites. In these sites are performed operations related to tree cutting or felling with continuous use of chainsaws. During this study we investigated 123 professional as well as non-professional working sites. We considered all characteristics necessary to determine the operating conditions and to identify possible steps for an effective protection. The work highlights a very serious situation in both investigated working environments where all measures of job safety are systematically ignored. In conclusion, we recommend that for a significant reduction of serious and fatal accidents, a mandatory training should be extended to all chainsaws users. Passive and active safety systems which interrupt the operation of the saw when it does not comply with all obligatory safety rules (i.e. human vicinity to cutting chain, falling down of the operator and others) should be define

Supplementary data for the article: Grbović, G.; Malev, O.; Dolenc, D.; Klobučar, R. S.; Cvetković, Z.; Cvetković, B.; Jovančicévić, B.; Trebše, P. Synthesis, Characterisation and Aquatic Ecotoxicity of the UV Filter Hexyl 2-(4-Diethylamino-2-Hydroxybenzoyl)Benzoate (DHHB) and Its Chlorinated by-Products. Environmental Chemistry 2016, 13 (1), 119–126. https://doi.org/10.1071/EN15013

Supplementary material for: [https://doi.org/10.1071/EN15013]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2020

Predictive Capability of QSAR Models Based on the CompTox Zebrafish Embryo Assays: An Imbalanced Classification Problem

The CompTox Chemistry Dashboard (ToxCast) contains one of the largest public databases on Zebrafish (Danio rerio) developmental toxicity. The data consists of 19 toxicological endpoints on unique 1018 compounds measured in relatively low concentration ranges. The endpoints are related to developmental effects occurring in dechorionated zebrafish embryos for 120 hours post fertilization and monitored via gross malformations and mortality. We report the predictive capability of 209 quantitative structure–activity relationship (QSAR) models developed by machine learning methods using penalization techniques and diverse model quality metrics to cope with the imbalanced endpoints. All these QSAR models were generated to test how the imbalanced classification (toxic or non-toxic) endpoints could be predicted regardless which of three algorithms is used: logistic regression, multi-layer perceptron, or random forests. Additionally, QSAR toxicity models are developed starting from sets of classical molecular descriptors, structural fingerprints and their combinations. Only 8 out of 209 models passed the 0.20 Matthew’s correlation coefficient value defined a priori as a threshold for acceptable model quality on the test sets. The best models were obtained for endpoints mortality (MORT), ActivityScore and JAW (deformation). The low predictability of the QSAR model developed from the zebrafish embryotoxicity data in the database is mainly due to a higher sensitivity of 19 measurements of endpoints carried out on dechorionated embryos at low concentration

Supplementary data for the article: Grbović, G.; Malev, O.; Dolenc, D.; Klobučar, R. S.; Cvetković, Z.; Cvetković, B.; Jovančicévić, B.; Trebše, P. Synthesis, Characterisation and Aquatic Ecotoxicity of the UV Filter Hexyl 2-(4-Diethylamino-2-Hydroxybenzoyl)Benzoate (DHHB) and Its Chlorinated by-Products. Environmental Chemistry 2016, 13 (1), 119–126. https://doi.org/10.1071/EN15013

Supplementary material for: [https://doi.org/10.1071/EN15013]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2020

Utilization of the zebrafish model to unravel the harmful effects of biomass burning during Amazonian wildfires

Amazonian wildfires in 2019 have raised awareness about rainforest burning due to increased emissions of particulate matter and carbon. In the context of these emissions, by-products of lignin thermal degradation (i.e. methoxyphenols) are often neglected. Methoxyphenols entering the atmosphere may form intermediates with currently unknown reaction mechanisms and toxicity. This study for the first time provides a comprehensive insight into the impact of lignin degradation products [guaiacol, catechol], and their nitrated intermediates [4-nitrocatechol, 4, 6- dinitroguaiacol, 5-nitroguaiacol] on zebrafish Danio rerio. Results revealed 4-nitrocatechol and catechol as the most toxic, followed by 4, 6DNG > 5NG > GUA. The whole-organism bioassay integrated with molecular modeling emphasized the potential of methoxyphenols to inhibit tyrosinase, lipoxygenase, and carbonic anhydrase, consequently altering embryonic development (i.e. affected sensorial, skeletal, and physiological parameters, pigmentation formation failure, and non-hatching of larvae). The whole-organism bioassay integrated with in silico approach confirmed the harmful effects of lignin degradation products and their intermediates on aquatic organisms, emphasizing the need for their evaluation within ecotoxicity studies focused on aquatic compartments

Flocculation of sewage sludge with FeCl3 modifies the bioavailability of potentially toxic elements when added to different soils

The effect of sewage sludge (SS) flocculation with FeCl3 on biological availability of Zn, Ni, Cd and Cu in oilseed rape (Brassica napus) plants grown on a acid and a neutral soil were studied during a greenhouse incubation experiment. The experiment included the following treatments: (i) unamended control soil, (ii) sewage sludge amended soils kept bare throughout the experiment and (iii) sewage sludge amended soil planted with oilseed rape. Amended soils received untreated or FeCl3 treated SS at a rate equivalent to 75 t d. w. ha-1 y-1. Plant growth was enhanced by addition of both untreated and FeCl3 treated SS, but sludge treated with FeCl3 produced a lower shoot dry matter than untreated SS, particularly in the acid soil. Evaluation of biological availability of potentially toxic elements (PTE) was performed by three different methods: plant shoot analysis, single DTPA-extraction and sequential fractionation procedure (SEP). After 50 days, accumulation of PTE was considerably larger in plant shoots grown on the acid soil and amended with FeCl3 treated sludge. Conversely, the FeCl3 treated SS reduced Cd, Ni and Zn accumulation in shoots in the neutral soil. Copper was generally unaffected by SS treatment in both soils. Plants decreased significantly the DTPA-extractability of Cd, Ni and Zn in both soils that received Fe-SS, but they did not change it in soils that received untreated SS. These different behaviours may be explained by the different mechanism involved in metals stabilization in the two soils: adsorption on Fe and Mn oxides in the neutral soil, precipitation and organic complexation in the acid soil. The chemical flocculation treatment of waste water with FeCl3 reduces PTE availability in neutral soils amended with SS, but markedly increases their solubility and bio-availability in acid soils. Therefore, the application of SS obtained from flocculation with FeCl3 should be restricted to neutral or calcareous soils

Utilization of the zebrafish model to unravel the harmful effects of biomass burning during Amazonian wildfires

Amazonian wildfires in 2019 have raised awareness about rainforest burning due to increased emissions of particulate matter and carbon. In the context of these emissions, by-products of lignin thermal degradation (i.e. methoxyphenols) are often neglected. Methoxyphenols entering the atmosphere may form intermediates with currently unknown reaction mechanisms and toxicity. This study for the first time provides a comprehensive insight into the impact of lignin degradation products [guaiacol, catechol], and their nitrated intermediates [4-nitrocatechol, 4,6-dinitroguaiacol, 5-nitroguaiacol] on zebrafish Danio rerio. Results revealed 4-nitrocatechol and catechol as the most toxic, followed by 4,6DNG > 5NG > GUA. The whole-organism bioassay integrated with molecular modeling emphasized the potential of methoxyphenols to inhibit tyrosinase, lipoxygenase, and carbonic anhydrase, consequently altering embryonic development (i.e. affected sensorial, skeletal, and physiological parameters, pigmentation formation failure, and non-hatching of larvae). The whole-organism bioassay integrated with in silico approach confirmed the harmful effects of lignin degradation products and their intermediates on aquatic organisms, emphasizing the need for their evaluation within ecotoxicity studies focused on aquatic compartments