A cleaning method for remove soluble salts from mortars and lithic materials
3. Risultati e conclusioni
Le concentrazioni medie di BC (ng/m3) nei diversi siti di campionamento per i mesi di luglio e ottobre sono riportati in Tabella 1 e Tabella 2.
Il monitoraggio del Black Carbon ha messo in luce che nel sito interno ad Area C le concentrazioni risultano sempre inferiori rispetto al sito esterno.
145 Tab. 1 – Concentrazioni medie di Black Carbon( dev.st) in ng/m3per i mesi diluglio 2014 e
ottobre 2014 nei due siti Villa Necchi e Torre Sarca
Tab. 2 – Concentrazioni medie di Black Carbon ( dev.st) in ng/m3per i mesi di luglio 2015 e ottobre 2015 nei due siti Villa Necchi e edificio U9 (università Bicocca)
I dati ottenuti saranno ulteriormente elaborati al fine di indagare in modo più approfondito le differenze, in termini di concentrazione e di andamenti giornalieri, riscontrate nei siti di campionamento.
Bibliografia
[1] INEMAR 2010
[2]Perrone, M., Zhou J., Malandrino M., Sangiorgi, G., Rizzi, C., Ferrero L., Dommen J., Bolzacchini E. (2016).“PM chemical composition and oxidative potential of the soluble fraction of particles at two sites in the urban area of Milan, Northern Italy‖. Atmospheric Environment
128,104-113.
[3] Invernizzi G., Ruprecht A. , Mazza R. , De Marco C., Mocnik G. , Sioutas C. , Westerdahl D.: “Measurement of black carbon concentration as an indicator of air quality benefits of traffic restriction policies within the ecopass zone in Milan, Italy.”, Atmospheric Environment 45, 3522-3527, 2011.
Villa Necchi Torre Sarca
Luglio 2014 970(378) 2028 (651)
Ottobre 2014 2218 (1039 4448 (2646)
Villa Necchi U9
Luglio 2015 997(329) 1112(384)
146 Prediction and screening of the human biotransformation half-lives of heterogeneous
substancesby in silico approaches
Ester Papa1,2[email protected], Alessandro Sangion1,2and Paola Gramatica1 1Dipartimento di Scienze Teoriche ed Applicate, Università degli studi dell‟Insubria, 21100, Varese,Italy
2Laboratoire ITODYS, UMR7086, Université Paris Diderot, Paris, 75013, France
1. Introduction
The experimental determination of specific parameters to quantify processes that characterise bioaccumulation, such as uptake, metabolism and excretionis challenging due to the extensive costs and the time required to perform bioaccumulation testing. However, in the last years efforts have been made to generate in silico models based on Quantitative Structure-Activity Relationships (QSARs) in order to predict several parameters, such as bioconcentration factors, elimination and primary biotransformation rate constants and corresponding half-lives, from the molecular structure of chemical substances [1-3].
These in silicotools are particularly useful considering that bioaccumulation potential is a key point in risk assessment procedures. Therefore, the application of such models may support the risk assessment process of existing chemicals in the presence of limited experimental data. Additionally itmay reduce the experimental costs and impact on animal lives, as required by the European REACH regulation. Finally, these models can support the design of safer products by predicting the potential elimination and biotransformation half-lives of not yet synthesized chemicals at a preliminary screening phase [4-7].
In this study different QSAR models were generated for the prediction of half-livesderived from the total elimination- and the primary biotrasformation rates (HLT, HLB; days) measured in humans, for over 1000 organic compounds representative for known (such as Polychlorobiphenyls (PCBs)) or emerging pollutants (i.e. Pharmaceuticals and Personal Care Products (PPCPs)).
2. Results and discussion
QSAR models were developed for five independent datasets reported in the literature including data for 1105 substances. Dataset 1 (HLT)listedmeasures of the whole body total elimination half-lives. Datasets 2-5 (HLB1-HLB4) listed measures of primary biotransformation half-lives, where the
“primary biotransformation is defined as the conversion (elimination) of the parent chemical through reaction into another chemical (metabolite)” [2]. Mono- and bi-dimensional theoretical
molecular descriptors were calculated from simplified molecular-input line entry system (SMILES) notations by the freely available software PaDEL Descriptors [8].
The Genetic Algorithm Variable Subset Selection optimized for Multiple Linear Regression (MLR-Ordinary Least Squares(OLS) method) was performed in the software QSARINS [9].
All the QSARs were developed in compliance with the Guidance Document on the Validation of (Q)SAR Models [10], i.e. particular attention was paid to statistical robustness and external predictivity, applicability domain and interpretability.
The performances of the six QSAR models were always good with R2 range between 0.78 and 0.80 and Q2 range between 0.76 and 0.79. The predictive performances of these models as well as the applicability domainwere additionally tested on independent, external, prediction sets. The good results (averaged Q2ext.: 0.76) confirmed the predictive ability of the models, which were suitable to screen the HLT and HLBpotential for 500 compounds in the prediction sets.
These QSARs were thenapplied to predict the potential for elimination/biotransformation ofadditional substances, i.e. over 1100 Pharmaceuticals and Personal Care Products (PPCPs). Additionally, previously published models were applied to predict the biotransformation potential in fish, and the potential behavior of the 1100 PPCPs as Persistent, Bioaccumulative, and Toxic compounds (i.e. PBTs) [3,4].
147 Finally, the Principal Components Analysis (PCA) was applied to combine all the data predicted by the afore-mentioned models.This analysis allowed for the distinction of the PPCPs slowly biotransformed/eliminated, among those with potential PBT behavior.
3. Conclusions
The human biotransformation and elimination half-lives of over 2000 substances were studied by in
silico modelling and multivariate analysis. Results demonstrated that the proposed approaches are
useful tools not only to fill data gaps and to identify substances of potential human and environmental concern (i.e. slowly metabolized/ slowly eliminated), but also to screen new chemicals and to refine previous assessments, such as the potential PBT behaviour.
Bibliografia
[1] T.N. Brown, J.A. Arnot, F. Wania (2012) Iterative fragment selection: A group contribution approach to predicting fish biotransformation half-lives. Environ. Sci. Technol. 46, 8253−8260.
[2] J.A. Arnot, T.N. Brown, F. Wania (2014) Estimating Screening-Level Organic Chemical Half-Lives in Humans Environ. Sci. Technol. 48, 723−730
[3] E. Papa, L. van der Wal. J.A. Arnot, P. Gramatica (2014) Metabolic biotransformation half-lives in fish: QSAR modeling and consensus analysis Sci Total Environ. 470-471, 1040-6. [4] E. Papa, P. Gramatica (2010) QSPR as a support for the EU REACH regulation and rational design of environmentally safer chemicals: PBT identification from molecular structure Green Chem. 12, 836-843.
[5] P. Gramatica, S. Cassani A. Sangion (2015) PBT Assessment and Prioritization by PBT Index and Consensus Modeling: Comparison of Screening Results from Structural Models, Environ. Intern. 77C, 25-34.
[6] S. Cassani and P. Gramatica (2015) Identification of potential PBT behavior of Personal Care Products by structural approaches,Sustainable Chem. Pharm. 1, 19-27.
[7] A. Sangion and P. Gramatica (2016) PBT assessment and prioritization of Contaminants of Emerging Concern: PharmaceuticalsEnviron. Res. 147, 297-306.
[8] C.W. Yap (2011) PaDEL-descriptor: an open source software to calculate molecular descriptors and fingerprints J Comput Chem. 32, 1466-74.
[9] P. Gramatica, N. Chirico, E. Papa, S. Cassani, S. Kovarich (2013) QSARINS: A new software for the development, analysis, and validation of QSAR MLR models J. Comput. Chem. 34, 2121–213.
[10] Organization for the Economic Co-operation and Development (2007) Guidance
Document on the Validation of (Q)SAR Models.
http://www.oecd.org/officialdocuments/publicdisplaydocumentpdf/?doclanguage=en&cote=env/jm/ mono(2007)2
148 Cadmium concentrations in grains of durum wheat cultivars
Marzia Vergine1[email protected], Maria Siciliano1, Alessio Aprile1, Erika Sabella1,Alessandra Genga1and Luigi De Bellis1
1Dipartimento di Scienze Biologiche, Università del Salento, Lecce, Apulia, 73100, Italy 1. Introduction
The heavy metal cadmium (Cd) is a toxic metal and a nonessential element that affects negatively plant growth and development. Cd in soil is a result of its natural presence, application of phosphate fertilizers or sewage sludge to agricultural land, atmospheric deposition or rainfall.
Cd is water soluble and enters the plant partially through passive [1] but mostly through active transport systems [2] in the plasma membrane of root cells, similar to zinc (Zn) [3]. Soil properties can influence the availability of Cd for plant uptake.Durum wheat (Triticum turgidum L. ssp. durum),of course,accumulates Cd in grains when grown in Cd contaminated soils.
The Cd input results largely from trace amounts of cadmium in foodstuffs that are taken up from soils and waters. Consequently, most of the cadmium assumed by humans through the food chain comes from edible crops and cereals, and in particular from wheat.
Elevated levels of Cd in humans can cause kidney damage and renal dysfunction. Another disease associated with Cd exposure is the ―Itai–Itai‖, disease developed in post-menopausal Japanese women with low iron and zinc levels ingesting cadmium-contaminated rice. In addition, Cd can bind to DNA causing strand breaks and chromosome aberrations [4], which could lead to cancer-causing mutations.Since cadmium accumulation in foods represents a risk for the consumer health, the international trade organizations limit the acceptable concentration of Cd in edible crops.
Thus, it is necessary to decrease Cd accumulation in cereals aimed for food production, particularly in wheat which is one of the most frequently consumed cereals.
Here we report the result obtained from hydroponics study aimed to investigate Cd uptake and accumulation in selected cultivars of durum wheat.
2. Results and discussions
Two near-isogenic lines (Triticum turgidum L. ssp. durum) with opposite behavior in relation to cadmium low or high accumulation in kernels were used: TL 8982-H (High-Cd) and TL 8982-L (Low-Cd). Moreover, twelve commercial cultivars of durum wheat were grown in the same conditions: Creso, Svevo, Arcangelo, Strongfield, Maestrale, Cirillo, Aziziah, Parsifal, Aureo, Iride, Cappelli, Russello. Cd treatments were set up adding 0.5 µM of Cd to hydroponic solution.Plants were grown in hydroponic conditions as described by Harris and Taylor 2013 [5]. The samples of roots and leaves were collected 50 days after germination (at the beginning of tillering stages) and the grains at maturity, in three replicates. 0.1 g of dried sample was powdered in a mortar and mineralized. Samples were transferred into a 20 ml flask and diluted to the mark with deionized water: this solution was analyzed by atomic absorption spectrophotometer with Zeeman background correction (GF-AAS, Pinnacle, PerkinElmer, USA). The same samples were analyzed by atomic absorption (GF-AAS) to quantify the levels accumulated in roots, leaves and grains.
About the 80% of the plant Cd is located in root as already described by Harris and Taylor (2013) [5]. Moreover, no Cd content difference was found in near isogenic line Low-Cd roots and High-Cd roots. On the contrary, differences were found in leaves and grains. In particular, Low-Cd accumulates about 0.2 µg/g in leaves and grains, whereas High-Cd genotype accumulates 4-times higher Cd concentrations.Subsequently, in commercial cultivars the obtained data show that Aureo is the genotype with lower levels of Cd (0.18 µg/g) whereas Maestrale and Svevo accumulate Cd concentrations two-times higher.The Cd content of the other analyzed genotypes ranged between the values observed in Low and High Cd near isogenic lines.
149 3. Conclusions
The obtained data suggest that durum wheat accumulates the same amount of Cd in roots but they have different efficiency in Cd translocation from roots to leaves and grains. These results indicate the importance of studying Cd speciation, bioaccumulation and cycling in the environment for the management of agricultural soils and crops.
Choosing crop species or varieties with low metal transfer factors is one effective approach to reduce Cd contamination inwheat-derived foodstuffs.
References
[1] H. Kudo, K. Kudo, H. Amboc, M. Uemuraa, S. Kawai (2011) Cadmium sorption to plasma membrane isolated from barley roots is impeded by copper association onto membranes. Plant Sci 180, 300-305.
[2] C.A. Grant, W.T. Buckley, L.D. Bailey, F. Selles (1998) Cadmium accumulation in crops. Can J Plant Sci 78, 1-17.
[3] J.J. Hart, R.M. Welch, W.A.Norvell, L.A. Sullivan, L.V. Kochian (1998) Characterization of cadmium binding, uptake, and translocation in intact seedlings of bread and durum wheat cultivars. Plant Physiol 116, 1413–1420.
[4] D. Beyersmann, S. Hechtenberg (1997) Cadmium, gene regulation, and cellular signalling in mammalian cells. Toxicol Appl Pharmacol 144, 247-261.
[5] N. S. Harris, G. J. Taylor (2013). Cadmium uptake and partitioning in durum wheat during grain filling. BMC Plant Biology 4, 1-12.
150 Sperimentazione in campo nell’ambito del progetto EDOC@WORK 3.0 (PON04a2_B) : risultati preliminari delle concentrazioni indoor ed outdoor di NO2 ed SO2 in un sito ad
elevata criticità ambientale.
1
Daniela Caracciolo [email protected],2,3Pierina Ielpo, 4Paola Fermo, 4Chiara Nomellini, 2Cristina Mangia, 2Umberto Rizza, 3Vito Felice Uricchio, 1Cosimino Malitesta
1Università del Salento, Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Lecce, Italy